Commit Graph

429946 Commits

Author SHA1 Message Date
Daniel Borkmann c5c2f8986e netlink: reset network header before passing to taps
[ Upstream commit 4e48ed883c ]

netlink doesn't set any network header offset thus when the skb is
being passed to tap devices via dev_queue_xmit_nit(), it emits klog
false positives due to it being unset like:

  ...
  [  124.990397] protocol 0000 is buggy, dev nlmon0
  [  124.990411] protocol 0000 is buggy, dev nlmon0
  ...

So just reset the network header before passing to the device; for
packet sockets that just means nothing will change - mac and net
offset hold the same value just as before.

Reported-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-15 08:36:40 +02:00
Greg Kroah-Hartman 89161fe91f Linux 3.14.21 2014-10-09 12:21:39 -07:00
Linus Torvalds c56af023a5 mm: don't pointlessly use BUG_ON() for sanity check
commit 50f5aa8a9b upstream.

BUG_ON() is a big hammer, and should be used _only_ if there is some
major corruption that you cannot possibly recover from, making it
imperative that the current process (and possibly the whole machine) be
terminated with extreme prejudice.

The trivial sanity check in the vmacache code is *not* such a fatal
error.  Recovering from it is absolutely trivial, and using BUG_ON()
just makes it harder to debug for no actual advantage.

To make matters worse, the placement of the BUG_ON() (only if the range
check matched) actually makes it harder to hit the sanity check to begin
with, so _if_ there is a bug (and we just got a report from Srivatsa
Bhat that this can indeed trigger), it is harder to debug not just
because the machine is possibly dead, but because we don't have better
coverage.

BUG_ON() must *die*.  Maybe we should add a checkpatch warning for it,
because it is simply just about the worst thing you can ever do if you
hit some "this cannot happen" situation.

Reported-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Davidlohr Bueso <davidlohr@hp.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-09 12:21:29 -07:00
Davidlohr Bueso efb5fea230 mm: per-thread vma caching
commit 615d6e8756 upstream.

This patch is a continuation of efforts trying to optimize find_vma(),
avoiding potentially expensive rbtree walks to locate a vma upon faults.
The original approach (https://lkml.org/lkml/2013/11/1/410), where the
largest vma was also cached, ended up being too specific and random,
thus further comparison with other approaches were needed.  There are
two things to consider when dealing with this, the cache hit rate and
the latency of find_vma().  Improving the hit-rate does not necessarily
translate in finding the vma any faster, as the overhead of any fancy
caching schemes can be too high to consider.

We currently cache the last used vma for the whole address space, which
provides a nice optimization, reducing the total cycles in find_vma() by
up to 250%, for workloads with good locality.  On the other hand, this
simple scheme is pretty much useless for workloads with poor locality.
Analyzing ebizzy runs shows that, no matter how many threads are
running, the mmap_cache hit rate is less than 2%, and in many situations
below 1%.

The proposed approach is to replace this scheme with a small per-thread
cache, maximizing hit rates at a very low maintenance cost.
Invalidations are performed by simply bumping up a 32-bit sequence
number.  The only expensive operation is in the rare case of a seq
number overflow, where all caches that share the same address space are
flushed.  Upon a miss, the proposed replacement policy is based on the
page number that contains the virtual address in question.  Concretely,
the following results are seen on an 80 core, 8 socket x86-64 box:

1) System bootup: Most programs are single threaded, so the per-thread
   scheme does improve ~50% hit rate by just adding a few more slots to
   the cache.

+----------------+----------+------------------+
| caching scheme | hit-rate | cycles (billion) |
+----------------+----------+------------------+
| baseline       | 50.61%   | 19.90            |
| patched        | 73.45%   | 13.58            |
+----------------+----------+------------------+

2) Kernel build: This one is already pretty good with the current
   approach as we're dealing with good locality.

+----------------+----------+------------------+
| caching scheme | hit-rate | cycles (billion) |
+----------------+----------+------------------+
| baseline       | 75.28%   | 11.03            |
| patched        | 88.09%   | 9.31             |
+----------------+----------+------------------+

3) Oracle 11g Data Mining (4k pages): Similar to the kernel build workload.

+----------------+----------+------------------+
| caching scheme | hit-rate | cycles (billion) |
+----------------+----------+------------------+
| baseline       | 70.66%   | 17.14            |
| patched        | 91.15%   | 12.57            |
+----------------+----------+------------------+

4) Ebizzy: There's a fair amount of variation from run to run, but this
   approach always shows nearly perfect hit rates, while baseline is just
   about non-existent.  The amounts of cycles can fluctuate between
   anywhere from ~60 to ~116 for the baseline scheme, but this approach
   reduces it considerably.  For instance, with 80 threads:

+----------------+----------+------------------+
| caching scheme | hit-rate | cycles (billion) |
+----------------+----------+------------------+
| baseline       | 1.06%    | 91.54            |
| patched        | 99.97%   | 14.18            |
+----------------+----------+------------------+

[akpm@linux-foundation.org: fix nommu build, per Davidlohr]
[akpm@linux-foundation.org: document vmacache_valid() logic]
[akpm@linux-foundation.org: attempt to untangle header files]
[akpm@linux-foundation.org: add vmacache_find() BUG_ON]
[hughd@google.com: add vmacache_valid_mm() (from Oleg)]
[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: adjust and enhance comments]
Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Michel Lespinasse <walken@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Tested-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-09 12:21:29 -07:00
Christoph Lameter 264a8ae739 vmscan: reclaim_clean_pages_from_list() must use mod_zone_page_state()
commit 83da751005 upstream.

Seems to be called with preemption enabled.  Therefore it must use
mod_zone_page_state instead.

Signed-off-by: Christoph Lameter <cl@linux.com>
Reported-by: Grygorii Strashko <grygorii.strashko@ti.com>
Tested-by: Grygorii Strashko <grygorii.strashko@ti.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-09 12:21:29 -07:00
Vladimir Davydov 8e524793fd mm: vmscan: shrink_slab: rename max_pass -> freeable
commit d5bc5fd3fc upstream.

The name `max_pass' is misleading, because this variable actually keeps
the estimate number of freeable objects, not the maximal number of
objects we can scan in this pass, which can be twice that.  Rename it to
reflect its actual meaning.

Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-09 12:21:29 -07:00
Vladimir Davydov 12f2f0bab4 mm: vmscan: respect NUMA policy mask when shrinking slab on direct reclaim
commit 99120b772b upstream.

When direct reclaim is executed by a process bound to a set of NUMA
nodes, we should scan only those nodes when possible, but currently we
will scan kmem from all online nodes even if the kmem shrinker is NUMA
aware.  That said, binding a process to a particular NUMA node won't
prevent it from shrinking inode/dentry caches from other nodes, which is
not good.  Fix this.

Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Glauber Costa <glommer@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-09 12:21:29 -07:00
Jens Axboe 6591981a30 mm/filemap.c: avoid always dirtying mapping->flags on O_DIRECT
commit 7fcbbaf183 upstream.

In some testing I ran today (some fio jobs that spread over two nodes),
we end up spending 40% of the time in filemap_check_errors().  That
smells fishy.  Looking further, this is basically what happens:

blkdev_aio_read()
    generic_file_aio_read()
        filemap_write_and_wait_range()
            if (!mapping->nr_pages)
                filemap_check_errors()

and filemap_check_errors() always attempts two test_and_clear_bit() on
the mapping flags, thus dirtying it for every single invocation.  The
patch below tests each of these bits before clearing them, avoiding this
issue.  In my test case (4-socket box), performance went from 1.7M IOPS
to 4.0M IOPS.

Signed-off-by: Jens Axboe <axboe@fb.com>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-09 12:21:29 -07:00
Mel Gorman 29c2a88157 mm: optimize put_mems_allowed() usage
commit d26914d117 upstream.

Since put_mems_allowed() is strictly optional, its a seqcount retry, we
don't need to evaluate the function if the allocation was in fact
successful, saving a smp_rmb some loads and comparisons on some relative
fast-paths.

Since the naming, get/put_mems_allowed() does suggest a mandatory
pairing, rename the interface, as suggested by Mel, to resemble the
seqcount interface.

This gives us: read_mems_allowed_begin() and read_mems_allowed_retry(),
where it is important to note that the return value of the latter call
is inverted from its previous incarnation.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-09 12:21:28 -07:00
Raghavendra K T d4995db1ea mm/readahead.c: fix readahead failure for memoryless NUMA nodes and limit readahead pages
commit 6d2be915e5 upstream.

Currently max_sane_readahead() returns zero on the cpu whose NUMA node
has no local memory which leads to readahead failure.  Fix this
readahead failure by returning minimum of (requested pages, 512).  Users
running applications on a memory-less cpu which needs readahead such as
streaming application see considerable boost in the performance.

Result:

fadvise experiment with FADV_WILLNEED on a PPC machine having memoryless
CPU with 1GB testfile (12 iterations) yielded around 46.66% improvement.

fadvise experiment with FADV_WILLNEED on a x240 machine with 1GB
testfile 32GB* 4G RAM numa machine (12 iterations) showed no impact on
the normal NUMA cases w/ patch.

  Kernel       Avg  Stddev
  base      7.4975   3.92%
  patched   7.4174   3.26%

[Andrew: making return value PAGE_SIZE independent]
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Acked-by: Jan Kara <jack@suse.cz>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-09 12:21:28 -07:00
David Rientjes 67c58ce600 mm, compaction: ignore pageblock skip when manually invoking compaction
commit 91ca918648 upstream.

The cached pageblock hint should be ignored when triggering compaction
through /proc/sys/vm/compact_memory so all eligible memory is isolated.
Manually invoking compaction is known to be expensive, there's no need
to skip pageblocks based on heuristics (mainly for debugging).

Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-09 12:21:28 -07:00
David Rientjes e8cd5b562a mm, compaction: determine isolation mode only once
commit da1c67a76f upstream.

The conditions that control the isolation mode in
isolate_migratepages_range() do not change during the iteration, so
extract them out and only define the value once.

This actually does have an effect, gcc doesn't optimize it itself because
of cc->sync.

Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-09 12:21:28 -07:00
Joonsoo Kim ca82ea2e65 mm/compaction: clean-up code on success of ballon isolation
commit b6c750163c upstream.

It is just for clean-up to reduce code size and improve readability.
There is no functional change.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-09 12:21:28 -07:00
Joonsoo Kim 6128cc0567 mm/compaction: check pageblock suitability once per pageblock
commit c122b2087a upstream.

isolation_suitable() and migrate_async_suitable() is used to be sure
that this pageblock range is fine to be migragted.  It isn't needed to
call it on every page.  Current code do well if not suitable, but, don't
do well when suitable.

1) It re-checks isolation_suitable() on each page of a pageblock that was
   already estabilished as suitable.
2) It re-checks migrate_async_suitable() on each page of a pageblock that
   was not entered through the next_pageblock: label, because
   last_pageblock_nr is not otherwise updated.

This patch fixes situation by 1) calling isolation_suitable() only once
per pageblock and 2) always updating last_pageblock_nr to the pageblock
that was just checked.

Additionally, move PageBuddy() check after pageblock unit check, since
pageblock check is the first thing we should do and makes things more
simple.

[vbabka@suse.cz: rephrase commit description]
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-09 12:21:28 -07:00
Joonsoo Kim 4fff5ca780 mm/compaction: change the timing to check to drop the spinlock
commit be1aa03b97 upstream.

It is odd to drop the spinlock when we scan (SWAP_CLUSTER_MAX - 1) th
pfn page.  This may results in below situation while isolating
migratepage.

1. try isolate 0x0 ~ 0x200 pfn pages.
2. When low_pfn is 0x1ff, ((low_pfn+1) % SWAP_CLUSTER_MAX) == 0, so drop
   the spinlock.
3. Then, to complete isolating, retry to aquire the lock.

I think that it is better to use SWAP_CLUSTER_MAX th pfn for checking the
criteria about dropping the lock.  This has no harm 0x0 pfn, because, at
this time, locked variable would be false.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-09 12:21:28 -07:00
Lars Ellenberg cc85d67f4f drbd: fix regression 'out of mem, failed to invoke fence-peer helper'
commit bbc1c5e8ad upstream.

Since linux kernel 3.13, kthread_run() internally uses
wait_for_completion_killable().  We sometimes may use kthread_run()
while we still have a signal pending, which we used to kick our threads
out of potentially blocking network functions, causing kthread_run() to
mistake that as a new fatal signal and fail.

Fix: flush_signals() before kthread_run().

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-09 12:21:28 -07:00
Joonsoo Kim e292d9ad60 mm/compaction: do not call suitable_migration_target() on every page
commit 01ead5340b upstream.

suitable_migration_target() checks that pageblock is suitable for
migration target.  In isolate_freepages_block(), it is called on every
page and this is inefficient.  So make it called once per pageblock.

suitable_migration_target() also checks if page is highorder or not, but
it's criteria for highorder is pageblock order.  So calling it once
within pageblock range has no problem.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-09 12:21:28 -07:00
Joonsoo Kim 96b3fde44d mm/compaction: disallow high-order page for migration target
commit 7d348b9ea6 upstream.

Purpose of compaction is to get a high order page.  Currently, if we
find high-order page while searching migration target page, we break it
to order-0 pages and use them as migration target.  It is contrary to
purpose of compaction, so disallow high-order page to be used for
migration target.

Additionally, clean-up logic in suitable_migration_target() to simplify
the code.  There is no functional changes from this clean-up.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-09 12:21:28 -07:00
David Rientjes 1190e5c69c mm, compaction: avoid isolating pinned pages
commit 119d6d59dc upstream.

Page migration will fail for memory that is pinned in memory with, for
example, get_user_pages().  In this case, it is unnecessary to take
zone->lru_lock or isolating the page and passing it to page migration
which will ultimately fail.

This is a racy check, the page can still change from under us, but in
that case we'll just fail later when attempting to move the page.

This avoids very expensive memory compaction when faulting transparent
hugepages after pinning a lot of memory with a Mellanox driver.

On a 128GB machine and pinning ~120GB of memory, before this patch we
see the enormous disparity in the number of page migration failures
because of the pinning (from /proc/vmstat):

	compact_pages_moved 8450
	compact_pagemigrate_failed 15614415

0.05% of pages isolated are successfully migrated and explicitly
triggering memory compaction takes 102 seconds.  After the patch:

	compact_pages_moved 9197
	compact_pagemigrate_failed 7

99.9% of pages isolated are now successfully migrated in this
configuration and memory compaction takes less than one second.

Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-09 12:21:28 -07:00
Dan Streetman d540b16890 swap: change swap_list_head to plist, add swap_avail_head
commit 18ab4d4ced upstream.

Originally get_swap_page() started iterating through the singly-linked
list of swap_info_structs using swap_list.next or highest_priority_index,
which both were intended to point to the highest priority active swap
target that was not full.  The first patch in this series changed the
singly-linked list to a doubly-linked list, and removed the logic to start
at the highest priority non-full entry; it starts scanning at the highest
priority entry each time, even if the entry is full.

Replace the manually ordered swap_list_head with a plist, swap_active_head.
Add a new plist, swap_avail_head.  The original swap_active_head plist
contains all active swap_info_structs, as before, while the new
swap_avail_head plist contains only swap_info_structs that are active and
available, i.e. not full.  Add a new spinlock, swap_avail_lock, to protect
the swap_avail_head list.

Mel Gorman suggested using plists since they internally handle ordering
the list entries based on priority, which is exactly what swap was doing
manually.  All the ordering code is now removed, and swap_info_struct
entries and simply added to their corresponding plist and automatically
ordered correctly.

Using a new plist for available swap_info_structs simplifies and
optimizes get_swap_page(), which no longer has to iterate over full
swap_info_structs.  Using a new spinlock for swap_avail_head plist
allows each swap_info_struct to add or remove themselves from the
plist when they become full or not-full; previously they could not
do so because the swap_info_struct->lock is held when they change
from full<->not-full, and the swap_lock protecting the main
swap_active_head must be ordered before any swap_info_struct->lock.

Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Shaohua Li <shli@fusionio.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
Cc: Weijie Yang <weijieut@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Bob Liu <bob.liu@oracle.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-09 12:21:28 -07:00
Dan Streetman ae604916e2 lib/plist: add plist_requeue
commit a75f232ce0 upstream.

Add plist_requeue(), which moves the specified plist_node after all other
same-priority plist_nodes in the list.  This is essentially an optimized
plist_del() followed by plist_add().

This is needed by swap, which (with the next patch in this set) uses a
plist of available swap devices.  When a swap device (either a swap
partition or swap file) are added to the system with swapon(), the device
is added to a plist, ordered by the swap device's priority.  When swap
needs to allocate a page from one of the swap devices, it takes the page
from the first swap device on the plist, which is the highest priority
swap device.  The swap device is left in the plist until all its pages are
used, and then removed from the plist when it becomes full.

However, as described in man 2 swapon, swap must allocate pages from swap
devices with the same priority in round-robin order; to do this, on each
swap page allocation, swap uses a page from the first swap device in the
plist, and then calls plist_requeue() to move that swap device entry to
after any other same-priority swap devices.  The next swap page allocation
will again use a page from the first swap device in the plist and requeue
it, and so on, resulting in round-robin usage of equal-priority swap
devices.

Also add plist_test_requeue() test function, for use by plist_test() to
test plist_requeue() function.

Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Shaohua Li <shli@fusionio.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
Cc: Weijie Yang <weijieut@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Bob Liu <bob.liu@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-09 12:21:27 -07:00
Dan Streetman fd6d61cc8a lib/plist: add helper functions
commit fd16618e12 upstream.

Add PLIST_HEAD() to plist.h, equivalent to LIST_HEAD() from list.h, to
define and initialize a struct plist_head.

Add plist_for_each_continue() and plist_for_each_entry_continue(),
equivalent to list_for_each_continue() and list_for_each_entry_continue(),
to iterate over a plist continuing after the current position.

Add plist_prev() and plist_next(), equivalent to (struct list_head*)->prev
and ->next, implemented by list_prev_entry() and list_next_entry(), to
access the prev/next struct plist_node entry.  These are needed because
unlike struct list_head, direct access of the prev/next struct plist_node
isn't possible; the list must be navigated via the contained struct
list_head.  e.g.  instead of accessing the prev by list_prev_entry(node,
node_list) it can be accessed by plist_prev(node).

Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Shaohua Li <shli@fusionio.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
Cc: Weijie Yang <weijieut@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Bob Liu <bob.liu@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-09 12:21:27 -07:00
Dan Streetman bcbfe6fdf8 swap: change swap_info singly-linked list to list_head
commit adfab836f4 upstream.

The logic controlling the singly-linked list of swap_info_struct entries
for all active, i.e.  swapon'ed, swap targets is rather complex, because:

 - it stores the entries in priority order
 - there is a pointer to the highest priority entry
 - there is a pointer to the highest priority not-full entry
 - there is a highest_priority_index variable set outside the swap_lock
 - swap entries of equal priority should be used equally

this complexity leads to bugs such as: https://lkml.org/lkml/2014/2/13/181
where different priority swap targets are incorrectly used equally.

That bug probably could be solved with the existing singly-linked lists,
but I think it would only add more complexity to the already difficult to
understand get_swap_page() swap_list iteration logic.

The first patch changes from a singly-linked list to a doubly-linked list
using list_heads; the highest_priority_index and related code are removed
and get_swap_page() starts each iteration at the highest priority
swap_info entry, even if it's full.  While this does introduce unnecessary
list iteration (i.e.  Schlemiel the painter's algorithm) in the case where
one or more of the highest priority entries are full, the iteration and
manipulation code is much simpler and behaves correctly re: the above bug;
and the fourth patch removes the unnecessary iteration.

The second patch adds some minor plist helper functions; nothing new
really, just functions to match existing regular list functions.  These
are used by the next two patches.

The third patch adds plist_requeue(), which is used by get_swap_page() in
the next patch - it performs the requeueing of same-priority entries
(which moves the entry to the end of its priority in the plist), so that
all equal-priority swap_info_structs get used equally.

The fourth patch converts the main list into a plist, and adds a new plist
that contains only swap_info entries that are both active and not full.
As Mel suggested using plists allows removing all the ordering code from
swap - plists handle ordering automatically.  The list naming is also
clarified now that there are two lists, with the original list changed
from swap_list_head to swap_active_head and the new list named
swap_avail_head.  A new spinlock is also added for the new list, so
swap_info entries can be added or removed from the new list immediately as
they become full or not full.

This patch (of 4):

Replace the singly-linked list tracking active, i.e.  swapon'ed,
swap_info_struct entries with a doubly-linked list using struct
list_heads.  Simplify the logic iterating and manipulating the list of
entries, especially get_swap_page(), by using standard list_head
functions, and removing the highest priority iteration logic.

The change fixes the bug:
https://lkml.org/lkml/2014/2/13/181
in which different priority swap entries after the highest priority entry
are incorrectly used equally in pairs.  The swap behavior is now as
advertised, i.e. different priority swap entries are used in order, and
equal priority swap targets are used concurrently.

Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Shaohua Li <shli@fusionio.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
Cc: Weijie Yang <weijieut@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Bob Liu <bob.liu@oracle.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-09 12:21:27 -07:00
Michal Hocko a4c51bde13 mm: exclude memoryless nodes from zone_reclaim
commit 70ef57e6c2 upstream.

We had a report about strange OOM killer strikes on a PPC machine
although there was a lot of swap free and a tons of anonymous memory
which could be swapped out.  In the end it turned out that the OOM was a
side effect of zone reclaim which wasn't unmapping and swapping out and
so the system was pushed to the OOM.  Although this sounds like a bug
somewhere in the kswapd vs.  zone reclaim vs.  direct reclaim
interaction numactl on the said hardware suggests that the zone reclaim
should not have been set in the first place:

  node 0 cpus: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
  node 0 size: 0 MB
  node 0 free: 0 MB
  node 2 cpus:
  node 2 size: 7168 MB
  node 2 free: 6019 MB
  node distances:
  node   0   2
  0:  10  40
  2:  40  10

So all the CPUs are associated with Node0 which doesn't have any memory
while Node2 contains all the available memory.  Node distances cause an
automatic zone_reclaim_mode enabling.

Zone reclaim is intended to keep the allocations local but this doesn't
make any sense on the memoryless nodes.  So let's exclude such nodes for
init_zone_allows_reclaim which evaluates zone reclaim behavior and
suitable reclaim_nodes.

Signed-off-by: Michal Hocko <mhocko@suse.cz>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Nishanth Aravamudan <nacc@linux.vnet.ibm.com>
Tested-by: Nishanth Aravamudan <nacc@linux.vnet.ibm.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-09 12:21:27 -07:00
Andrew Hunter 5c0f0c017c jiffies: Fix timeval conversion to jiffies
commit d78c9300c5 upstream.

timeval_to_jiffies tried to round a timeval up to an integral number
of jiffies, but the logic for doing so was incorrect: intervals
corresponding to exactly N jiffies would become N+1. This manifested
itself particularly repeatedly stopping/starting an itimer:

setitimer(ITIMER_PROF, &val, NULL);
setitimer(ITIMER_PROF, NULL, &val);

would add a full tick to val, _even if it was exactly representable in
terms of jiffies_ (say, the result of a previous rounding.)  Doing
this repeatedly would cause unbounded growth in val.  So fix the math.

Here's what was wrong with the conversion: we essentially computed
(eliding seconds)

jiffies = usec  * (NSEC_PER_USEC/TICK_NSEC)

by using scaling arithmetic, which took the best approximation of
NSEC_PER_USEC/TICK_NSEC with denominator of 2^USEC_JIFFIE_SC =
x/(2^USEC_JIFFIE_SC), and computed:

jiffies = (usec * x) >> USEC_JIFFIE_SC

and rounded this calculation up in the intermediate form (since we
can't necessarily exactly represent TICK_NSEC in usec.) But the
scaling arithmetic is a (very slight) *over*approximation of the true
value; that is, instead of dividing by (1 usec/ 1 jiffie), we
effectively divided by (1 usec/1 jiffie)-epsilon (rounding
down). This would normally be fine, but we want to round timeouts up,
and we did so by adding 2^USEC_JIFFIE_SC - 1 before the shift; this
would be fine if our division was exact, but dividing this by the
slightly smaller factor was equivalent to adding just _over_ 1 to the
final result (instead of just _under_ 1, as desired.)

In particular, with HZ=1000, we consistently computed that 10000 usec
was 11 jiffies; the same was true for any exact multiple of
TICK_NSEC.

We could possibly still round in the intermediate form, adding
something less than 2^USEC_JIFFIE_SC - 1, but easier still is to
convert usec->nsec, round in nanoseconds, and then convert using
time*spec*_to_jiffies.  This adds one constant multiplication, and is
not observably slower in microbenchmarks on recent x86 hardware.

Tested: the following program:

int main() {
  struct itimerval zero = {{0, 0}, {0, 0}};
  /* Initially set to 10 ms. */
  struct itimerval initial = zero;
  initial.it_interval.tv_usec = 10000;
  setitimer(ITIMER_PROF, &initial, NULL);
  /* Save and restore several times. */
  for (size_t i = 0; i < 10; ++i) {
    struct itimerval prev;
    setitimer(ITIMER_PROF, &zero, &prev);
    /* on old kernels, this goes up by TICK_USEC every iteration */
    printf("previous value: %ld %ld %ld %ld\n",
           prev.it_interval.tv_sec, prev.it_interval.tv_usec,
           prev.it_value.tv_sec, prev.it_value.tv_usec);
    setitimer(ITIMER_PROF, &prev, NULL);
  }
    return 0;
}


Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Paul Turner <pjt@google.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Reviewed-by: Paul Turner <pjt@google.com>
Reported-by: Aaron Jacobs <jacobsa@google.com>
Signed-off-by: Andrew Hunter <ahh@google.com>
[jstultz: Tweaked to apply to 3.17-rc]
Signed-off-by: John Stultz <john.stultz@linaro.org>
[bwh: Backported to 3.16: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-09 12:21:27 -07:00
Hans Verkuil cbb87efb98 media: vb2: fix VBI/poll regression
commit 58d75f4b1c upstream.

The recent conversion of saa7134 to vb2 unconvered a poll() bug that
broke the teletext applications alevt and mtt. These applications
expect that calling poll() without having called VIDIOC_STREAMON will
cause poll() to return POLLERR. That did not happen in vb2.

This patch fixes that behavior. It also fixes what should happen when
poll() is called when STREAMON is called but no buffers have been
queued. In that case poll() will also return POLLERR, but only for
capture queues since output queues will always return POLLOUT
anyway in that situation.

This brings the vb2 behavior in line with the old videobuf behavior.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-09 12:21:27 -07:00
Mel Gorman 5f50c44d8a mm: numa: Do not mark PTEs pte_numa when splitting huge pages
commit abc40bd2ee upstream.

This patch reverts 1ba6e0b50b ("mm: numa: split_huge_page: transfer the
NUMA type from the pmd to the pte"). If a huge page is being split due
a protection change and the tail will be in a PROT_NONE vma then NUMA
hinting PTEs are temporarily created in the protected VMA.

 VM_RW|VM_PROTNONE
|-----------------|
      ^
      split here

In the specific case above, it should get fixed up by change_pte_range()
but there is a window of opportunity for weirdness to happen. Similarly,
if a huge page is shrunk and split during a protection update but before
pmd_numa is cleared then a pte_numa can be left behind.

Instead of adding complexity trying to deal with the case, this patch
will not mark PTEs NUMA when splitting a huge page. NUMA hinting faults
will not be triggered which is marginal in comparison to the complexity
in dealing with the corner cases during THP split.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-09 12:21:27 -07:00
Waiman Long 1da286ebc5 mm, thp: move invariant bug check out of loop in __split_huge_page_map
commit f8303c2582 upstream.

In __split_huge_page_map(), the check for page_mapcount(page) is
invariant within the for loop.  Because of the fact that the macro is
implemented using atomic_read(), the redundant check cannot be optimized
away by the compiler leading to unnecessary read to the page structure.

This patch moves the invariant bug check out of the loop so that it will
be done only once.  On a 3.16-rc1 based kernel, the execution time of a
microbenchmark that broke up 1000 transparent huge pages using munmap()
had an execution time of 38,245us and 38,548us with and without the
patch respectively.  The performance gain is about 1%.

Signed-off-by: Waiman Long <Waiman.Long@hp.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Scott J Norton <scott.norton@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-09 12:21:27 -07:00
Nishanth Aravamudan de1fc405fb hugetlb: ensure hugepage access is denied if hugepages are not supported
commit 457c1b27ed upstream.

Currently, I am seeing the following when I `mount -t hugetlbfs /none
/dev/hugetlbfs`, and then simply do a `ls /dev/hugetlbfs`.  I think it's
related to the fact that hugetlbfs is properly not correctly setting
itself up in this state?:

  Unable to handle kernel paging request for data at address 0x00000031
  Faulting instruction address: 0xc000000000245710
  Oops: Kernel access of bad area, sig: 11 [#1]
  SMP NR_CPUS=2048 NUMA pSeries
  ....

In KVM guests on Power, in a guest not backed by hugepages, we see the
following:

  AnonHugePages:         0 kB
  HugePages_Total:       0
  HugePages_Free:        0
  HugePages_Rsvd:        0
  HugePages_Surp:        0
  Hugepagesize:         64 kB

HPAGE_SHIFT == 0 in this configuration, which indicates that hugepages
are not supported at boot-time, but this is only checked in
hugetlb_init().  Extract the check to a helper function, and use it in a
few relevant places.

This does make hugetlbfs not supported (not registered at all) in this
environment.  I believe this is fine, as there are no valid hugepages
and that won't change at runtime.

[akpm@linux-foundation.org: use pr_info(), per Mel]
[akpm@linux-foundation.org: fix build when HPAGE_SHIFT is undefined]
Signed-off-by: Nishanth Aravamudan <nacc@linux.vnet.ibm.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-09 12:21:27 -07:00
Pavel Shilovsky 04ceeee9bb CIFS: Fix SMB2 readdir error handling
commit 52755808d4 upstream.

SMB2 servers indicates the end of a directory search with
STATUS_NO_MORE_FILE error code that is not processed now.
This causes generic/257 xfstest to fail. Fix this by triggering
the end of search by this error code in SMB2_query_directory.

Also when negotiating CIFS protocol we tell the server to close
the search automatically at the end and there is no need to do
it itself. In the case of SMB2 protocol, we need to close it
explicitly - separate close directory checks for different
protocols.

Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-09 12:21:27 -07:00
Steven Rostedt (Red Hat) 3a525e2316 ring-buffer: Fix infinite spin in reading buffer
commit 24607f114f upstream.

Commit 651e22f270 "ring-buffer: Always reset iterator to reader page"
fixed one bug but in the process caused another one. The reset is to
update the header page, but that fix also changed the way the cached
reads were updated. The cache reads are used to test if an iterator
needs to be updated or not.

A ring buffer iterator, when created, disables writes to the ring buffer
but does not stop other readers or consuming reads from happening.
Although all readers are synchronized via a lock, they are only
synchronized when in the ring buffer functions. Those functions may
be called by any number of readers. The iterator continues down when
its not interrupted by a consuming reader. If a consuming read
occurs, the iterator starts from the beginning of the buffer.

The way the iterator sees that a consuming read has happened since
its last read is by checking the reader "cache". The cache holds the
last counts of the read and the reader page itself.

Commit 651e22f270 changed what was saved by the cache_read when
the rb_iter_reset() occurred, making the iterator never match the cache.
Then if the iterator calls rb_iter_reset(), it will go into an
infinite loop by checking if the cache doesn't match, doing the reset
and retrying, just to see that the cache still doesn't match! Which
should never happen as the reset is suppose to set the cache to the
current value and there's locks that keep a consuming reader from
having access to the data.

Fixes: 651e22f270 "ring-buffer: Always reset iterator to reader page"
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-09 12:21:27 -07:00
Josh Triplett 769721dbd6 init/Kconfig: Fix HAVE_FUTEX_CMPXCHG to not break up the EXPERT menu
commit 62b4d20411 upstream.

commit 03b8c7b623 ("futex: Allow
architectures to skip futex_atomic_cmpxchg_inatomic() test") added the
HAVE_FUTEX_CMPXCHG symbol right below FUTEX.  This placed it right in
the middle of the options for the EXPERT menu.  However,
HAVE_FUTEX_CMPXCHG does not depend on EXPERT or FUTEX, so Kconfig stops
placing items in the EXPERT menu, and displays the remaining several
EXPERT items (starting with EPOLL) directly in the General Setup menu.

Since both users of HAVE_FUTEX_CMPXCHG only select it "if FUTEX", make
HAVE_FUTEX_CMPXCHG itself depend on FUTEX.  With this change, the
subsequent items display as part of the EXPERT menu again; the EMBEDDED
menu now appears as the next top-level item in the General Setup menu,
which makes General Setup much shorter and more usable.

Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-09 12:21:26 -07:00
Steve French f012edf688 Fix problem recognizing symlinks
commit 19e81573fc upstream.

Changeset eb85d94bd introduced a problem where if a cifs open
fails during query info of a file we
will still try to close the file (happens with certain types
of reparse points) even though the file handle is not valid.

In addition for SMB2/SMB3 we were not mapping the return code returned
by Windows when trying to open a file (like a Windows NFS symlink)
which is a reparse point.

Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-09 12:21:26 -07:00
Chris Wilson 7365af4980 drm/i915: Flush the PTEs after updating them before suspend
commit 91e5649930 upstream.

As we use WC updates of the PTE, we are responsible for notifying the
hardware when to flush its TLBs. Do so after we zap all the PTEs before
suspend (and the BIOS tries to read our GTT).

Fixes a regression from

commit 828c79087c
Author: Ben Widawsky <benjamin.widawsky@intel.com>
Date:   Wed Oct 16 09:21:30 2013 -0700

    drm/i915: Disable GGTT PTEs on GEN6+ suspend

that survived and continue to cause harm even after

commit e568af1c62
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Wed Mar 26 20:08:20 2014 +0100

    drm/i915: Undo gtt scratch pte unmapping again

v2: Trivial rebase.
v3: Fixes requires pointer dances.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=82340
Tested-by: ming.yao@intel.com
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Todd Previte <tprevite@gmail.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-09 12:21:26 -07:00
NeilBrown 6af970fada md/raid5: disable 'DISCARD' by default due to safety concerns.
commit 8e0e99ba64 upstream.

It has come to my attention (thanks Martin) that 'discard_zeroes_data'
is only a hint.  Some devices in some cases don't do what it
says on the label.

The use of DISCARD in RAID5 depends on reads from discarded regions
being predictably zero.  If a write to a previously discarded region
performs a read-modify-write cycle it assumes that the parity block
was consistent with the data blocks.  If all were zero, this would
be the case.  If some are and some aren't this would not be the case.
This could lead to data corruption after a device failure when
data needs to be reconstructed from the parity.

As we cannot trust 'discard_zeroes_data', ignore it by default
and so disallow DISCARD on all raid4/5/6 arrays.

As many devices are trustworthy, and as there are benefits to using
DISCARD, add a module parameter to over-ride this caution and cause
DISCARD to work if discard_zeroes_data is set.

If a site want to enable DISCARD on some arrays but not on others they
should select DISCARD support at the filesystem level, and set the
raid456 module parameter.
    raid456.devices_handle_discard_safely=Y

As this is a data-safety issue, I believe this patch is suitable for
-stable.
DISCARD support for RAID456 was added in 3.7

Cc: Shaohua Li <shli@kernel.org>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Heinz Mauelshagen <heinzm@redhat.com>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Fixes: 620125f2bf
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-09 12:21:26 -07:00
Arnd Bergmann da893cbeda cpufreq: integrator: fix integrator_cpufreq_remove return type
commit d62dbf77f7 upstream.

When building this driver as a module, we get a helpful warning
about the return type:

drivers/cpufreq/integrator-cpufreq.c:232:2: warning: initialization from incompatible pointer type
  .remove = __exit_p(integrator_cpufreq_remove),

If the remove callback returns void, the caller gets an undefined
value as it expects an integer to be returned. This fixes the
problem by passing down the value from cpufreq_unregister_driver.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-09 12:21:26 -07:00
Mel Gorman 5b81f9368a mm: migrate: Close race between migration completion and mprotect
commit d3cb8bf608 upstream.

A migration entry is marked as write if pte_write was true at the time the
entry was created. The VMA protections are not double checked when migration
entries are being removed as mprotect marks write-migration-entries as
read. It means that potentially we take a spurious fault to mark PTEs write
again but it's straight-forward. However, there is a race between write
migrations being marked read and migrations finishing. This potentially
allows a PTE to be write that should have been read. Close this race by
double checking the VMA permissions using maybe_mkwrite when migration
completes.

[torvalds@linux-foundation.org: use maybe_mkwrite]
Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-09 12:21:26 -07:00
Peter Zijlstra fddac5ed76 perf: fix perf bug in fork()
commit 6c72e3501d upstream.

Oleg noticed that a cleanup by Sylvain actually uncovered a bug; by
calling perf_event_free_task() when failing sched_fork() we will not yet
have done the memset() on ->perf_event_ctxp[] and will therefore try and
'free' the inherited contexts, which are still in use by the parent
process.  This is bad..

Suggested-by: Oleg Nesterov <oleg@redhat.com>
Reported-by: Oleg Nesterov <oleg@redhat.com>
Reported-by: Sylvain 'ythier' Hitier <sylvain.hitier@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-09 12:21:26 -07:00
Jan Kara 8233522673 udf: Avoid infinite loop when processing indirect ICBs
commit c03aa9f6e1 upstream.

We did not implement any bound on number of indirect ICBs we follow when
loading inode. Thus corrupted medium could cause kernel to go into an
infinite loop, possibly causing a stack overflow.

Fix the possible stack overflow by removing recursion from
__udf_read_inode() and limit number of indirect ICBs we follow to avoid
infinite loops.

Signed-off-by: Jan Kara <jack@suse.cz>
Cc: Chuck Ebbert <cebbert.lkml@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-09 12:21:26 -07:00
Greg Kroah-Hartman 2023c00d65 Linux 3.14.20 2014-10-05 14:52:37 -07:00
Rajendra Nayak bf3dbab538 ARM: DRA7: Add support for soc_is_dra74x() and soc_is_dra72x() variants
commit af438fec6c upstream.

Use the corresponding compatibles to identify the devices.

Signed-off-by: Rajendra Nayak <rnayak@ti.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Acked-by: Nishanth Menon <nm@ti.com>
Tested-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-05 14:52:24 -07:00
Stephen Boyd 62336a52a9 clk: qcom: mdp_lut_clk is a child of mdp_src
commit f87dfcabc6 upstream.

The mdp_lut_clk isn't a child of the mdp_clk. Instead it's the
child of the mdp_src clock. Fix it.

Fixes: 6d00b56fe "clk: qcom: Add support for MSM8960's multimedia clock controller (MMCC)"
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-05 14:52:24 -07:00
Stephen Boyd 4a6c0a1ad6 clk: qcom: Fix MN frequency tables, parent map, and jpegd
commit ff20783f7b upstream.

Clocks that don't have a pre-divider don't list any pre-divider
in their frequency tables, but their tables are initialized using
aggregate initializers. Use tagged initializers so we properly
assign the m and n values for each frequency. Furthermore, the
mmcc_pxo_pll8_pll2_pll3 array improperly mapped the second
element to pll2 instead of pll8, causing the clock driver to
recalculate the wrong rate for any clocks using this array along
with a rate that uses pll2. Plus the .num_parents field is 3
instead of 4 so you can't even switch the parent to pll3. Finally
I noticed that the jpegd clock improperly indicates that the
pre-divider width is only 2, when it's actually 4 bits wide.

Fixes: 6d00b56fe "clk: qcom: Add support for MSM8960's multimedia clock controller (MMCC)"
Tested-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-05 14:52:24 -07:00
Arnd Bergmann 5cbde12cc9 staging/lustre: disable virtual block device for 64K pages
commit 0bf22be0da upstream.

The lustre virtual block device cannot handle 64K pages and fails at compile
time. To avoid running into this error, let's disable the Kconfig option
for this driver in cases it doesn't support.

Reported-by: Dann Frazier <dann.frazier@canonical.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-05 14:52:24 -07:00
Gu Zheng 0be0ec9c36 aio: block exit_aio() until all context requests are completed
commit 6098b45b32 upstream.

It seems that exit_aio() also needs to wait for all iocbs to complete (like
io_destroy), but we missed the wait step in current implemention, so fix
it in the same way as we did in io_destroy.

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2014-10-05 14:52:24 -07:00
Tero Kristo ed7150a026 clk: prevent erronous parsing of children during rate change
commit 067bb1741c upstream.

In some cases, clocks can switch their parent with clk_set_rate, for
example clk_mux can do this in some cases. Current implementation of
clk_change_rate uses un-safe list iteration on the clock children, which
will cause wrong clocks to be parsed in case any of the clock children
change their parents during the change rate operation. Fixed by using
the safe list iterator instead.

The problem was detected due to some divide by zero errors generated
by clock init on dra7-evm board, see discussion under
http://article.gmane.org/gmane.linux.ports.arm.kernel/349180 for details.

Fixes: 71472c0c06 ("clk: add support for clock reparent on set_rate")
Signed-off-by: Tero Kristo <t-kristo@ti.com>
Reported-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-05 14:52:24 -07:00
Venkatesh Srinivas 2968314094 perf/x86/intel: Use rdmsrl_safe() when initializing RAPL PMU
commit 2422365780 upstream.

CPUs which should support the RAPL counters according to
Family/Model/Stepping may still issue #GP when attempting to access
the RAPL MSRs. This may happen when Linux is running under KVM and
we are passing-through host F/M/S data, for example. Use rdmsrl_safe
to first access the RAPL_POWER_UNIT MSR; if this fails, do not
attempt to use this PMU.

Signed-off-by: Venkatesh Srinivas <venkateshs@google.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1394739386-22260-1-git-send-email-venkateshs@google.com
Cc: zheng.z.yan@intel.com
Cc: eranian@google.com
Cc: ak@linux.intel.com
Cc: linux-kernel@vger.kernel.org
[ The patch also silently fixes another bug: rapl_pmu_init() didn't handle the memory alloc failure case previously. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
[backport by whissi]
Cc: Thomas D <whissi@whissi.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-05 14:52:24 -07:00
Dan Carpenter 763e95c4ac partitions: aix.c: off by one bug
commit d97a86c170 upstream.

The lvip[] array has "state->limit" elements so the condition here
should be >= instead of >.

Fixes: 6ceea22bbb ('partitions: add aix lvm partition support files')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Philippe De Muyter <phdm@macqel.be>
Signed-off-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-05 14:52:24 -07:00
Andy Shevchenko 5257a3de5b dmaengine: dw: don't perform DMA when dmaengine_submit is called
commit dd8ecfcac6 upstream.

Accordingly to discussion [1] and followed up documentation the DMA controller
driver shouldn't start any DMA operations when dmaengine_submit() is called.

This patch fixes the workflow in dw_dmac driver to follow the documentation.

[1] http://www.spinics.net/lists/arm-kernel/msg125987.html

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Cc: "Petallo, MauriceX R" <mauricex.r.petallo@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-05 14:52:24 -07:00
Andy Shevchenko 97a4115f3d dmaengine: dw: introduce dwc_dostart_first_queued() helper
commit e7637c6c03 upstream.

We have a duplicate code which starts first descriptor in the queue. Let's make
this as a separate helper that can be used in future as well.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Cc: "Petallo, MauriceX R" <mauricex.r.petallo@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-05 14:52:24 -07:00