Roman Gushchin 9b6f7e163c mm: rework memcg kernel stack accounting ... If CONFIG_VMAP_STACK is set, kernel stacks are allocated using __vmalloc_node_range() with __GFP_ACCOUNT. So kernel stack pages are charged against corresponding memory cgroups on allocation and uncharged on releasing them. The problem is that we do cache kernel stacks in small per-cpu caches and do reuse them for new tasks, which can belong to different memory cgroups. Each stack page still holds a reference to the original cgroup, so the cgroup can't be released until the vmap area is released. To make this happen we need more than two subsequent exits without forks in between on the current cpu, which makes it very unlikely to happen. As a result, I saw a significant number of dying cgroups (in theory, up to 2 * number_of_cpu + number_of_tasks), which can't be released even by significant memory pressure. As a cgroup structure can take a significant amount of memory (first of all, per-cpu data like memcg statistics), it leads to a noticeable waste of memory. Link: http://lkml.kernel.org/r/20180827162621.30187-1-guro@fb.com Fixes: ac496bf48d ("fork: Optimize task creation by caching two thread stacks per CPU if CONFIG_VMAP_STACK=y") Signed-off-by: Roman Gushchin <guro@fb.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Acked-by: Michal Hocko <mhocko@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2018-10-26 16:25:19 -07:00
..
bpf	Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next	2018-10-21 21:11:46 -07:00
cgroup	for-4.20/block-20181021	2018-10-22 17:46:08 +01:00
configs	…
debug	…
dma	dma-direct: respect DMA_ATTR_NO_WARN	2018-10-09 15:08:46 +02:00
events	Merge branch 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace	2018-10-24 11:22:39 +01:00
gcov	…
irq	Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2018-10-25 11:43:47 -07:00
livepatch	Merge branch 'for-4.19/upstream' into for-linus	2018-08-20 18:33:50 +02:00
locking	Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2018-10-23 13:08:53 +01:00
power	Merge branches 'acpi-pm' and 'pm-sleep'	2018-10-18 12:27:30 +02:00
printk	printk: fix integer overflow in setup_log_buf()	2018-10-12 10:44:17 +02:00
rcu	Merge branches 'doc.2018.08.30a', 'dynticks.2018.08.30b', 'srcu.2018.08.30b' and 'torture.2018.08.29a' into HEAD	2018-08-30 16:12:53 -07:00
sched	Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2018-10-25 11:14:36 -07:00
time	Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2018-10-25 11:14:36 -07:00
trace	for-4.20/block-20181021	2018-10-22 17:46:08 +01:00
.gitignore	…
Kconfig.freezer	…
Kconfig.hz	…
Kconfig.locks	…
Kconfig.preempt	kconfig: include kernel/Kconfig.preempt from init/Kconfig	2018-08-02 08:06:54 +09:00
Makefile	kbuild: move bin2c back to scripts/ from scripts/basic/	2018-07-18 01:18:05 +09:00
acct.c	…
async.c	…
audit.c	audit: use ktime_get_coarse_real_ts64() for timestamps	2018-07-17 14:45:08 -04:00
audit.h	…
audit_fsnotify.c	…
audit_tree.c	\n	2018-08-17 09:41:28 -07:00
audit_watch.c	audit: fix use-after-free in audit_add_watch	2018-07-18 11:43:36 -04:00
auditfilter.c	…
auditsc.c	audit/stable-4.18 PR 20180814	2018-08-15 10:46:54 -07:00
backtracetest.c	…
bounds.c	…
capability.c	…
compat.c	y2038: globally rename compat_time to old_time32	2018-08-27 14:48:48 +02:00
configs.c	…
context_tracking.c	…
cpu.c	Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2018-10-23 18:43:04 +01:00
cpu_pm.c	…
crash_core.c	kernel/crash_core.c: print timestamp using time64_t	2018-08-22 10:52:47 -07:00
crash_dump.c	…
cred.c	…
delayacct.c	…
dma.c	…
elfcore.c	…
exec_domain.c	…
exit.c	signal: Pass pid type into group_send_sig_info	2018-07-21 12:57:35 -05:00
extable.c	…
fail_function.c	…
fork.c	mm: rework memcg kernel stack accounting	2018-10-26 16:25:19 -07:00
freezer.c	PM / reboot: Eliminate race between reboot and suspend	2018-08-06 12:35:20 +02:00
futex.c	futex: Replace spin_is_locked() with lockdep	2018-10-09 13:19:28 +02:00
futex_compat.c	y2038: globally rename compat_time to old_time32	2018-08-27 14:48:48 +02:00
groups.c	…
hung_task.c	kernel/hung_task.c: allow to set checking interval separately from timeout	2018-08-22 10:52:47 -07:00
iomem.c	…
irq_work.c	…
jump_label.c	Merge branch 'x86/build' into locking/core, to pick up dependent patches and unify jump-label work	2018-10-16 17:30:11 +02:00
kallsyms.c	kallsyms, x86: Export addresses of PTI entry trampolines	2018-08-14 19:12:29 -03:00
kcmp.c	…
kcov.c	…
kexec.c	kexec: add call to LSM hook in original kexec_load syscall	2018-07-16 12:31:57 -07:00
kexec_core.c	kexec: Allocate decrypted control pages for kdump if SME is enabled	2018-10-06 12:01:51 +02:00
kexec_file.c	…
kexec_internal.h	…
kmod.c	…
kprobes.c	kprobes: Don't call BUG_ON() if there is a kprobe in use on free list	2018-09-12 08:01:16 +02:00
ksysfs.c	…
kthread.c	Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2018-08-13 11:25:07 -07:00
latencytop.c	…
memremap.c	libnvdimm-for-4.19_dax-memory-failure	2018-08-25 18:43:59 -07:00
module-internal.h	…
module.c	jump_table: Move entries into ro_after_init region	2018-09-27 17:56:49 +02:00
module_signing.c	…
notifier.c	…
nsproxy.c	…
padata.c	…
panic.c	…
params.c	…
pid.c	fork: report pid exhaustion correctly	2018-09-20 22:01:11 +02:00
pid_namespace.c	signal: Use group_send_sig_info to kill all processes in a pid namespace	2018-09-16 16:08:25 +02:00
profile.c	…
ptrace.c	Merge branch 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace	2018-10-24 11:22:39 +01:00
range.c	…
reboot.c	kernel/reboot.c: export pm_power_off_prepare	2018-09-11 16:13:24 +01:00
relay.c	…
resource.c	resource: Clean it up a bit	2018-10-09 17:25:58 +02:00
rseq.c	…
seccomp.c	Merge branch 'next-general' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security	2018-10-24 11:49:35 +01:00
signal.c	Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2018-10-25 11:14:36 -07:00
smp.c	smp,cpumask: introduce on_each_cpu_cond_mask	2018-10-09 16:51:11 +02:00
smpboot.c	…
smpboot.h	…
softirq.c	Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2018-10-25 11:43:47 -07:00
stacktrace.c	…
stop_machine.c	Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2018-08-13 11:25:07 -07:00
sys.c	kernel/sys.c: remove duplicated include	2018-09-20 22:01:11 +02:00
sys_ni.c	…
sysctl.c	namei: allow restricted O_CREAT of FIFOs and regular files	2018-08-23 18:48:43 -07:00
sysctl_binary.c	…
task_work.c	…
taskstats.c	…
test_kprobes.c	…
torture.c	rcutorture: Check GP completion at stutter end	2018-08-29 09:20:48 -07:00
tracepoint.c	tracepoint: Fix tracepoint array element size mismatch	2018-10-17 15:35:29 -04:00
tsacct.c	…
ucount.c	…
uid16.c	…
uid16.h	…
umh.c	umh: Add command line to user mode helpers	2018-10-22 19:37:36 -07:00
up.c	smp,cpumask: introduce on_each_cpu_cond_mask	2018-10-09 16:51:11 +02:00
user-return-notifier.c	…
user.c	userns: use irqsave variant of refcount_dec_and_lock()	2018-08-22 10:52:47 -07:00
user_namespace.c	userns: move user access out of the mutex	2018-08-11 02:05:53 -05:00
utsname.c	…
utsname_sysctl.c	sys: don't hold uts_sem while accessing userspace memory	2018-08-11 02:05:53 -05:00
watchdog.c	watchdog: Mark watchdog touch functions as notrace	2018-08-30 12:56:40 +02:00
watchdog_hld.c	watchdog: Mark watchdog touch functions as notrace	2018-08-30 12:56:40 +02:00
workqueue.c	watchdog: Mark watchdog touch functions as notrace	2018-08-30 12:56:40 +02:00
workqueue_internal.h	…