Pull cgroup updates from Tejun Heo:
- Waiman's cgroup2 cpuset support has been finally merged closing one
of the last remaining feature gaps.
- cgroup.procs could show non-leader threads when cgroup2 threaded mode
was used in certain ways. I forgot to push the fix during the last
cycle.
- A patch to fix mount option parsing when all mount options have been
consumed by someone else (LSM).
- cgroup_no_v1 boot param can now block named cgroup1 hierarchies too.
* 'for-4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup: Add named hierarchy disabling to cgroup_no_v1 boot param
cgroup: fix parsing empty mount option string
cpuset: Remove set but not used variable 'cs'
cgroup: fix CSS_TASK_ITER_PROCS
cgroup: Add .__DEBUG__. prefix to debug file names
cpuset: Minor cgroup2 interface updates
cpuset: Expose cpuset.cpus.subpartitions with cgroup_debug
cpuset: Add documentation about the new "cpuset.sched.partition" flag
cpuset: Use descriptive text when reading/writing cpuset.sched.partition
cpuset: Expose cpus.effective and mems.effective on cgroup v2 root
cpuset: Make generate_sched_domains() work with partition
cpuset: Make CPU hotplug work with partition
cpuset: Track cpusets that use parent's effective_cpus
cpuset: Add an error state to cpuset.sched.partition
cpuset: Add new v2 cpuset.sched.partition flag
cpuset: Simply allocation and freeing of cpumasks
cpuset: Define data structures to support scheduling partition
cpuset: Enable cpuset controller in default hierarchy
cgroup: remove unnecessary unlikely()
Merge misc updates from Andrew Morton:
- large KASAN update to use arm's "software tag-based mode"
- a few misc things
- sh updates
- ocfs2 updates
- just about all of MM
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (167 commits)
kernel/fork.c: mark 'stack_vm_area' with __maybe_unused
memcg, oom: notify on oom killer invocation from the charge path
mm, swap: fix swapoff with KSM pages
include/linux/gfp.h: fix typo
mm/hmm: fix memremap.h, move dev_page_fault_t callback to hmm
hugetlbfs: Use i_mmap_rwsem to fix page fault/truncate race
hugetlbfs: use i_mmap_rwsem for more pmd sharing synchronization
memory_hotplug: add missing newlines to debugging output
mm: remove __hugepage_set_anon_rmap()
include/linux/vmstat.h: remove unused page state adjustment macro
mm/page_alloc.c: allow error injection
mm: migrate: drop unused argument of migrate_page_move_mapping()
blkdev: avoid migration stalls for blkdev pages
mm: migrate: provide buffer_migrate_page_norefs()
mm: migrate: move migrate_page_lock_buffers()
mm: migrate: lock buffers before migrate_page_move_mapping()
mm: migration: factor out code to compute expected number of page references
mm, page_alloc: enable pcpu_drain with zone capability
kmemleak: add config to select auto scan
mm/page_alloc.c: don't call kasan_free_pages() at deferred mem init
...
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Merge tag 'for-4.21/block-20181221' of git://git.kernel.dk/linux-block
Pull block updates from Jens Axboe:
"This is the main pull request for block/storage for 4.21.
Larger than usual, it was a busy round with lots of goodies queued up.
Most notable is the removal of the old IO stack, which has been a long
time coming. No new features for a while, everything coming in this
week has all been fixes for things that were previously merged.
This contains:
- Use atomic counters instead of semaphores for mtip32xx (Arnd)
- Cleanup of the mtip32xx request setup (Christoph)
- Fix for circular locking dependency in loop (Jan, Tetsuo)
- bcache (Coly, Guoju, Shenghui)
* Optimizations for writeback caching
* Various fixes and improvements
- nvme (Chaitanya, Christoph, Sagi, Jay, me, Keith)
* host and target support for NVMe over TCP
* Error log page support
* Support for separate read/write/poll queues
* Much improved polling
* discard OOM fallback
* Tracepoint improvements
- lightnvm (Hans, Hua, Igor, Matias, Javier)
* Igor added packed metadata to pblk. Now drives without metadata
per LBA can be used as well.
* Fix from Geert on uninitialized value on chunk metadata reads.
* Fixes from Hans and Javier to pblk recovery and write path.
* Fix from Hua Su to fix a race condition in the pblk recovery
code.
* Scan optimization added to pblk recovery from Zhoujie.
* Small geometry cleanup from me.
- Conversion of the last few drivers that used the legacy path to
blk-mq (me)
- Removal of legacy IO path in SCSI (me, Christoph)
- Removal of legacy IO stack and schedulers (me)
- Support for much better polling, now without interrupts at all.
blk-mq adds support for multiple queue maps, which enables us to
have a map per type. This in turn enables nvme to have separate
completion queues for polling, which can then be interrupt-less.
Also means we're ready for async polled IO, which is hopefully
coming in the next release.
- Killing of (now) unused block exports (Christoph)
- Unification of the blk-rq-qos and blk-wbt wait handling (Josef)
- Support for zoned testing with null_blk (Masato)
- sx8 conversion to per-host tag sets (Christoph)
- IO priority improvements (Damien)
- mq-deadline zoned fix (Damien)
- Ref count blkcg series (Dennis)
- Lots of blk-mq improvements and speedups (me)
- sbitmap scalability improvements (me)
- Make core inflight IO accounting per-cpu (Mikulas)
- Export timeout setting in sysfs (Weiping)
- Cleanup the direct issue path (Jianchao)
- Export blk-wbt internals in block debugfs for easier debugging
(Ming)
- Lots of other fixes and improvements"
* tag 'for-4.21/block-20181221' of git://git.kernel.dk/linux-block: (364 commits)
kyber: use sbitmap add_wait_queue/list_del wait helpers
sbitmap: add helpers for add/del wait queue handling
block: save irq state in blkg_lookup_create()
dm: don't reuse bio for flushes
nvme-pci: trace SQ status on completions
nvme-rdma: implement polling queue map
nvme-fabrics: allow user to pass in nr_poll_queues
nvme-fabrics: allow nvmf_connect_io_queue to poll
nvme-core: optionally poll sync commands
block: make request_to_qc_t public
nvme-tcp: fix spelling mistake "attepmpt" -> "attempt"
nvme-tcp: fix endianess annotations
nvmet-tcp: fix endianess annotations
nvme-pci: refactor nvme_poll_irqdisable to make sparse happy
nvme-pci: only set nr_maps to 2 if poll queues are supported
nvmet: use a macro for default error location
nvmet: fix comparison of a u16 with -1
blk-mq: enable IO poll if .nr_queues of type poll > 0
blk-mq: change blk_mq_queue_busy() to blk_mq_queue_inflight()
blk-mq: skip zero-queue maps in blk_mq_map_swqueue
...
It can be useful to inhibit all cgroup1 hierarchies especially during
transition and for debugging. cgroup_no_v1 can block hierarchies with
controllers which leaves out the named hierarchies. Expand it to
cover the named hierarchies so that "cgroup_no_v1=all,named" disables
all cgroup1 hierarchies.
Signed-off-by: Tejun Heo <tj@kernel.org>
Suggested-by: Marcin Pawlowski <mpawlowski@fb.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
This fixes the case where all mount options specified are consumed by an
LSM and all that's left is an empty string. In this case cgroupfs should
accept the string and not fail.
How to reproduce (with SELinux enabled):
# umount /sys/fs/cgroup/unified
# mount -o context=system_u:object_r:cgroup_t:s0 -t cgroup2 cgroup2 /sys/fs/cgroup/unified
mount: /sys/fs/cgroup/unified: wrong fs type, bad option, bad superblock on cgroup2, missing codepage or helper program, or other error.
# dmesg | tail -n 1
[ 31.575952] cgroup: cgroup2: unknown option ""
Fixes: 67e9c74b8a ("cgroup: replace __DEVEL__sane_behavior with cgroup2 fs type")
[NOTE: should apply on top of commit 5136f6365c ("cgroup: implement "nsdelegate" mount option"), older versions need manual rebase]
Suggested-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
The previous patch in this series removed carrying around a pointer to
the css in blkg. However, the blkg association logic still relied on
taking a reference on the css to ensure we wouldn't fail in getting a
reference for the blkg.
Here the implicit dependency on the css is removed. The association
continues to rely on the tryget logic walking up the blkg tree. This
streamlines the three ways that association can happen: normal, swap,
and writeback.
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Fixes gcc '-Wunused-but-set-variable' warning:
kernel/cgroup/cpuset.c: In function 'cpuset_cancel_attach':
kernel/cgroup/cpuset.c:2167:17: warning:
variable 'cs' set but not used [-Wunused-but-set-variable]
It never used since introduction in commit 1f7dd3e5a6 ("cgroup: fix handling
of multi-destination migration from subtree_control enabling")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Now that synchronize_rcu() waits for preempt-disable regions of code
as well as RCU read-side critical sections, synchronize_sched() can be
replaced by synchronize_rcu(). This commit therefore makes this change,
even though it is but a comment.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: "Dennis Zhou (Facebook)" <dennisszhou@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
CSS_TASK_ITER_PROCS implements process-only iteration by making
css_task_iter_advance() skip tasks which aren't threadgroup leaders;
however, when an iteration is started css_task_iter_start() calls the
inner helper function css_task_iter_advance_css_set() instead of
css_task_iter_advance(). As the helper doesn't have the skip logic,
when the first task to visit is a non-leader thread, it doesn't get
skipped correctly as shown in the following example.
# ps -L 2030
PID LWP TTY STAT TIME COMMAND
2030 2030 pts/0 Sl+ 0:00 ./test-thread
2030 2031 pts/0 Sl+ 0:00 ./test-thread
# mkdir -p /sys/fs/cgroup/x/a/b
# echo threaded > /sys/fs/cgroup/x/a/cgroup.type
# echo threaded > /sys/fs/cgroup/x/a/b/cgroup.type
# echo 2030 > /sys/fs/cgroup/x/a/cgroup.procs
# cat /sys/fs/cgroup/x/a/cgroup.threads
2030
2031
# cat /sys/fs/cgroup/x/cgroup.procs
2030
# echo 2030 > /sys/fs/cgroup/x/a/b/cgroup.threads
# cat /sys/fs/cgroup/x/cgroup.procs
2031
2030
The last read of cgroup.procs is incorrectly showing non-leader 2031
in cgroup.procs output.
This can be fixed by updating css_task_iter_advance() to handle the
first advance and css_task_iters_tart() to call
css_task_iter_advance() instead of the inner helper. After the fix,
the same commands result in the following (correct) result:
# ps -L 2062
PID LWP TTY STAT TIME COMMAND
2062 2062 pts/0 Sl+ 0:00 ./test-thread
2062 2063 pts/0 Sl+ 0:00 ./test-thread
# mkdir -p /sys/fs/cgroup/x/a/b
# echo threaded > /sys/fs/cgroup/x/a/cgroup.type
# echo threaded > /sys/fs/cgroup/x/a/b/cgroup.type
# echo 2062 > /sys/fs/cgroup/x/a/cgroup.procs
# cat /sys/fs/cgroup/x/a/cgroup.threads
2062
2063
# cat /sys/fs/cgroup/x/cgroup.procs
2062
# echo 2062 > /sys/fs/cgroup/x/a/b/cgroup.threads
# cat /sys/fs/cgroup/x/cgroup.procs
2062
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: "Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com>
Fixes: 8cfd8147df ("cgroup: implement cgroup v2 thread support")
Cc: stable@vger.kernel.org # v4.14+
Clearly mark the debug files and hide them by default by prefixing
".__DEBUG__.".
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Waiman Long <longman@redhat.com>
* Rename the partition file from "cpuset.sched.partition" to
"cpuset.cpus.partition".
* When writing to the partition file, drop "0" and "1" and only accept
"member" and "root".
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Waiman Long <longman@redhat.com>
For debugging purpose, it will be useful to expose the content of the
subparts_cpus as a read-only file to see if the code work correctly.
However, subparts_cpus will not be used at all in most use cases. So
adding a new cpuset file that clutters the cgroup directory may not be
desirable. This is now being done by using the hidden "cgroup_debug"
kernel command line option to expose a new "cpuset.cpus.subpartitions"
file.
That option was originally used by the debug controller to expose
itself when configured into the kernel. This is now extended to set an
internal flag used by cgroup_addrm_files(). A new CFTYPE_DEBUG flag
can now be used to specify that a cgroup file should only be created
when the "cgroup_debug" option is specified.
Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Currently, cpuset.sched.partition returns the values, 0, 1 or -1 on
read. A person who is not familiar with the partition code may not
understand what they mean.
In order to make cpuset.sched.partition more user-friendly, it will
now display the following descriptive text on read:
"root" - A partition root (top cpuset of a partition)
"member" - A non-root member of a partition
"root invalid" - An invalid partition root
Note that there is at least one partition in the whole cgroup hierarchy.
The top cpuset is the root of that partition. The rests are either a
root if it starts a new partition or a member of a partition.
The cpuset.sched.partition file will now also accept "root" and
"member" besides 1 and 0 as valid input values. The "root invalid"
value is internal only and cannot be written to the file.
Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Because of the fact that setting the "cpuset.sched.partition" in
a direct child of root can remove CPUs from the root's effective CPU
list, it makes sense to know what CPUs are left in the root cgroup for
scheduling purpose. So the "cpuset.cpus.effective" control file is now
exposed in the v2 cgroup root.
For consistency, the "cpuset.mems.effective" control file is exposed
as well.
Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
The generate_sched_domains() function is modified to make it work
correctly with the newly introduced subparts_cpus mask for scheduling
domains generation.
Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
When there is a cpu hotplug event (CPU online or offline), the partitions
may need to be reconfigured and regenerated. So code is added to the
hotplug functions to make them work with new subparts_cpus mask to
compute the right effective_cpus for each of the affected cpusets.
It may also change the state of a partition root from real one to an
erroneous one or vice versa.
Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
In the default hierarchy, a cpuset will use the parent's effective_cpus
if none of the requested CPUs can be granted from the parent. That can
be a problem if a parent is a partition root with children partition
roots. Changes to a parent's effective_cpus list due to changes in a
child partition root may not be properly reflected in a child cpuset
that use parent's effective_cpus because the cpu_exclusive rule of a
partition root will not guard against that.
In order to avoid the mismatch, two new tracking variables are added to
the cpuset structure to track if a cpuset uses parent's effective_cpus
and the number of children cpusets that use its effective_cpus. So
whenever cpumask changes are made to a parent, it will also check to
see if it has other children cpusets that use its effective_cpus and
call update_cpumasks_hier() if that is the case.
Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
When external events like CPU offlining or user events like changing
the cpu list of an ancestor cpuset happen, update_cpumasks_hier()
will be called to update the effective cpus of each of the affected
cpusets. That will then call update_parent_subparts_cpumask() if
partitions are impacted.
Currently, these events may cause update_parent_subparts_cpumask()
to return error if none of the requested cpus are available or it will
consume all the cpus in the parent partition root. Handling these errors
is problematic as the states may become inconsistent.
Instead of letting update_parent_subparts_cpumask() return error, a new
error state (-1) is added to the partition_root_state flag to designate
the fact that the partition is no longer valid. IOW, it is no longer a
real partition root, but the CS_CPU_EXCLUSIVE flag will still be set
as it can be changed back to a real one if favorable change happens
later on.
This new error state is set internally and user cannot write this new
value to "cpuset.sched.partition".
Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
A new cpuset.sched.partition boolean flag is added to cpuset v2.
This new flag, if set, indicates that the cgroup is the root of a
new scheduling domain or partition that includes itself and all its
descendants except those that are scheduling domain roots themselves
and their descendants.
With this new flag, one can directly create as many partitions as
necessary without ever using the v1 trick of turning off load balancing
in specific cpusets to create partitions as a side effect.
This new flag is owned by the parent and will cause the CPUs in the
cpuset to be removed from the effective CPUs of its parent.
This is implemented internally by adding a new subparts_cpus mask that
holds the CPUs belonging to child partitions so that:
subparts_cpus | effective_cpus = cpus_allowed
subparts_cpus & effective_cpus = 0
This new flag can only be turned on in a cpuset if its parent is a
partition root itself. The state of this flag cannot be changed if the
cpuset has children.
Once turned on, further changes to "cpuset.cpus" is allowed as long
as there is at least one CPU left that can be granted from the parent
and a child partition root cannot use up all the CPUs in the parent's
effective_cpus.
Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
The previous commit introduces a new subparts_cpus mask into the cpuset
data structure and a new tmpmasks structure. Managing the allocation
and freeing of those cpumasks is becoming more complex.
So a number of helper functions are added to simplify and streamline
the management of those cpumasks. To make it simple, all the cpumasks
are now pre-cleared on allocation.
Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
>From a cpuset point of view, a scheduling partition is a group of
cpusets with their own set of exclusive CPUs that are not shared by
other tasks outside the scheduling partition.
In the legacy hierarchy, scheduling partitions are supported indirectly
via the right use of the load balancing and the exclusive CPUs flag
which is not intuitive and can be hard to use.
To fully support the concept of scheduling partitions in the default
hierarchy, we need to add some new field into the cpuset structure as
well as a new tmpmasks structure that is used to pre-allocate cpumasks
at the top level cpuset functions to avoid memory allocation in inner
functions as memory allocation failure in those inner functions may
cause a cpuset to have inconsistent states.
Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Given the fact that thread mode had been merged into 4.14, it is now
time to enable cpuset to be used in the default hierarchy (cgroup v2)
as it is clearly threaded.
The cpuset controller had experienced feature creep since its
introduction more than a decade ago. Besides the core cpus and mems
control files to limit cpus and memory nodes, there are a bunch of
additional features that can be controlled from the userspace. Some of
the features are of doubtful usefulness and may not be actively used.
This patch enables cpuset controller in the default hierarchy with
a minimal set of features, namely just the cpus and mems and their
effective_* counterparts. We can certainly add more features to the
default hierarchy in the future if there is a real user need for them
later on.
Alternatively, with the unified hiearachy, it may make more sense
to move some of those additional cpuset features, if desired, to
memory controller or may be to the cpu controller instead of staying
with cpuset.
Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
WARN_ON() already contains an unlikely(), so it's not necessary to use
unlikely.
Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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Merge tag 'for-linus-20181102' of git://git.kernel.dk/linux-block
Pull block layer fixes from Jens Axboe:
"The biggest part of this pull request is the revert of the blkcg
cleanup series. It had one fix earlier for a stacked device issue, but
another one was reported. Rather than play whack-a-mole with this,
revert the entire series and try again for the next kernel release.
Apart from that, only small fixes/changes.
Summary:
- Indentation fixup for mtip32xx (Colin Ian King)
- The blkcg cleanup series revert (Dennis Zhou)
- Two NVMe fixes. One fixing a regression in the nvme request
initialization in this merge window, causing nvme-fc to not work.
The other is a suspend/resume p2p resource issue (James, Keith)
- Fix sg discard merge, allowing us to merge in cases where we didn't
before (Jianchao Wang)
- Call rq_qos_exit() after the queue is frozen, preventing a hang
(Ming)
- Fix brd queue setup, fixing an oops if we fail setting up all
devices (Ming)"
* tag 'for-linus-20181102' of git://git.kernel.dk/linux-block:
nvme-pci: fix conflicting p2p resource adds
nvme-fc: fix request private initialization
blkcg: revert blkcg cleanups series
block: brd: associate with queue until adding disk
block: call rq_qos_exit() after queue is frozen
mtip32xx: clean an indentation issue, remove extraneous tabs
block: fix the DISCARD request merge
On a system that executes multiple cgrouped jobs and independent
workloads, we don't just care about the health of the overall system, but
also that of individual jobs, so that we can ensure individual job health,
fairness between jobs, or prioritize some jobs over others.
This patch implements pressure stall tracking for cgroups. In kernels
with CONFIG_PSI=y, cgroup2 groups will have cpu.pressure, memory.pressure,
and io.pressure files that track aggregate pressure stall times for only
the tasks inside the cgroup.
Link: http://lkml.kernel.org/r/20180828172258.3185-10-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Daniel Drake <drake@endlessm.com>
Tested-by: Suren Baghdasaryan <surenb@google.com>
Cc: Christopher Lameter <cl@linux.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Johannes Weiner <jweiner@fb.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Enderborg <peter.enderborg@sony.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Vinayak Menon <vinmenon@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Merge tag 'for-4.20/block-20181021' of git://git.kernel.dk/linux-block
Pull block layer updates from Jens Axboe:
"This is the main pull request for block changes for 4.20. This
contains:
- Series enabling runtime PM for blk-mq (Bart).
- Two pull requests from Christoph for NVMe, with items such as;
- Better AEN tracking
- Multipath improvements
- RDMA fixes
- Rework of FC for target removal
- Fixes for issues identified by static checkers
- Fabric cleanups, as prep for TCP transport
- Various cleanups and bug fixes
- Block merging cleanups (Christoph)
- Conversion of drivers to generic DMA mapping API (Christoph)
- Series fixing ref count issues with blkcg (Dennis)
- Series improving BFQ heuristics (Paolo, et al)
- Series improving heuristics for the Kyber IO scheduler (Omar)
- Removal of dangerous bio_rewind_iter() API (Ming)
- Apply single queue IPI redirection logic to blk-mq (Ming)
- Set of fixes and improvements for bcache (Coly et al)
- Series closing a hotplug race with sysfs group attributes (Hannes)
- Set of patches for lightnvm:
- pblk trace support (Hans)
- SPDX license header update (Javier)
- Tons of refactoring patches to cleanly abstract the 1.2 and 2.0
specs behind a common core interface. (Javier, Matias)
- Enable pblk to use a common interface to retrieve chunk metadata
(Matias)
- Bug fixes (Various)
- Set of fixes and updates to the blk IO latency target (Josef)
- blk-mq queue number updates fixes (Jianchao)
- Convert a bunch of drivers from the old legacy IO interface to
blk-mq. This will conclude with the removal of the legacy IO
interface itself in 4.21, with the rest of the drivers (me, Omar)
- Removal of the DAC960 driver. The SCSI tree will introduce two
replacement drivers for this (Hannes)"
* tag 'for-4.20/block-20181021' of git://git.kernel.dk/linux-block: (204 commits)
block: setup bounce bio_sets properly
blkcg: reassociate bios when make_request() is called recursively
blkcg: fix edge case for blk_get_rl() under memory pressure
nvme-fabrics: move controller options matching to fabrics
nvme-rdma: always have a valid trsvcid
mtip32xx: fully switch to the generic DMA API
rsxx: switch to the generic DMA API
umem: switch to the generic DMA API
sx8: switch to the generic DMA API
sx8: remove dead IF_64BIT_DMA_IS_POSSIBLE code
skd: switch to the generic DMA API
ubd: remove use of blk_rq_map_sg
nvme-pci: remove duplicate check
drivers/block: Remove DAC960 driver
nvme-pci: fix hot removal during error handling
nvmet-fcloop: suppress a compiler warning
nvme-core: make implicit seed truncation explicit
nvmet-fc: fix kernel-doc headers
nvme-fc: rework the request initialization code
nvme-fc: introduce struct nvme_fcp_op_w_sgl
...
A cgroup which is already a threaded domain may be converted into a
threaded cgroup if the prerequisite conditions are met. When this
happens, all threaded descendant should also have their ->dom_cgrp
updated to the new threaded domain cgroup. Unfortunately, this
propagation was missing leading to the following failure.
# cd /sys/fs/cgroup/unified
# cat cgroup.subtree_control # show that no controllers are enabled
# mkdir -p mycgrp/a/b/c
# echo threaded > mycgrp/a/b/cgroup.type
At this point, the hierarchy looks as follows:
mycgrp [d]
a [dt]
b [t]
c [inv]
Now let's make node "a" threaded (and thus "mycgrp" s made "domain threaded"):
# echo threaded > mycgrp/a/cgroup.type
By this point, we now have a hierarchy that looks as follows:
mycgrp [dt]
a [t]
b [t]
c [inv]
But, when we try to convert the node "c" from "domain invalid" to
"threaded", we get ENOTSUP on the write():
# echo threaded > mycgrp/a/b/c/cgroup.type
sh: echo: write error: Operation not supported
This patch fixes the problem by
* Moving the opencoded ->dom_cgrp save and restoration in
cgroup_enable_threaded() into cgroup_{save|restore}_control() so
that mulitple cgroups can be handled.
* Updating all threaded descendants' ->dom_cgrp to point to the new
dom_cgrp when enabling threaded mode.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-and-tested-by: "Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com>
Reported-by: Amin Jamali <ajamali@pivotal.io>
Reported-by: Joao De Almeida Pereira <jpereira@pivotal.io>
Link: https://lore.kernel.org/r/CAKgNAkhHYCMn74TCNiMJ=ccLd7DcmXSbvw3CbZ1YREeG7iJM5g@mail.gmail.com
Fixes: 454000adaa ("cgroup: introduce cgroup->dom_cgrp and threaded css_set handling")
Cc: stable@vger.kernel.org # v4.14+
The previous patch in this series removed carrying around a pointer to
the css in blkg. However, the blkg association logic still relied on
taking a reference on the css to ensure we wouldn't fail in getting a
reference for the blkg.
Here the implicit dependency on the css is removed. The association
continues to rely on the tryget logic walking up the blkg tree. This
streamlines the three ways that association can happen: normal, swap,
and writeback.
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Dennis Zhou <dennisszhou@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull cgroup updates from Tejun Heo:
"Just one commit from Steven to take out spin lock from trace event
handlers"
* 'for-4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup/tracing: Move taking of spin lock out of trace event handlers
This change allows creating kernfs files and directories with arbitrary
uid/gid instead of always using GLOBAL_ROOT_UID/GID by extending
kernfs_create_dir_ns() and kernfs_create_file_ns() with uid/gid arguments.
The "simple" kernfs_create_file() and kernfs_create_dir() are left alone
and always create objects belonging to the global root.
When creating symlinks ownership (uid/gid) is taken from the target kernfs
object.
Co-Developed-by: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
It is unwise to take spin locks from the handlers of trace events.
Mainly, because they can introduce lockups, because it introduces locks
in places that are normally not tested. Worse yet, because trace events
are tucked away in the include/trace/events/ directory, locks that are
taken there are forgotten about.
As a general rule, I tell people never to take any locks in a trace
event handler.
Several cgroup trace event handlers call cgroup_path() which eventually
takes the kernfs_rename_lock spinlock. This injects the spinlock in the
code without people realizing it. It also can cause issues for the
PREEMPT_RT patch, as the spinlock becomes a mutex, and the trace event
handlers are called with preemption disabled.
By moving the calculation of the cgroup_path() out of the trace event
handlers and into a macro (surrounded by a
trace_cgroup_##type##_enabled()), then we could place the cgroup_path
into a string, and pass that to the trace event. Not only does this
remove the taking of the spinlock out of the trace event handler, but
it also means that the cgroup_path() only needs to be called once (it
is currently called twice, once to get the length to reserver the
buffer for, and once again to get the path itself. Now it only needs to
be done once.
Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
As we move stuff around, some doc references are broken. Fix some of
them via this script:
./scripts/documentation-file-ref-check --fix
Manually checked if the produced result is valid, removing a few
false-positives.
Acked-by: Takashi Iwai <tiwai@suse.de>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Stephen Boyd <sboyd@kernel.org>
Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Acked-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Coly Li <colyli@suse.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Jonathan Corbet <corbet@lwn.net>
- Use overflow helpers in 2-factor allocators (Kees, Rasmus)
- Introduce overflow test module (Rasmus, Kees)
- Introduce saturating size helper functions (Matthew, Kees)
- Treewide use of struct_size() for allocators (Kees)
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Merge tag 'overflow-v4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull overflow updates from Kees Cook:
"This adds the new overflow checking helpers and adds them to the
2-factor argument allocators. And this adds the saturating size
helpers and does a treewide replacement for the struct_size() usage.
Additionally this adds the overflow testing modules to make sure
everything works.
I'm still working on the treewide replacements for allocators with
"simple" multiplied arguments:
*alloc(a * b, ...) -> *alloc_array(a, b, ...)
and
*zalloc(a * b, ...) -> *calloc(a, b, ...)
as well as the more complex cases, but that's separable from this
portion of the series. I expect to have the rest sent before -rc1
closes; there are a lot of messy cases to clean up.
Summary:
- Introduce arithmetic overflow test helper functions (Rasmus)
- Use overflow helpers in 2-factor allocators (Kees, Rasmus)
- Introduce overflow test module (Rasmus, Kees)
- Introduce saturating size helper functions (Matthew, Kees)
- Treewide use of struct_size() for allocators (Kees)"
* tag 'overflow-v4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
treewide: Use struct_size() for devm_kmalloc() and friends
treewide: Use struct_size() for vmalloc()-family
treewide: Use struct_size() for kmalloc()-family
device: Use overflow helpers for devm_kmalloc()
mm: Use overflow helpers in kvmalloc()
mm: Use overflow helpers in kmalloc_array*()
test_overflow: Add memory allocation overflow tests
overflow.h: Add allocation size calculation helpers
test_overflow: Report test failures
test_overflow: macrofy some more, do more tests for free
lib: add runtime test of check_*_overflow functions
compiler.h: enable builtin overflow checkers and add fallback code
One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:
struct foo {
int stuff;
void *entry[];
};
instance = kmalloc(sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL);
Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:
instance = kmalloc(struct_size(instance, entry, count), GFP_KERNEL);
This patch makes the changes for kmalloc()-family (and kvmalloc()-family)
uses. It was done via automatic conversion with manual review for the
"CHECKME" non-standard cases noted below, using the following Coccinelle
script:
// pkey_cache = kmalloc(sizeof *pkey_cache + tprops->pkey_tbl_len *
// sizeof *pkey_cache->table, GFP_KERNEL);
@@
identifier alloc =~ "kmalloc|kzalloc|kvmalloc|kvzalloc";
expression GFP;
identifier VAR, ELEMENT;
expression COUNT;
@@
- alloc(sizeof(*VAR) + COUNT * sizeof(*VAR->ELEMENT), GFP)
+ alloc(struct_size(VAR, ELEMENT, COUNT), GFP)
// mr = kzalloc(sizeof(*mr) + m * sizeof(mr->map[0]), GFP_KERNEL);
@@
identifier alloc =~ "kmalloc|kzalloc|kvmalloc|kvzalloc";
expression GFP;
identifier VAR, ELEMENT;
expression COUNT;
@@
- alloc(sizeof(*VAR) + COUNT * sizeof(VAR->ELEMENT[0]), GFP)
+ alloc(struct_size(VAR, ELEMENT, COUNT), GFP)
// Same pattern, but can't trivially locate the trailing element name,
// or variable name.
@@
identifier alloc =~ "kmalloc|kzalloc|kvmalloc|kvzalloc";
expression GFP;
expression SOMETHING, COUNT, ELEMENT;
@@
- alloc(sizeof(SOMETHING) + COUNT * sizeof(ELEMENT), GFP)
+ alloc(CHECKME_struct_size(&SOMETHING, ELEMENT, COUNT), GFP)
Signed-off-by: Kees Cook <keescook@chromium.org>
Pull cgroup updates from Tejun Heo:
- For cpustat, cgroup has a percpu hierarchical stat mechanism which
propagates up the hierarchy lazily.
This contains commits to factor out and generalize the mechanism so
that it can be used for other cgroup stats too.
The original intention was to update memcg stats to use it but memcg
went for a different approach, so still the only user is cpustat. The
factoring out and generalization still make sense and it's likely
that this can be used for other purposes in the future.
- cgroup uses kernfs_notify() (which uses fsnotify()) to inform user
space of certain events. A rate limiting mechanism is added.
- Other misc changes.
* 'for-4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup: css_set_lock should nest inside tasklist_lock
rdmacg: Convert to use match_string() helper
cgroup: Make cgroup_rstat_updated() ready for root cgroup usage
cgroup: Add memory barriers to plug cgroup_rstat_updated() race window
cgroup: Add cgroup_subsys->css_rstat_flush()
cgroup: Replace cgroup_rstat_mutex with a spinlock
cgroup: Factor out and expose cgroup_rstat_*() interface functions
cgroup: Reorganize kernel/cgroup/rstat.c
cgroup: Distinguish base resource stat implementation from rstat
cgroup: Rename stat to rstat
cgroup: Rename kernel/cgroup/stat.c to kernel/cgroup/rstat.c
cgroup: Limit event generation frequency
cgroup: Explicitly remove core interface files
cgroup_enable_task_cg_lists() incorrectly nests non-irq-safe
tasklist_lock inside irq-safe css_set_lock triggering the following
lockdep warning.
WARNING: possible irq lock inversion dependency detected
4.17.0-rc1-00027-gb37d049 #6 Not tainted
--------------------------------------------------------
systemd/1 just changed the state of lock:
00000000fe57773b (css_set_lock){..-.}, at: cgroup_free+0xf2/0x12a
but this lock took another, SOFTIRQ-unsafe lock in the past:
(tasklist_lock){.+.+}
and interrupts could create inverse lock ordering between them.
other info that might help us debug this:
Possible interrupt unsafe locking scenario:
CPU0 CPU1
---- ----
lock(tasklist_lock);
local_irq_disable();
lock(css_set_lock);
lock(tasklist_lock);
<Interrupt>
lock(css_set_lock);
*** DEADLOCK ***
The condition is highly unlikely to actually happen especially given
that the path is executed only once per boot.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Boqun Feng <boqun.feng@gmail.com>
Variants of proc_create{,_data} that directly take a seq_file show
callback and drastically reduces the boilerplate code in the callers.
All trivial callers converted over.
Signed-off-by: Christoph Hellwig <hch@lst.de>
The new helper returns index of the matching string in an array.
We are going to use it here.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
cgroup_rstat_updated() ensures that the cgroup's rstat is linked to
the parent. If there's no parent, it never gets linked and the
function ends up grabbing and releasing the cgroup_rstat_lock each
time for no reason which can be expensive.
This hasn't been a problem till now because nobody was calling the
function for the root cgroup but rstat is gonna be exposed to
controllers and use cases, so let's get ready. Make
cgroup_rstat_updated() an no-op for the root cgroup.
Signed-off-by: Tejun Heo <tj@kernel.org>
cgroup_rstat_updated() has a small race window where an updated
signaling can race with flush and could be lost till the next update.
This wasn't a problem for the existing usages, but we plan to use
rstat to track counters which need to be accurate.
This patch plugs the race window by synchronizing
cgroup_rstat_updated() and flush path with memory barriers around
cgroup_rstat_cpu->updated_next pointer.
Signed-off-by: Tejun Heo <tj@kernel.org>
This patch adds cgroup_subsys->css_rstat_flush(). If a subsystem has
this callback, its csses are linked on cgrp->css_rstat_list and rstat
will call the function whenever the associated cgroup is flushed.
Flush is also performed when such csses are released so that residual
counts aren't lost.
Combined with the rstat API previous patches factored out, this allows
controllers to plug into rstat to manage their statistics in a
scalable way.
Signed-off-by: Tejun Heo <tj@kernel.org>
Currently, rstat flush path is protected with a mutex which is fine as
all the existing users are from interface file show path. However,
rstat is being generalized for use by controllers and flushing from
atomic contexts will be necessary.
This patch replaces cgroup_rstat_mutex with a spinlock and adds a
irq-safe flush function - cgroup_rstat_flush_irqsafe(). Explicit
yield handling is added to the flush path so that other flush
functions can yield to other threads and flushers.
Signed-off-by: Tejun Heo <tj@kernel.org>
cgroup_rstat is being generalized so that controllers can use it too.
This patch factors out and exposes the following interface functions.
* cgroup_rstat_updated(): Renamed from cgroup_rstat_cpu_updated() for
consistency.
* cgroup_rstat_flush_hold/release(): Factored out from base stat
implementation.
* cgroup_rstat_flush(): Verbatim expose.
While at it, drop assert on cgroup_rstat_mutex in
cgroup_base_stat_flush() as it crosses layers and make a minor comment
update.
v2: Added EXPORT_SYMBOL_GPL(cgroup_rstat_updated) to fix a build bug.
Signed-off-by: Tejun Heo <tj@kernel.org>
Currently, rstat.c has rstat and base stat implementations intermixed.
Collect base stat implementation at the end of the file. Also,
reorder the prototypes.
This patch doesn't make any functional changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Base resource stat accounts universial (not specific to any
controller) resource consumptions on top of rstat. Currently, its
implementation is intermixed with rstat implementation making the code
confusing to follow.
This patch clarifies the distintion by doing the followings.
* Encapsulate base resource stat counters, currently only cputime, in
struct cgroup_base_stat.
* Move prev_cputime into struct cgroup and initialize it with cgroup.
* Rename the related functions so that they start with cgroup_base_stat.
* Prefix the related variables and field names with b.
This patch doesn't make any functional changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
stat is too generic a name and ends up causing subtle confusions.
It'll be made generic so that controllers can plug into it, which will
make the problem worse. Let's rename it to something more specific -
cgroup_rstat for cgroup recursive stat.
This patch does the following renames. No other changes.
* cpu_stat -> rstat_cpu
* stat -> rstat
* ?cstat -> ?rstatc
Note that the renames are selective. The unrenamed are the ones which
implement basic resource statistics on top of rstat. This will be
further cleaned up in the following patches.
Signed-off-by: Tejun Heo <tj@kernel.org>
stat is too generic a name and ends up causing subtle confusions.
It'll be made generic so that controllers can plug into it, which will
make the problem worse. Let's rename it to something more specific -
cgroup_rstat for cgroup recursive stat.
First, rename kernel/cgroup/stat.c to kernel/cgroup/rstat.c. No
content changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
".events" files generate file modified event to notify userland of
possible new events. Some of the events can be quite bursty
(e.g. memory high event) and generating notification each time is
costly and pointless.
This patch implements a event rate limit mechanism. If a new
notification is requested before 10ms has passed since the previous
notification, the new notification is delayed till then.
As this only delays from the second notification on in a given close
cluster of notifications, userland reactions to notifications
shouldn't be delayed at all in most cases while avoiding notification
storms.
Signed-off-by: Tejun Heo <tj@kernel.org>
The "cgroup." core interface files bypass the usual interface removal
path and get removed recursively along with the cgroup itself. While
this works now, the subtle discrepancy gets in the way of implementing
common mechanisms.
This patch updates cgroup core interface file handling so that it's
consistent with controller interface files. When added, the css is
marked CSS_VISIBLE and they're explicitly removed before the cgroup is
destroyed.
This doesn't cause user-visible behavior changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Pull workqueue updates from Tejun Heo:
"rcu_work addition and a couple trivial changes"
* 'for-4.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
workqueue: remove the comment about the old manager_arb mutex
workqueue: fix the comments of nr_idle
fs/aio: Use rcu_work instead of explicit rcu and work item
cgroup: Use rcu_work instead of explicit rcu and work item
RCU, workqueue: Implement rcu_work
A domain cgroup isn't allowed to be turned threaded if its subtree is
populated or domain controllers are enabled. cgroup_enable_threaded()
depended on cgroup_can_be_thread_root() test to enforce this rule. A
parent which has populated domain descendants or have domain
controllers enabled can't become a thread root, so the above rules are
enforced automatically.
However, for the root cgroup which can host mixed domain and threaded
children, cgroup_can_be_thread_root() doesn't check any of those
conditions and thus first level cgroups ends up escaping those rules.
This patch fixes the bug by adding explicit checks for those rules in
cgroup_enable_threaded().
Reported-by: Michael Kerrisk (man-pages) <mtk.manpages@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Fixes: 8cfd8147df ("cgroup: implement cgroup v2 thread support")
Cc: stable@vger.kernel.org # v4.14+
Make current_cpuset_is_being_rebound return bool due to this particular
function only using either one or zero as its return value.
No functional change.
Link: http://lkml.kernel.org/r/1513266622-15860-4-git-send-email-baiyaowei@cmss.chinamobile.com
Signed-off-by: Yaowei Bai <baiyaowei@cmss.chinamobile.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
e7fd37ba12 ("cgroup: avoid copying strings longer than the buffers")
converted possibly unsafe strncpy() usages in cgroup to strscpy().
However, although the callsites are completely fine with truncated
copied, because strscpy() is marked __must_check, it led to the
following warnings.
kernel/cgroup/cgroup.c: In function ‘cgroup_file_name’:
kernel/cgroup/cgroup.c:1400:10: warning: ignoring return value of ‘strscpy’, declared with attribute warn_unused_result [-Wunused-result]
strscpy(buf, cft->name, CGROUP_FILE_NAME_MAX);
^
To avoid the warnings, 50034ed496 ("cgroup: use strlcpy() instead of
strscpy() to avoid spurious warning") switched them to strlcpy().
strlcpy() is worse than strlcpy() because it unconditionally runs
strlen() on the source string, and the only reason we switched to
strlcpy() here was because it was lacking __must_check, which doesn't
reflect any material differences between the two function. It's just
that someone added __must_check to strscpy() and not to strlcpy().
These basic string copy operations are used in variety of ways, and
one of not-so-uncommon use cases is safely handling truncated copies,
where the caller naturally doesn't care about the return value. The
__must_check doesn't match the actual use cases and forces users to
opt for inferior variants which lack __must_check by happenstance or
spread ugly (void) casts.
Remove __must_check from strscpy() and restore strscpy() usages in
cgroup.
Signed-off-by: Tejun Heo <tj@kernel.org>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ma Shimiao <mashimiao.fnst@cn.fujitsu.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Make cgroup.threads file delegatable.
The behavior of cgroup.threads should follow the behavior of cgroup.procs.
Signed-off-by: Roman Gushchin <guro@fb.com>
Discovered-by: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Deadlock during cgroup migration from cpu hotplug path when a task T is
being moved from source to destination cgroup.
kworker/0:0
cpuset_hotplug_workfn()
cpuset_hotplug_update_tasks()
hotplug_update_tasks_legacy()
remove_tasks_in_empty_cpuset()
cgroup_transfer_tasks() // stuck in iterator loop
cgroup_migrate()
cgroup_migrate_add_task()
In cgroup_migrate_add_task() it checks for PF_EXITING flag of task T.
Task T will not migrate to destination cgroup. css_task_iter_start()
will keep pointing to task T in loop waiting for task T cg_list node
to be removed.
Task T
do_exit()
exit_signals() // sets PF_EXITING
exit_task_namespaces()
switch_task_namespaces()
free_nsproxy()
put_mnt_ns()
drop_collected_mounts()
namespace_unlock()
synchronize_rcu()
_synchronize_rcu_expedited()
schedule_work() // on cpu0 low priority worker pool
wait_event() // waiting for work item to execute
Task T inserted a work item in the worklist of cpu0 low priority
worker pool. It is waiting for expedited grace period work item
to execute. This work item will only be executed once kworker/0:0
complete execution of cpuset_hotplug_workfn().
kworker/0:0 ==> Task T ==>kworker/0:0
In case of PF_EXITING task being migrated from source to destination
cgroup, migrate next available task in source cgroup.
Signed-off-by: Prateek Sood <prsood@codeaurora.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
As long as cft->name is guaranteed to be NUL-terminated, using strlcpy() would
work just as well and avoid that warning, so the change below could be folded
into that commit.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
cgroup root name and file name have max length limit, we should
avoid copying longer name than that to the name.
tj: minor update to $SUBJ.
Signed-off-by: Ma Shimiao <mashimiao.fnst@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
This reverts commit aa24163b2e.
This and the following commit led to another circular locking scenario
and the scenario which is fixed by this commit no longer exists after
e8b3f8db7a ("workqueue/hotplug: simplify workqueue_offline_cpu()")
which removes work item flushing from hotplug path.
Revert it for now.
Signed-off-by: Tejun Heo <tj@kernel.org>
This reverts commit 1599a185f0.
This and the previous commit led to another circular locking scenario
and the scenario which is fixed by this commit no longer exists after
e8b3f8db7a ("workqueue/hotplug: simplify workqueue_offline_cpu()")
which removes work item flushing from hotplug path.
Revert it for now.
Signed-off-by: Tejun Heo <tj@kernel.org>
Lockdep complains that the stats update is trying to register a non-static
key. This is because u64_stats are using a seqlock on 32bit arches, which
needs to be initialized before usage.
Fixes: 041cd640b2 (cgroup: Implement cgroup2 basic CPU usage accounting)
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
This macro `task_css_set` verifies that the caller is
inside proper critical section if the kernel set CONFIG_PROVE_RCU=y.
Signed-off-by: Wang Long <wanglong19@meituan.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Convert cpuset_hotplug_workfn() into synchronous call for cpu hotplug
path. For memory hotplug path it still gets queued as a work item.
Since cpuset_hotplug_workfn() can be made synchronous for cpu hotplug
path, it is not required to wait for cpuset hotplug while thawing
processes.
Signed-off-by: Prateek Sood <prsood@codeaurora.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Remove circular dependency deadlock in a scenario where hotplug of CPU is
being done while there is updation in cgroup and cpuset triggered from
userspace.
Process A => kthreadd => Process B => Process C => Process A
Process A
cpu_subsys_offline();
cpu_down();
_cpu_down();
percpu_down_write(&cpu_hotplug_lock); //held
cpuhp_invoke_callback();
workqueue_offline_cpu();
queue_work_on(); // unbind_work on system_highpri_wq
__queue_work();
insert_work();
wake_up_worker();
flush_work();
wait_for_completion();
worker_thread();
manage_workers();
create_worker();
kthread_create_on_node();
wake_up_process(kthreadd_task);
kthreadd
kthreadd();
kernel_thread();
do_fork();
copy_process();
percpu_down_read(&cgroup_threadgroup_rwsem);
__rwsem_down_read_failed_common(); //waiting
Process B
kernfs_fop_write();
cgroup_file_write();
cgroup_procs_write();
percpu_down_write(&cgroup_threadgroup_rwsem); //held
cgroup_attach_task();
cgroup_migrate();
cgroup_migrate_execute();
cpuset_can_attach();
mutex_lock(&cpuset_mutex); //waiting
Process C
kernfs_fop_write();
cgroup_file_write();
cpuset_write_resmask();
mutex_lock(&cpuset_mutex); //held
update_cpumask();
update_cpumasks_hier();
rebuild_sched_domains_locked();
get_online_cpus();
percpu_down_read(&cpu_hotplug_lock); //waiting
Eliminating deadlock by reversing the locking order for cpuset_mutex and
cpu_hotplug_lock.
Signed-off-by: Prateek Sood <prsood@codeaurora.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Pull cgroup updates from Tejun Heo:
"Cgroup2 cpu controller support is finally merged.
- Basic cpu statistics support to allow monitoring by default without
the CPU controller enabled.
- cgroup2 cpu controller support.
- /sys/kernel/cgroup files to help dealing with new / optional
features"
* 'for-4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup: export list of cgroups v2 features using sysfs
cgroup: export list of delegatable control files using sysfs
cgroup: mark @cgrp __maybe_unused in cpu_stat_show()
MAINTAINERS: relocate cpuset.c
cgroup, sched: Move basic cpu stats from cgroup.stat to cpu.stat
sched: Implement interface for cgroup unified hierarchy
sched: Misc preps for cgroup unified hierarchy interface
sched/cputime: Add dummy cputime_adjust() implementation for CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
cgroup: statically initialize init_css_set->dfl_cgrp
cgroup: Implement cgroup2 basic CPU usage accounting
cpuacct: Introduce cgroup_account_cputime[_field]()
sched/cputime: Expose cputime_adjust()
Pull networking updates from David Miller:
"Highlights:
1) Maintain the TCP retransmit queue using an rbtree, with 1GB
windows at 100Gb this really has become necessary. From Eric
Dumazet.
2) Multi-program support for cgroup+bpf, from Alexei Starovoitov.
3) Perform broadcast flooding in hardware in mv88e6xxx, from Andrew
Lunn.
4) Add meter action support to openvswitch, from Andy Zhou.
5) Add a data meta pointer for BPF accessible packets, from Daniel
Borkmann.
6) Namespace-ify almost all TCP sysctl knobs, from Eric Dumazet.
7) Turn on Broadcom Tags in b53 driver, from Florian Fainelli.
8) More work to move the RTNL mutex down, from Florian Westphal.
9) Add 'bpftool' utility, to help with bpf program introspection.
From Jakub Kicinski.
10) Add new 'cpumap' type for XDP_REDIRECT action, from Jesper
Dangaard Brouer.
11) Support 'blocks' of transformations in the packet scheduler which
can span multiple network devices, from Jiri Pirko.
12) TC flower offload support in cxgb4, from Kumar Sanghvi.
13) Priority based stream scheduler for SCTP, from Marcelo Ricardo
Leitner.
14) Thunderbolt networking driver, from Amir Levy and Mika Westerberg.
15) Add RED qdisc offloadability, and use it in mlxsw driver. From
Nogah Frankel.
16) eBPF based device controller for cgroup v2, from Roman Gushchin.
17) Add some fundamental tracepoints for TCP, from Song Liu.
18) Remove garbage collection from ipv6 route layer, this is a
significant accomplishment. From Wei Wang.
19) Add multicast route offload support to mlxsw, from Yotam Gigi"
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (2177 commits)
tcp: highest_sack fix
geneve: fix fill_info when link down
bpf: fix lockdep splat
net: cdc_ncm: GetNtbFormat endian fix
openvswitch: meter: fix NULL pointer dereference in ovs_meter_cmd_reply_start
netem: remove unnecessary 64 bit modulus
netem: use 64 bit divide by rate
tcp: Namespace-ify sysctl_tcp_default_congestion_control
net: Protect iterations over net::fib_notifier_ops in fib_seq_sum()
ipv6: set all.accept_dad to 0 by default
uapi: fix linux/tls.h userspace compilation error
usbnet: ipheth: prevent TX queue timeouts when device not ready
vhost_net: conditionally enable tx polling
uapi: fix linux/rxrpc.h userspace compilation errors
net: stmmac: fix LPI transitioning for dwmac4
atm: horizon: Fix irq release error
net-sysfs: trigger netlink notification on ifalias change via sysfs
openvswitch: Using kfree_rcu() to simplify the code
openvswitch: Make local function ovs_nsh_key_attr_size() static
openvswitch: Fix return value check in ovs_meter_cmd_features()
...
The active development of cgroups v2 sometimes leads to a creation
of interfaces, which are not turned on by default (to provide
backward compatibility). It's handy to know from userspace, which
cgroup v2 features are supported without calculating it based
on the kernel version. So, let's export the list of such features
using /sys/kernel/cgroup/features pseudo-file.
The list is hardcoded and has to be extended when new functionality
is added. Each feature is printed on a new line.
Example:
$ cat /sys/kernel/cgroup/features
nsdelegate
Signed-off-by: Roman Gushchin <guro@fb.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: kernel-team@fb.com
Signed-off-by: Tejun Heo <tj@kernel.org>
Delegatable cgroup v2 control files may require special handling
(e.g. chowning), and the exact list of such files varies between
kernel versions (and likely to be extended in the future).
To guarantee correctness of this list and simplify the life
of userspace (systemd, first of all), let's export the list
via /sys/kernel/cgroup/delegate pseudo-file.
Format is siple: each control file name is printed on a new line.
Example:
$ cat /sys/kernel/cgroup/delegate
cgroup.procs
cgroup.subtree_control
Signed-off-by: Roman Gushchin <guro@fb.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: kernel-team@fb.com
Signed-off-by: Tejun Heo <tj@kernel.org>
Files removed in 'net-next' had their license header updated
in 'net'. We take the remove from 'net-next'.
Signed-off-by: David S. Miller <davem@davemloft.net>
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.
By default all files without license information are under the default
license of the kernel, which is GPL version 2.
Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.
This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.
How this work was done:
Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,
Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.
The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.
The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.
Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).
All documentation files were explicitly excluded.
The following heuristics were used to determine which SPDX license
identifiers to apply.
- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.
For non */uapi/* files that summary was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139
and resulted in the first patch in this series.
If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930
and resulted in the second patch in this series.
- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:
SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1
and that resulted in the third patch in this series.
- when the two scanners agreed on the detected license(s), that became
the concluded license(s).
- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.
- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).
- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.
- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.
In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.
Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.
Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.
In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.
Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct
This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.
These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The local variable @cgrp isn't used if !CONFIG_CGROUP_SCHED. Mark the
variable with __maybe_unused to avoid a compile warning.
Reported-by: "kbuild-all@01.org" <kbuild-all@01.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
We want to centralize the isolation features, to be done by the housekeeping
subsystem and scheduler domain isolation is a significant part of it.
No intended behaviour change, we just reuse the housekeeping cpumask
and core code.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Wanpeng Li <kernellwp@gmail.com>
Link: http://lkml.kernel.org/r/1509072159-31808-11-git-send-email-frederic@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The basic cpu stat is currently shown with "cpu." prefix in
cgroup.stat, and the same information is duplicated in cpu.stat when
cpu controller is enabled. This is ugly and not very scalable as we
want to expand the coverage of stat information which is always
available.
This patch makes cgroup core always create "cpu.stat" file and show
the basic cpu stat there and calls the cpu controller to show the
extra stats when enabled. This ensures that the same information
isn't presented in multiple places and makes future expansion of basic
stats easier.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
introduce BPF_PROG_QUERY command to retrieve a set of either
attached programs to given cgroup or a set of effective programs
that will execute for events within a cgroup
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
for cgroup bits
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
introduce BPF_F_ALLOW_MULTI flag that can be used to attach multiple
bpf programs to a cgroup.
The difference between three possible flags for BPF_PROG_ATTACH command:
- NONE(default): No further bpf programs allowed in the subtree.
- BPF_F_ALLOW_OVERRIDE: If a sub-cgroup installs some bpf program,
the program in this cgroup yields to sub-cgroup program.
- BPF_F_ALLOW_MULTI: If a sub-cgroup installs some bpf program,
that cgroup program gets run in addition to the program in this cgroup.
NONE and BPF_F_ALLOW_OVERRIDE existed before. This patch doesn't
change their behavior. It only clarifies the semantics in relation
to new flag.
Only one program is allowed to be attached to a cgroup with
NONE or BPF_F_ALLOW_OVERRIDE flag.
Multiple programs are allowed to be attached to a cgroup with
BPF_F_ALLOW_MULTI flag. They are executed in FIFO order
(those that were attached first, run first)
The programs of sub-cgroup are executed first, then programs of
this cgroup and then programs of parent cgroup.
All eligible programs are executed regardless of return code from
earlier programs.
To allow efficient execution of multiple programs attached to a cgroup
and to avoid penalizing cgroups without any programs attached
introduce 'struct bpf_prog_array' which is RCU protected array
of pointers to bpf programs.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
for cgroup bits
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
In cgroup1, while cpuacct isn't actually controlling any resources, it
is a separate controller due to combination of two factors -
1. enabling cpu controller has significant side effects, and 2. we
have to pick one of the hierarchies to account CPU usages on. cpuacct
controller is effectively used to designate a hierarchy to track CPU
usages on.
cgroup2's unified hierarchy removes the second reason and we can
account basic CPU usages by default. While we can use cpuacct for
this purpose, both its interface and implementation leave a lot to be
desired - it collects and exposes two sources of truth which don't
agree with each other and some of the exposed statistics don't make
much sense. Also, it propagates all the way up the hierarchy on each
accounting event which is unnecessary.
This patch adds basic resource accounting mechanism to cgroup2's
unified hierarchy and accounts CPU usages using it.
* All accountings are done per-cpu and don't propagate immediately.
It just bumps the per-cgroup per-cpu counters and links to the
parent's updated list if not already on it.
* On a read, the per-cpu counters are collected into the global ones
and then propagated upwards. Only the per-cpu counters which have
changed since the last read are propagated.
* CPU usage stats are collected and shown in "cgroup.stat" with "cpu."
prefix. Total usage is collected from scheduling events. User/sys
breakdown is sourced from tick sampling and adjusted to the usage
using cputime_adjust().
This keeps the accounting side hot path O(1) and per-cpu and the read
side O(nr_updated_since_last_read).
v2: Minor changes and documentation updates as suggested by Waiman and
Roman.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Waiman Long <longman@redhat.com>
Cc: Roman Gushchin <guro@fb.com>
The cgroup_taskset structure within the larger cgroup_mgctx structure
is supposed to be used once and then discarded. That is not really the
case in the hotplug code path:
cpuset_hotplug_workfn()
- cgroup_transfer_tasks()
- cgroup_migrate()
- cgroup_migrate_add_task()
- cgroup_migrate_execute()
In this case, the cgroup_migrate() function is called multiple time
with the same cgroup_mgctx structure to transfer the tasks from
one cgroup to another one-by-one. The second time cgroup_migrate()
is called, the cgroup_taskset will be in an incorrect state and so
may cause the system to panic. For example,
[ 150.888410] Faulting instruction address: 0xc0000000001db648
[ 150.888414] Oops: Kernel access of bad area, sig: 11 [#1]
[ 150.888417] SMP NR_CPUS=2048
[ 150.888417] NUMA
[ 150.888419] pSeries
:
[ 150.888545] NIP [c0000000001db648] cpuset_can_attach+0x58/0x1b0
[ 150.888548] LR [c0000000001db638] cpuset_can_attach+0x48/0x1b0
[ 150.888551] Call Trace:
[ 150.888554] [c0000005f65cb940] [c0000000001db638] cpuset_can_attach+0x48/0x1b 0 (unreliable)
[ 150.888559] [c0000005f65cb9a0] [c0000000001cff04] cgroup_migrate_execute+0xc4/0x4b0
[ 150.888563] [c0000005f65cba20] [c0000000001d7d14] cgroup_transfer_tasks+0x1d4/0x370
[ 150.888568] [c0000005f65cbb70] [c0000000001ddcb0] cpuset_hotplug_workfn+0x710/0x8f0
[ 150.888572] [c0000005f65cbc80] [c00000000012032c] process_one_work+0x1ac/0x4d0
[ 150.888576] [c0000005f65cbd20] [c0000000001206f8] worker_thread+0xa8/0x5b0
[ 150.888580] [c0000005f65cbdc0] [c0000000001293f8] kthread+0x168/0x1b0
[ 150.888584] [c0000005f65cbe30] [c00000000000b368] ret_from_kernel_thread+0x5c/0x74
To allow reuse of the cgroup_mgctx structure, some fields in that
structure are now re-initialized at the end of cgroup_migrate_execute()
function call so that the structure can be reused again in a later
iteration without causing problem.
This bug was introduced in the commit e595cd7069 ("group: track
migration context in cgroup_mgctx") in 4.11. This commit moves the
cgroup_taskset initialization out of cgroup_migrate(). The commit
10467270fb3 ("cgroup: don't call migration methods if there are no
tasks to migrate") helped, but did not completely resolve the problem.
Fixes: e595cd7069 ("group: track migration context in cgroup_mgctx")
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org # v4.11+
Pull block layer updates from Jens Axboe:
"This is the first pull request for 4.14, containing most of the code
changes. It's a quiet series this round, which I think we needed after
the churn of the last few series. This contains:
- Fix for a registration race in loop, from Anton Volkov.
- Overflow complaint fix from Arnd for DAC960.
- Series of drbd changes from the usual suspects.
- Conversion of the stec/skd driver to blk-mq. From Bart.
- A few BFQ improvements/fixes from Paolo.
- CFQ improvement from Ritesh, allowing idling for group idle.
- A few fixes found by Dan's smatch, courtesy of Dan.
- A warning fixup for a race between changing the IO scheduler and
device remova. From David Jeffery.
- A few nbd fixes from Josef.
- Support for cgroup info in blktrace, from Shaohua.
- Also from Shaohua, new features in the null_blk driver to allow it
to actually hold data, among other things.
- Various corner cases and error handling fixes from Weiping Zhang.
- Improvements to the IO stats tracking for blk-mq from me. Can
drastically improve performance for fast devices and/or big
machines.
- Series from Christoph removing bi_bdev as being needed for IO
submission, in preparation for nvme multipathing code.
- Series from Bart, including various cleanups and fixes for switch
fall through case complaints"
* 'for-4.14/block' of git://git.kernel.dk/linux-block: (162 commits)
kernfs: checking for IS_ERR() instead of NULL
drbd: remove BIOSET_NEED_RESCUER flag from drbd_{md_,}io_bio_set
drbd: Fix allyesconfig build, fix recent commit
drbd: switch from kmalloc() to kmalloc_array()
drbd: abort drbd_start_resync if there is no connection
drbd: move global variables to drbd namespace and make some static
drbd: rename "usermode_helper" to "drbd_usermode_helper"
drbd: fix race between handshake and admin disconnect/down
drbd: fix potential deadlock when trying to detach during handshake
drbd: A single dot should be put into a sequence.
drbd: fix rmmod cleanup, remove _all_ debugfs entries
drbd: Use setup_timer() instead of init_timer() to simplify the code.
drbd: fix potential get_ldev/put_ldev refcount imbalance during attach
drbd: new disk-option disable-write-same
drbd: Fix resource role for newly created resources in events2
drbd: mark symbols static where possible
drbd: Send P_NEG_ACK upon write error in protocol != C
drbd: add explicit plugging when submitting batches
drbd: change list_for_each_safe to while(list_first_entry_or_null)
drbd: introduce drbd_recv_header_maybe_unplug
...
Cpusets vs. suspend-resume is _completely_ broken. And it got noticed
because it now resulted in non-cpuset usage breaking too.
On suspend cpuset_cpu_inactive() doesn't call into
cpuset_update_active_cpus() because it doesn't want to move tasks about,
there is no need, all tasks are frozen and won't run again until after
we've resumed everything.
But this means that when we finally do call into
cpuset_update_active_cpus() after resuming the last frozen cpu in
cpuset_cpu_active(), the top_cpuset will not have any difference with
the cpu_active_mask and this it will not in fact do _anything_.
So the cpuset configuration will not be restored. This was largely
hidden because we would unconditionally create identity domains and
mobile users would not in fact use cpusets much. And servers what do use
cpusets tend to not suspend-resume much.
An addition problem is that we'd not in fact wait for the cpuset work to
finish before resuming the tasks, allowing spurious migrations outside
of the specified domains.
Fix the rebuild by introducing cpuset_force_rebuild() and fix the
ordering with cpuset_wait_for_hotplug().
Reported-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: deb7aa308e ("cpuset: reorganize CPU / memory hotplug handling")
Link: http://lkml.kernel.org/r/20170907091338.orwxrqkbfkki3c24@hirez.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull cgroup updates from Tejun Heo:
"Several notable changes this cycle:
- Thread mode was merged. This will be used for cgroup2 support for
CPU and possibly other controllers. Unfortunately, CPU controller
cgroup2 support didn't make this pull request but most contentions
have been resolved and the support is likely to be merged before
the next merge window.
- cgroup.stat now shows the number of descendant cgroups.
- cpuset now can enable the easier-to-configure v2 behavior on v1
hierarchy"
* 'for-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (21 commits)
cpuset: Allow v2 behavior in v1 cgroup
cgroup: Add mount flag to enable cpuset to use v2 behavior in v1 cgroup
cgroup: remove unneeded checks
cgroup: misc changes
cgroup: short-circuit cset_cgroup_from_root() on the default hierarchy
cgroup: re-use the parent pointer in cgroup_destroy_locked()
cgroup: add cgroup.stat interface with basic hierarchy stats
cgroup: implement hierarchy limits
cgroup: keep track of number of descent cgroups
cgroup: add comment to cgroup_enable_threaded()
cgroup: remove unnecessary empty check when enabling threaded mode
cgroup: update debug controller to print out thread mode information
cgroup: implement cgroup v2 thread support
cgroup: implement CSS_TASK_ITER_THREADED
cgroup: introduce cgroup->dom_cgrp and threaded css_set handling
cgroup: add @flags to css_task_iter_start() and implement CSS_TASK_ITER_PROCS
cgroup: reorganize cgroup.procs / task write path
cgroup: replace css_set walking populated test with testing cgrp->nr_populated_csets
cgroup: distinguish local and children populated states
cgroup: remove now unused list_head @pending in cgroup_apply_cftypes()
...
TIF_MEMDIE is set only to the tasks whick were either directly selected
by the OOM killer or passed through mark_oom_victim from the allocator
path. tsk_is_oom_victim is more generic and allows to identify all
tasks (threads) which share the mm with the oom victim.
Please note that the freezer still needs to check TIF_MEMDIE because we
cannot thaw tasks which do not participage in oom_victims counting
otherwise a !TIF_MEMDIE task could interfere after oom_disbale returns.
Link: http://lkml.kernel.org/r/20170810075019.28998-3-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: David Rientjes <rientjes@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit fa06235b8e ("cgroup: reset css on destruction") caused
css_reset callback to be called from the offlining path. Although it
solves the problem mentioned in the commit description ("For instance,
memory cgroup needs to reset memory.low, otherwise pages charged to a
dead cgroup might never get reclaimed."), generally speaking, it's not
correct.
An offline cgroup can still be a resource domain, and we shouldn't grant
it more resources than it had before deletion.
For instance, if an offline memory cgroup has dirty pages, we should
still imply i/o limits during writeback.
The css_reset callback is designed to return the cgroup state into the
original state, that means reset all limits and counters. It's
spomething different from the offlining, and we shouldn't use it from
the offlining path. Instead, we should adjust necessary settings from
the per-controller css_offline callbacks (e.g. reset memory.low).
Link: http://lkml.kernel.org/r/20170727130428.28856-2-guro@fb.com
Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull locking updates from Ingo Molnar:
- Add 'cross-release' support to lockdep, which allows APIs like
completions, where it's not the 'owner' who releases the lock, to be
tracked. It's all activated automatically under
CONFIG_PROVE_LOCKING=y.
- Clean up (restructure) the x86 atomics op implementation to be more
readable, in preparation of KASAN annotations. (Dmitry Vyukov)
- Fix static keys (Paolo Bonzini)
- Add killable versions of down_read() et al (Kirill Tkhai)
- Rework and fix jump_label locking (Marc Zyngier, Paolo Bonzini)
- Rework (and fix) tlb_flush_pending() barriers (Peter Zijlstra)
- Remove smp_mb__before_spinlock() and convert its usages, introduce
smp_mb__after_spinlock() (Peter Zijlstra)
* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (56 commits)
locking/lockdep/selftests: Fix mixed read-write ABBA tests
sched/completion: Avoid unnecessary stack allocation for COMPLETION_INITIALIZER_ONSTACK()
acpi/nfit: Fix COMPLETION_INITIALIZER_ONSTACK() abuse
locking/pvqspinlock: Relax cmpxchg's to improve performance on some architectures
smp: Avoid using two cache lines for struct call_single_data
locking/lockdep: Untangle xhlock history save/restore from task independence
locking/refcounts, x86/asm: Disable CONFIG_ARCH_HAS_REFCOUNT for the time being
futex: Remove duplicated code and fix undefined behaviour
Documentation/locking/atomic: Finish the document...
locking/lockdep: Fix workqueue crossrelease annotation
workqueue/lockdep: 'Fix' flush_work() annotation
locking/lockdep/selftests: Add mixed read-write ABBA tests
mm, locking/barriers: Clarify tlb_flush_pending() barriers
locking/lockdep: Make CONFIG_LOCKDEP_CROSSRELEASE and CONFIG_LOCKDEP_COMPLETIONS truly non-interactive
locking/lockdep: Explicitly initialize wq_barrier::done::map
locking/lockdep: Rename CONFIG_LOCKDEP_COMPLETE to CONFIG_LOCKDEP_COMPLETIONS
locking/lockdep: Reword title of LOCKDEP_CROSSRELEASE config
locking/lockdep: Make CONFIG_LOCKDEP_CROSSRELEASE part of CONFIG_PROVE_LOCKING
locking/refcounts, x86/asm: Implement fast refcount overflow protection
locking/lockdep: Fix the rollback and overwrite detection logic in crossrelease
...
Pull scheduler updates from Ingo Molnar:
"The main changes in this cycle were:
- fix affine wakeups (Peter Zijlstra)
- improve CPU onlining (and general bootup) scalability on systems
with ridiculous number (thousands) of CPUs (Peter Zijlstra)
- sched/numa updates (Rik van Riel)
- sched/deadline updates (Byungchul Park)
- sched/cpufreq enhancements and related cleanups (Viresh Kumar)
- sched/debug enhancements (Xie XiuQi)
- various fixes"
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (27 commits)
sched/debug: Optimize sched_domain sysctl generation
sched/topology: Avoid pointless rebuild
sched/topology, cpuset: Avoid spurious/wrong domain rebuilds
sched/topology: Improve comments
sched/topology: Fix memory leak in __sdt_alloc()
sched/completion: Document that reinit_completion() must be called after complete_all()
sched/autogroup: Fix error reporting printk text in autogroup_create()
sched/fair: Fix wake_affine() for !NUMA_BALANCING
sched/debug: Intruduce task_state_to_char() helper function
sched/debug: Show task state in /proc/sched_debug
sched/debug: Use task_pid_nr_ns in /proc/$pid/sched
sched/core: Remove unnecessary initialization init_idle_bootup_task()
sched/deadline: Change return value of cpudl_find()
sched/deadline: Make find_later_rq() choose a closer CPU in topology
sched/numa: Scale scan period with tasks in group and shared/private
sched/numa: Slow down scan rate if shared faults dominate
sched/pelt: Fix false running accounting
sched: Mark pick_next_task_dl() and build_sched_domain() as static
sched/cpupri: Don't re-initialize 'struct cpupri'
sched/deadline: Don't re-initialize 'struct cpudl'
...
Pull cgroup fix from Tejun Heo:
"A late but obvious fix for cgroup.
I broke the 'cpuset.memory_pressure' file a long time ago (v4.4) by
accidentally deleting its file index, which made it a duplicate of the
'cpuset.memory_migrate' file. Spotted and fixed by Waiman"
* 'for-4.13-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cpuset: Fix incorrect memory_pressure control file mapping
When disabling cpuset.sched_load_balance we expect to be able to online
CPUs without generating sched_domains. However this is currently
completely broken.
What happens is that we generate the sched_domains and then destroy
them. This is because of the spurious 'default' domain build in
cpuset_update_active_cpus(). That builds a single machine wide domain
and then schedules a work to build the 'real' domains. The work then
finds there are _no_ domains and destroys the lot again.
Furthermore, if there actually were cpusets, building the machine wide
domain is actively wrong, because it would allow tasks to 'escape' their
cpuset. Also I don't think its needed, the scheduler really should
respect the active mask.
Reported-by: Ofer Levi(SW) <oferle@mellanox.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vineet.Gupta1@synopsys.com <Vineet.Gupta1@synopsys.com>
Cc: rusty@rustcorp.com.au <rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The memory_pressure control file was incorrectly set up without
a private value (0, by default). As a result, this control
file was treated like memory_migrate on read. By adding back the
FILE_MEMORY_PRESSURE private value, the correct memory pressure value
will be returned.
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Fixes: 7dbdb199d3 ("cgroup: replace cftype->mode with CFTYPE_WORLD_WRITABLE")
Cc: stable@vger.kernel.org # v4.4+
Cpuset v2 has some useful behaviors that are not present in v1 because
of backward compatibility concern. One of that is the restoration of
the original cpu and memory node mask after a hot removal and addition
event sequence.
This patch makes the cpuset controller to check the
CGRP_ROOT_CPUSET_V2_MODE flag and use the v2 behavior if it is set.
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
A new mount option "cpuset_v2_mode" is added to the v1 cgroupfs
filesystem to enable cpuset controller to use v2 behavior in a v1
cgroup. This mount option applies only to cpuset controller and have
no effect on other controllers.
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Linus Torvalds
yuzhoujian
Tejun Heo
Ondrej Mosnacek
Dennis Zhou
YueHaibing
Paul E. McKenney
Waiman Long
Yangtao Li
Johannes Weiner
Dennis Zhou (Facebook)
Dmitry Torokhov
Steven Rostedt (VMware)
Mauro Carvalho Chehab
Kees Cook
Christoph Hellwig
Andy Shevchenko
Yaowei Bai
Roman Gushchin
Prateek Sood
Arnd Bergmann
Ma Shimiao
Lucas Stach
Wang Long
Ingo Molnar
David S. Miller
Greg Kroah-Hartman
Frederic Weisbecker
Alexei Starovoitov
Peter Zijlstra
Michal Hocko