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commit 7d36665a5886c27ca4c4d0afd3ecc50b400f3587 upstream.
An eventfd monitors multiple memory thresholds of the cgroup, closes them,
the kernel deletes all events related to this eventfd. Before all events
are deleted, another eventfd monitors the memory threshold of this cgroup,
leading to a crash:
BUG: kernel NULL pointer dereference, address: 0000000000000004
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 800000033058e067 P4D 800000033058e067 PUD 3355ce067 PMD 0
Oops: 0002 [#1] SMP PTI
CPU: 2 PID: 14012 Comm: kworker/2:6 Kdump: loaded Not tainted 5.6.0-rc4 #3
Hardware name: LENOVO 20AWS01K00/20AWS01K00, BIOS GLET70WW (2.24 ) 05/21/2014
Workqueue: events memcg_event_remove
RIP: 0010:__mem_cgroup_usage_unregister_event+0xb3/0x190
RSP: 0018:ffffb47e01c4fe18 EFLAGS: 00010202
RAX: 0000000000000001 RBX: ffff8bb223a8a000 RCX: 0000000000000001
RDX: 0000000000000001 RSI: ffff8bb22fb83540 RDI: 0000000000000001
RBP: ffffb47e01c4fe48 R08: 0000000000000000 R09: 0000000000000010
R10: 000000000000000c R11: 071c71c71c71c71c R12: ffff8bb226aba880
R13: ffff8bb223a8a480 R14: 0000000000000000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8bb242680000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000004 CR3: 000000032c29c003 CR4: 00000000001606e0
Call Trace:
memcg_event_remove+0x32/0x90
process_one_work+0x172/0x380
worker_thread+0x49/0x3f0
kthread+0xf8/0x130
ret_from_fork+0x35/0x40
CR2: 0000000000000004
We can reproduce this problem in the following ways:
1. We create a new cgroup subdirectory and a new eventfd, and then we
monitor multiple memory thresholds of the cgroup through this eventfd.
2. closing this eventfd, and __mem_cgroup_usage_unregister_event ()
will be called multiple times to delete all events related to this
eventfd.
The first time __mem_cgroup_usage_unregister_event() is called, the
kernel will clear all items related to this eventfd in thresholds->
primary.
Since there is currently only one eventfd, thresholds-> primary becomes
empty, so the kernel will set thresholds-> primary and hresholds-> spare
to NULL. If at this time, the user creates a new eventfd and monitor
the memory threshold of this cgroup, kernel will re-initialize
thresholds-> primary.
Then when __mem_cgroup_usage_unregister_event () is called for the
second time, because thresholds-> primary is not empty, the system will
access thresholds-> spare, but thresholds-> spare is NULL, which will
trigger a crash.
In general, the longer it takes to delete all events related to this
eventfd, the easier it is to trigger this problem.
The solution is to check whether the thresholds associated with the
eventfd has been cleared when deleting the event. If so, we do nothing.
[akpm@linux-foundation.org: fix comment, per Kirill]
Fixes: 907860ed381a ("cgroups: make cftype.unregister_event() void-returning")
Signed-off-by: Chunguang Xu <brookxu@tencent.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/077a6f67-aefa-4591-efec-f2f3af2b0b02@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit e876ecc67db80dfdb8e237f71e5b43bb88ae549c ]
We are testing network memory accounting in our setup and noticed
inconsistent network memory usage and often unrelated cgroups network
usage correlates with testing workload. On further inspection, it
seems like mem_cgroup_sk_alloc() and cgroup_sk_alloc() are broken in
irq context specially for cgroup v1.
mem_cgroup_sk_alloc() and cgroup_sk_alloc() can be called in irq context
and kind of assumes that this can only happen from sk_clone_lock()
and the source sock object has already associated cgroup. However in
cgroup v1, where network memory accounting is opt-in, the source sock
can be unassociated with any cgroup and the new cloned sock can get
associated with unrelated interrupted cgroup.
Cgroup v2 can also suffer if the source sock object was created by
process in the root cgroup or if sk_alloc() is called in irq context.
The fix is to just do nothing in interrupt.
WARNING: Please note that about half of the TCP sockets are allocated
from the IRQ context, so, memory used by such sockets will not be
accouted by the memcg.
The stack trace of mem_cgroup_sk_alloc() from IRQ-context:
CPU: 70 PID: 12720 Comm: ssh Tainted: 5.6.0-smp-DEV #1
Hardware name: ...
Call Trace:
<IRQ>
dump_stack+0x57/0x75
mem_cgroup_sk_alloc+0xe9/0xf0
sk_clone_lock+0x2a7/0x420
inet_csk_clone_lock+0x1b/0x110
tcp_create_openreq_child+0x23/0x3b0
tcp_v6_syn_recv_sock+0x88/0x730
tcp_check_req+0x429/0x560
tcp_v6_rcv+0x72d/0xa40
ip6_protocol_deliver_rcu+0xc9/0x400
ip6_input+0x44/0xd0
? ip6_protocol_deliver_rcu+0x400/0x400
ip6_rcv_finish+0x71/0x80
ipv6_rcv+0x5b/0xe0
? ip6_sublist_rcv+0x2e0/0x2e0
process_backlog+0x108/0x1e0
net_rx_action+0x26b/0x460
__do_softirq+0x104/0x2a6
do_softirq_own_stack+0x2a/0x40
</IRQ>
do_softirq.part.19+0x40/0x50
__local_bh_enable_ip+0x51/0x60
ip6_finish_output2+0x23d/0x520
? ip6table_mangle_hook+0x55/0x160
__ip6_finish_output+0xa1/0x100
ip6_finish_output+0x30/0xd0
ip6_output+0x73/0x120
? __ip6_finish_output+0x100/0x100
ip6_xmit+0x2e3/0x600
? ipv6_anycast_cleanup+0x50/0x50
? inet6_csk_route_socket+0x136/0x1e0
? skb_free_head+0x1e/0x30
inet6_csk_xmit+0x95/0xf0
__tcp_transmit_skb+0x5b4/0xb20
__tcp_send_ack.part.60+0xa3/0x110
tcp_send_ack+0x1d/0x20
tcp_rcv_state_process+0xe64/0xe80
? tcp_v6_connect+0x5d1/0x5f0
tcp_v6_do_rcv+0x1b1/0x3f0
? tcp_v6_do_rcv+0x1b1/0x3f0
__release_sock+0x7f/0xd0
release_sock+0x30/0xa0
__inet_stream_connect+0x1c3/0x3b0
? prepare_to_wait+0xb0/0xb0
inet_stream_connect+0x3b/0x60
__sys_connect+0x101/0x120
? __sys_getsockopt+0x11b/0x140
__x64_sys_connect+0x1a/0x20
do_syscall_64+0x51/0x200
entry_SYSCALL_64_after_hwframe+0x44/0xa9
The stack trace of mem_cgroup_sk_alloc() from IRQ-context:
Fixes: 2d7580738345 ("mm: memcontrol: consolidate cgroup socket tracking")
Fixes: d979a39d7242 ("cgroup: duplicate cgroup reference when cloning sockets")
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Roman Gushchin <guro@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 00d484f354d85845991b40141d40ba9e5eb60faf upstream.
We've encountered a rcu stall in get_mem_cgroup_from_mm():
rcu: INFO: rcu_sched self-detected stall on CPU
rcu: 33-....: (21000 ticks this GP) idle=6c6/1/0x4000000000000002 softirq=35441/35441 fqs=5017
(t=21031 jiffies g=324821 q=95837) NMI backtrace for cpu 33
<...>
RIP: 0010:get_mem_cgroup_from_mm+0x2f/0x90
<...>
__memcg_kmem_charge+0x55/0x140
__alloc_pages_nodemask+0x267/0x320
pipe_write+0x1ad/0x400
new_sync_write+0x127/0x1c0
__kernel_write+0x4f/0xf0
dump_emit+0x91/0xc0
writenote+0xa0/0xc0
elf_core_dump+0x11af/0x1430
do_coredump+0xc65/0xee0
get_signal+0x132/0x7c0
do_signal+0x36/0x640
exit_to_usermode_loop+0x61/0xd0
do_syscall_64+0xd4/0x100
entry_SYSCALL_64_after_hwframe+0x44/0xa9
The problem is caused by an exiting task which is associated with an
offline memcg. We're iterating over and over in the do {} while
(!css_tryget_online()) loop, but obviously the memcg won't become online
and the exiting task won't be migrated to a live memcg.
Let's fix it by switching from css_tryget_online() to css_tryget().
As css_tryget_online() cannot guarantee that the memcg won't go offline,
the check is usually useless, except some rare cases when for example it
determines if something should be presented to a user.
A similar problem is described by commit 18fa84a2db0e ("cgroup: Use
css_tryget() instead of css_tryget_online() in task_get_css()").
Johannes:
: The bug aside, it doesn't matter whether the cgroup is online for the
: callers. It used to matter when offlining needed to evacuate all charges
: from the memcg, and so needed to prevent new ones from showing up, but we
: don't care now.
Link: http://lkml.kernel.org/r/20191106225131.3543616-1-guro@fb.com
Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Shakeel Butt <shakeeb@google.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Koutn <mkoutny@suse.com>
Cc: <stable@vger.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>
[ Upstream commit 7e97de0b033bcac4fa9a35cef72e0c06e6a22c67 ]
In case of memcg_online_kmem() failure, memcg_cgroup::id remains hashed
in mem_cgroup_idr even after memcg memory is freed. This leads to leak
of ID in mem_cgroup_idr.
This patch adds removal into mem_cgroup_css_alloc(), which fixes the
problem. For better readability, it adds a generic helper which is used
in mem_cgroup_alloc() and mem_cgroup_id_put_many() as well.
Link: http://lkml.kernel.org/r/152354470916.22460.14397070748001974638.stgit@localhost.localdomain
Fixes 73f576c04b94 ("mm: memcontrol: fix cgroup creation failure after many small jobs")
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: 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>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 9f15bde671355c351cf20d9f879004b234353100 upstream.
It was reported that a kernel crash happened in mem_cgroup_iter(), which
can be triggered if the legacy cgroup-v1 non-hierarchical mode is used.
Unable to handle kernel paging request at virtual address 6b6b6b6b6b6b8f
......
Call trace:
mem_cgroup_iter+0x2e0/0x6d4
shrink_zone+0x8c/0x324
balance_pgdat+0x450/0x640
kswapd+0x130/0x4b8
kthread+0xe8/0xfc
ret_from_fork+0x10/0x20
mem_cgroup_iter():
......
if (css_tryget(css)) <-- crash here
break;
......
The crashing reason is that mem_cgroup_iter() uses the memcg object whose
pointer is stored in iter->position, which has been freed before and
filled with POISON_FREE(0x6b).
And the root cause of the use-after-free issue is that
invalidate_reclaim_iterators() fails to reset the value of iter->position
to NULL when the css of the memcg is released in non- hierarchical mode.
Link: http://lkml.kernel.org/r/1531994807-25639-1-git-send-email-jing.xia@unisoc.com
Fixes: 6df38689e0e9 ("mm: memcontrol: fix possible memcg leak due to interrupted reclaim")
Signed-off-by: Jing Xia <jing.xia.mail@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: <chunyan.zhang@unisoc.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: <stable@vger.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>
commit 18365225f0440d09708ad9daade2ec11275c3df9 upstream.
Laurent Dufour has noticed that hwpoinsoned pages are kept charged. In
his particular case he has hit a bad_page("page still charged to
cgroup") when onlining a hwpoison page. While this looks like something
that shouldn't happen in the first place because onlining hwpages and
returning them to the page allocator makes only little sense it shows a
real problem.
hwpoison pages do not get freed usually so we do not uncharge them (at
least not since commit 0a31bc97c80c ("mm: memcontrol: rewrite uncharge
API")). Each charge pins memcg (since e8ea14cc6ead ("mm: memcontrol:
take a css reference for each charged page")) as well and so the
mem_cgroup and the associated state will never go away. Fix this leak
by forcibly uncharging a LRU hwpoisoned page in delete_from_lru_cache().
We also have to tweak uncharge_list because it cannot rely on zero ref
count for these pages.
[akpm@linux-foundation.org: coding-style fixes]
Fixes: 0a31bc97c80c ("mm: memcontrol: rewrite uncharge API")
Link: http://lkml.kernel.org/r/20170502185507.GB19165@dhcp22.suse.cz
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Tested-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Reviewed-by: Balbir Singh <bsingharora@gmail.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.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>
[ Upstream commit bfc7228b9a9647e1c353e50b40297a2929801759 ]
The system may panic when initialisation is done when almost all the
memory is assigned to the huge pages using the kernel command line
parameter hugepage=xxxx. Panic may occur like this:
Unable to handle kernel paging request for data at address 0x00000000
Faulting instruction address: 0xc000000000302b88
Oops: Kernel access of bad area, sig: 11 [#1]
SMP NR_CPUS=2048 [ 0.082424] NUMA
pSeries
Modules linked in:
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.9.0-15-generic #16-Ubuntu
task: c00000021ed01600 task.stack: c00000010d108000
NIP: c000000000302b88 LR: c000000000270e04 CTR: c00000000016cfd0
REGS: c00000010d10b2c0 TRAP: 0300 Not tainted (4.9.0-15-generic)
MSR: 8000000002009033 <SF,VEC,EE,ME,IR,DR,RI,LE>[ 0.082770] CR: 28424422 XER: 00000000
CFAR: c0000000003d28b8 DAR: 0000000000000000 DSISR: 40000000 SOFTE: 1
GPR00: c000000000270e04 c00000010d10b540 c00000000141a300 c00000010fff6300
GPR04: 0000000000000000 00000000026012c0 c00000010d10b630 0000000487ab0000
GPR08: 000000010ee90000 c000000001454fd8 0000000000000000 0000000000000000
GPR12: 0000000000004400 c00000000fb80000 00000000026012c0 00000000026012c0
GPR16: 00000000026012c0 0000000000000000 0000000000000000 0000000000000002
GPR20: 000000000000000c 0000000000000000 0000000000000000 00000000024200c0
GPR24: c0000000016eef48 0000000000000000 c00000010fff7d00 00000000026012c0
GPR28: 0000000000000000 c00000010fff7d00 c00000010fff6300 c00000010d10b6d0
NIP mem_cgroup_soft_limit_reclaim+0xf8/0x4f0
LR do_try_to_free_pages+0x1b4/0x450
Call Trace:
do_try_to_free_pages+0x1b4/0x450
try_to_free_pages+0xf8/0x270
__alloc_pages_nodemask+0x7a8/0xff0
new_slab+0x104/0x8e0
___slab_alloc+0x620/0x700
__slab_alloc+0x34/0x60
kmem_cache_alloc_node_trace+0xdc/0x310
mem_cgroup_init+0x158/0x1c8
do_one_initcall+0x68/0x1d0
kernel_init_freeable+0x278/0x360
kernel_init+0x24/0x170
ret_from_kernel_thread+0x5c/0x74
Instruction dump:
eb81ffe0 eba1ffe8 ebc1fff0 ebe1fff8 4e800020 3d230001 e9499a42 3d220004
3929acd8 794a1f24 7d295214 eac90100 <e9360000> 2fa90000 419eff74 3b200000
---[ end trace 342f5208b00d01b6 ]---
This is a chicken and egg issue where the kernel try to get free memory
when allocating per node data in mem_cgroup_init(), but in that path
mem_cgroup_soft_limit_reclaim() is called which assumes that these data
are allocated.
As mem_cgroup_soft_limit_reclaim() is best effort, it should return when
these data are not yet allocated.
This patch also fixes potential null pointer access in
mem_cgroup_remove_from_trees() and mem_cgroup_update_tree().
Link: http://lkml.kernel.org/r/1487856999-16581-2-git-send-email-ldufour@linux.vnet.ibm.com
Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 13583c3d3224508582ec03d881d0b68dd3ee8e10 upstream.
Creating a lot of cgroups at the same time might stall all worker
threads with kmem cache creation works, because kmem cache creation is
done with the slab_mutex held. The problem was amplified by commits
801faf0db894 ("mm/slab: lockless decision to grow cache") in case of
SLAB and 81ae6d03952c ("mm/slub.c: replace kick_all_cpus_sync() with
synchronize_sched() in kmem_cache_shrink()") in case of SLUB, which
increased the maximal time the slab_mutex can be held.
To prevent that from happening, let's use a special ordered single
threaded workqueue for kmem cache creation. This shouldn't introduce
any functional changes regarding how kmem caches are created, as the
work function holds the global slab_mutex during its whole runtime
anyway, making it impossible to run more than one work at a time. By
using a single threaded workqueue, we just avoid creating a thread per
each work. Ordering is required to avoid a situation when a cgroup's
work is put off indefinitely because there are other cgroups to serve,
in other words to guarantee fairness.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=172981
Link: http://lkml.kernel.org/r/20161004131417.GC1862@esperanza
Signed-off-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Reported-by: Doug Smythies <dsmythies@telus.net>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 40e952f9d687928b32db20226f085ae660a7237c upstream.
mem_cgroup_free() indirectly calls wb_domain_exit() which is not
prepared to deal with a struct wb_domain object that hasn't executed
wb_domain_init(). For instance, the following warning message is
printed by lockdep if alloc_percpu() fails in mem_cgroup_alloc():
INFO: trying to register non-static key.
the code is fine but needs lockdep annotation.
turning off the locking correctness validator.
CPU: 1 PID: 1950 Comm: mkdir Not tainted 4.10.0+ #151
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
Call Trace:
dump_stack+0x67/0x99
register_lock_class+0x36d/0x540
__lock_acquire+0x7f/0x1a30
lock_acquire+0xcc/0x200
del_timer_sync+0x3c/0xc0
wb_domain_exit+0x14/0x20
mem_cgroup_free+0x14/0x40
mem_cgroup_css_alloc+0x3f9/0x620
cgroup_apply_control_enable+0x190/0x390
cgroup_mkdir+0x290/0x3d0
kernfs_iop_mkdir+0x58/0x80
vfs_mkdir+0x10e/0x1a0
SyS_mkdirat+0xa8/0xd0
SyS_mkdir+0x14/0x20
entry_SYSCALL_64_fastpath+0x18/0xad
Add __mem_cgroup_free() which skips wb_domain_exit(). This is used by
both mem_cgroup_free() and mem_cgroup_alloc() clean up.
Fixes: 0b8f73e104285 ("mm: memcontrol: clean up alloc, online, offline, free functions")
Link: http://lkml.kernel.org/r/20170306192122.24262-1-tahsin@google.com
Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.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>
commit 3674534b775354516e5c148ea48f51d4d1909a78 upstream.
When memory.move_charge_at_immigrate is enabled and precharges are
depleted during move, mem_cgroup_move_charge_pte_range() will attempt to
increase the size of the precharge.
Prevent precharges from ever looping by setting __GFP_NORETRY. This was
probably the intention of the GFP_KERNEL & ~__GFP_NORETRY, which is
pointless as written.
Fixes: 0029e19ebf84 ("mm: memcontrol: remove explicit OOM parameter in charge path")
Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1701130208510.69402@chino.kir.corp.google.com
Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.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>
commit b4536f0c829c8586544c94735c343f9b5070bd01 upstream.
Nils Holland and Klaus Ethgen have reported unexpected OOM killer
invocations with 32b kernel starting with 4.8 kernels
kworker/u4:5 invoked oom-killer: gfp_mask=0x2400840(GFP_NOFS|__GFP_NOFAIL), nodemask=0, order=0, oom_score_adj=0
kworker/u4:5 cpuset=/ mems_allowed=0
CPU: 1 PID: 2603 Comm: kworker/u4:5 Not tainted 4.9.0-gentoo #2
[...]
Mem-Info:
active_anon:58685 inactive_anon:90 isolated_anon:0
active_file:274324 inactive_file:281962 isolated_file:0
unevictable:0 dirty:649 writeback:0 unstable:0
slab_reclaimable:40662 slab_unreclaimable:17754
mapped:7382 shmem:202 pagetables:351 bounce:0
free:206736 free_pcp:332 free_cma:0
Node 0 active_anon:234740kB inactive_anon:360kB active_file:1097296kB inactive_file:1127848kB unevictable:0kB isolated(anon):0kB isolated(file):0kB mapped:29528kB dirty:2596kB writeback:0kB shmem:0kB shmem_thp: 0kB shmem_pmdmapped: 184320kB anon_thp: 808kB writeback_tmp:0kB unstable:0kB pages_scanned:0 all_unreclaimable? no
DMA free:3952kB min:788kB low:984kB high:1180kB active_anon:0kB inactive_anon:0kB active_file:7316kB inactive_file:0kB unevictable:0kB writepending:96kB present:15992kB managed:15916kB mlocked:0kB slab_reclaimable:3200kB slab_unreclaimable:1408kB kernel_stack:0kB pagetables:0kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB
lowmem_reserve[]: 0 813 3474 3474
Normal free:41332kB min:41368kB low:51708kB high:62048kB active_anon:0kB inactive_anon:0kB active_file:532748kB inactive_file:44kB unevictable:0kB writepending:24kB present:897016kB managed:836248kB mlocked:0kB slab_reclaimable:159448kB slab_unreclaimable:69608kB kernel_stack:1112kB pagetables:1404kB bounce:0kB free_pcp:528kB local_pcp:340kB free_cma:0kB
lowmem_reserve[]: 0 0 21292 21292
HighMem free:781660kB min:512kB low:34356kB high:68200kB active_anon:234740kB inactive_anon:360kB active_file:557232kB inactive_file:1127804kB unevictable:0kB writepending:2592kB present:2725384kB managed:2725384kB mlocked:0kB slab_reclaimable:0kB slab_unreclaimable:0kB kernel_stack:0kB pagetables:0kB bounce:0kB free_pcp:800kB local_pcp:608kB free_cma:0kB
the oom killer is clearly pre-mature because there there is still a lot
of page cache in the zone Normal which should satisfy this lowmem
request. Further debugging has shown that the reclaim cannot make any
forward progress because the page cache is hidden in the active list
which doesn't get rotated because inactive_list_is_low is not memcg
aware.
The code simply subtracts per-zone highmem counters from the respective
memcg's lru sizes which doesn't make any sense. We can simply end up
always seeing the resulting active and inactive counts 0 and return
false. This issue is not limited to 32b kernels but in practice the
effect on systems without CONFIG_HIGHMEM would be much harder to notice
because we do not invoke the OOM killer for allocations requests
targeting < ZONE_NORMAL.
Fix the issue by tracking per zone lru page counts in mem_cgroup_per_node
and subtract per-memcg highmem counts when memcg is enabled. Introduce
helper lruvec_zone_lru_size which redirects to either zone counters or
mem_cgroup_get_zone_lru_size when appropriate.
We are losing empty LRU but non-zero lru size detection introduced by
ca707239e8a7 ("mm: update_lru_size warn and reset bad lru_size") because
of the inherent zone vs. node discrepancy.
Fixes: f8d1a31163fc ("mm: consider whether to decivate based on eligible zones inactive ratio")
Link: http://lkml.kernel.org/r/20170104100825.3729-1-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Nils Holland <nholland@tisys.org>
Tested-by: Nils Holland <nholland@tisys.org>
Reported-by: Klaus Ethgen <Klaus@Ethgen.de>
Acked-by: Minchan Kim <minchan@kernel.org>
Acked-by: Mel Gorman <mgorman@suse.de>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Vladimir Davydov <vdavydov.dev@gmail.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>
On 4.0, we saw a stack corruption from a page fault entering direct
memory cgroup reclaim, calling into btrfs_releasepage(), which then
tried to allocate an extent and recursed back into a kmem charge ad
nauseam:
[...]
btrfs_releasepage+0x2c/0x30
try_to_release_page+0x32/0x50
shrink_page_list+0x6da/0x7a0
shrink_inactive_list+0x1e5/0x510
shrink_lruvec+0x605/0x7f0
shrink_zone+0xee/0x320
do_try_to_free_pages+0x174/0x440
try_to_free_mem_cgroup_pages+0xa7/0x130
try_charge+0x17b/0x830
memcg_charge_kmem+0x40/0x80
new_slab+0x2d9/0x5a0
__slab_alloc+0x2fd/0x44f
kmem_cache_alloc+0x193/0x1e0
alloc_extent_state+0x21/0xc0
__clear_extent_bit+0x2b5/0x400
try_release_extent_mapping+0x1a3/0x220
__btrfs_releasepage+0x31/0x70
btrfs_releasepage+0x2c/0x30
try_to_release_page+0x32/0x50
shrink_page_list+0x6da/0x7a0
shrink_inactive_list+0x1e5/0x510
shrink_lruvec+0x605/0x7f0
shrink_zone+0xee/0x320
do_try_to_free_pages+0x174/0x440
try_to_free_mem_cgroup_pages+0xa7/0x130
try_charge+0x17b/0x830
mem_cgroup_try_charge+0x65/0x1c0
handle_mm_fault+0x117f/0x1510
__do_page_fault+0x177/0x420
do_page_fault+0xc/0x10
page_fault+0x22/0x30
On later kernels, kmem charging is opt-in rather than opt-out, and that
particular kmem allocation in btrfs_releasepage() is no longer being
charged and won't recurse and overrun the stack anymore.
But it's not impossible for an accounted allocation to happen from the
memcg direct reclaim context, and we needed to reproduce this crash many
times before we even got a useful stack trace out of it.
Like other direct reclaimers, mark tasks in memcg reclaim PF_MEMALLOC to
avoid recursing into any other form of direct reclaim. Then let
recursive charges from PF_MEMALLOC contexts bypass the cgroup limit.
Link: http://lkml.kernel.org/r/20161025141050.GA13019@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The cgroup core and the memory controller need to track socket ownership
for different purposes, but the tracking sites being entirely different
is kind of ugly.
Be a better citizen and rename the memory controller callbacks to match
the cgroup core callbacks, then move them to the same place.
[akpm@linux-foundation.org: coding-style fixes]
Link: http://lkml.kernel.org/r/20160914194846.11153-3-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Vladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch is to improve the performance of swap cache operations when
the type of the swap device is not 0. Originally, the whole swap entry
value is used as the key of the swap cache, even though there is one
radix tree for each swap device. If the type of the swap device is not
0, the height of the radix tree of the swap cache will be increased
unnecessary, especially on 64bit architecture. For example, for a 1GB
swap device on the x86_64 architecture, the height of the radix tree of
the swap cache is 11. But if the offset of the swap entry is used as
the key of the swap cache, the height of the radix tree of the swap
cache is 4. The increased height causes unnecessary radix tree
descending and increased cache footprint.
This patch reduces the height of the radix tree of the swap cache via
using the offset of the swap entry instead of the whole swap entry value
as the key of the swap cache. In 32 processes sequential swap out test
case on a Xeon E5 v3 system with RAM disk as swap, the lock contention
for the spinlock of the swap cache is reduced from 20.15% to 12.19%,
when the type of the swap device is 1.
Use the whole swap entry as key,
perf-profile.calltrace.cycles-pp._raw_spin_lock_irq.__add_to_swap_cache.add_to_swap_cache.add_to_swap.shrink_page_list: 10.37,
perf-profile.calltrace.cycles-pp._raw_spin_lock_irqsave.__remove_mapping.shrink_page_list.shrink_inactive_list.shrink_node_memcg: 9.78,
Use the swap offset as key,
perf-profile.calltrace.cycles-pp._raw_spin_lock_irq.__add_to_swap_cache.add_to_swap_cache.add_to_swap.shrink_page_list: 6.25,
perf-profile.calltrace.cycles-pp._raw_spin_lock_irqsave.__remove_mapping.shrink_page_list.shrink_inactive_list.shrink_node_memcg: 5.94,
Link: http://lkml.kernel.org/r/1473270649-27229-1-git-send-email-ying.huang@intel.com
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Aaron Lu <aaron.lu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mem_cgroup_count_precharge() and mem_cgroup_move_charge() both call
walk_page_range() on the range 0 to ~0UL, neither provide a pte_hole
callback, which causes the current implementation to skip non-vma
regions. This is all fine but follow up changes would like to make
walk_page_range more generic so it is better to be explicit about which
range to traverse so let's use highest_vm_end to explicitly traverse
only user mmaped memory.
[mhocko@kernel.org: rewrote changelog]
Link: http://lkml.kernel.org/r/1472655897-22532-1-git-send-email-james.morse@arm.com
Signed-off-by: James Morse <james.morse@arm.com>
Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When selecting an oom victim, we use the same heuristic for both memory
cgroup and global oom. The only difference is the scope of tasks to
select the victim from. So we could just export an iterator over all
memcg tasks and keep all oom related logic in oom_kill.c, but instead we
duplicate pieces of it in memcontrol.c reusing some initially private
functions of oom_kill.c in order to not duplicate all of it. That looks
ugly and error prone, because any modification of select_bad_process
should also be propagated to mem_cgroup_out_of_memory.
Let's rework this as follows: keep all oom heuristic related code private
to oom_kill.c and make oom_kill.c use exported memcg functions when it's
really necessary (like in case of iterating over memcg tasks).
Link: http://lkml.kernel.org/r/1470056933-7505-1-git-send-email-vdavydov@virtuozzo.com
Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
During cgroup2 rollout into production, we started encountering css
refcount underflows and css access crashes in the memory controller.
Splitting the heavily shared css reference counter into logical users
narrowed the imbalance down to the cgroup2 socket memory accounting.
The problem turns out to be the per-cpu charge cache. Cgroup1 had a
separate socket counter, but the new cgroup2 socket accounting goes
through the common charge path that uses a shared per-cpu cache for all
memory that is being tracked. Those caches are safe against scheduling
preemption, but not against interrupts - such as the newly added packet
receive path. When cache draining is interrupted by network RX taking
pages out of the cache, the resuming drain operation will put references
of in-use pages, thus causing the imbalance.
Disable IRQs during all per-cpu charge cache operations.
Fixes: f7e1cb6ec51b ("mm: memcontrol: account socket memory in unified hierarchy memory controller")
Link: http://lkml.kernel.org/r/20160914194846.11153-1-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Vladimir Davydov <vdavydov@virtuozzo.com>
Cc: <stable@vger.kernel.org> [4.5+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A bugfix in v4.8-rc2 introduced a harmless warning when
CONFIG_MEMCG_SWAP is disabled but CONFIG_MEMCG is enabled:
mm/memcontrol.c:4085:27: error: 'mem_cgroup_id_get_online' defined but not used [-Werror=unused-function]
static struct mem_cgroup *mem_cgroup_id_get_online(struct mem_cgroup *memcg)
This moves the function inside of the #ifdef block that hides the
calling function, to avoid the warning.
Fixes: 1f47b61fb407 ("mm: memcontrol: fix swap counter leak on swapout from offline cgroup")
Link: http://lkml.kernel.org/r/20160824113733.2776701-1-arnd@arndb.de
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since commit 73f576c04b94 ("mm: memcontrol: fix cgroup creation failure
after many small jobs") swap entries do not pin memcg->css.refcnt
directly. Instead, they pin memcg->id.ref. So we should adjust the
reference counters accordingly when moving swap charges between cgroups.
Fixes: 73f576c04b941 ("mm: memcontrol: fix cgroup creation failure after many small jobs")
Link: http://lkml.kernel.org/r/9ce297c64954a42dc90b543bc76106c4a94f07e8.1470219853.git.vdavydov@virtuozzo.com
Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: <stable@vger.kernel.org> [3.19+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
An offline memory cgroup might have anonymous memory or shmem left
charged to it and no swap. Since only swap entries pin the id of an
offline cgroup, such a cgroup will have no id and so an attempt to
swapout its anon/shmem will not store memory cgroup info in the swap
cgroup map. As a result, memcg->swap or memcg->memsw will never get
uncharged from it and any of its ascendants.
Fix this by always charging swapout to the first ancestor cgroup that
hasn't released its id yet.
[hannes@cmpxchg.org: add comment to mem_cgroup_swapout]
[vdavydov@virtuozzo.com: use WARN_ON_ONCE() in mem_cgroup_id_get_online()]
Link: http://lkml.kernel.org/r/20160803123445.GJ13263@esperanza
Fixes: 73f576c04b941 ("mm: memcontrol: fix cgroup creation failure after many small jobs")
Link: http://lkml.kernel.org/r/5336daa5c9a32e776067773d9da655d2dc126491.1470219853.git.vdavydov@virtuozzo.com
Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: <stable@vger.kernel.org> [3.19+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
To distinguish non-slab pages charged to kmemcg we mark them PageKmemcg,
which sets page->_mapcount to -512. Currently, we set/clear PageKmemcg
in __alloc_pages_nodemask()/free_pages_prepare() for any page allocated
with __GFP_ACCOUNT, including those that aren't actually charged to any
cgroup, i.e. allocated from the root cgroup context. To avoid overhead
in case cgroups are not used, we only do that if memcg_kmem_enabled() is
true. The latter is set iff there are kmem-enabled memory cgroups
(online or offline). The root cgroup is not considered kmem-enabled.
As a result, if a page is allocated with __GFP_ACCOUNT for the root
cgroup when there are kmem-enabled memory cgroups and is freed after all
kmem-enabled memory cgroups were removed, e.g.
# no memory cgroups has been created yet, create one
mkdir /sys/fs/cgroup/memory/test
# run something allocating pages with __GFP_ACCOUNT, e.g.
# a program using pipe
dmesg | tail
# remove the memory cgroup
rmdir /sys/fs/cgroup/memory/test
we'll get bad page state bug complaining about page->_mapcount != -1:
BUG: Bad page state in process swapper/0 pfn:1fd945c
page:ffffea007f651700 count:0 mapcount:-511 mapping: (null) index:0x0
flags: 0x1000000000000000()
To avoid that, let's mark with PageKmemcg only those pages that are
actually charged to and hence pin a non-root memory cgroup.
Fixes: 4949148ad433 ("mm: charge/uncharge kmemcg from generic page allocator paths")
Reported-and-tested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We've had a report about soft lockups caused by lock bouncing in the
soft reclaim path:
BUG: soft lockup - CPU#0 stuck for 22s! [kav4proxy-kavic:3128]
RIP: 0010:[<ffffffff81469798>] [<ffffffff81469798>] _raw_spin_lock+0x18/0x20
Call Trace:
mem_cgroup_soft_limit_reclaim+0x25a/0x280
shrink_zones+0xed/0x200
do_try_to_free_pages+0x74/0x320
try_to_free_pages+0x112/0x180
__alloc_pages_slowpath+0x3ff/0x820
__alloc_pages_nodemask+0x1e9/0x200
alloc_pages_vma+0xe1/0x290
do_wp_page+0x19f/0x840
handle_pte_fault+0x1cd/0x230
do_page_fault+0x1fd/0x4c0
page_fault+0x25/0x30
There are no memcgs created so there cannot be any in the soft limit
excess obviously:
[...]
memory 0 1 1
so all this just seems to be mem_cgroup_largest_soft_limit_node trying
to get spin_lock_irq(&mctz->lock) just to find out that the soft limit
excess tree is empty. This is just pointless wasting of cycles and
cache line bouncing during heavy parallel reclaim on large machines.
The particular machine wasn't very healthy and most probably suffering
from a memory leak which just caused the memory reclaim to trash
heavily. But bouncing on the lock certainly didn't help...
Fix this by optimistic lockless check and bail out early if the tree is
empty. This is theoretically racy but that shouldn't matter all that
much. First of all soft limit is a best effort feature and it is slowly
getting deprecated and its usage should be really scarce. Bouncing on a
lock without a good reason is surely much bigger problem, especially on
large CPU machines.
Link: http://lkml.kernel.org/r/1470073277-1056-1-git-send-email-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We should account for stacks regardless of stack size, and we need to
account in sub-page units if THREAD_SIZE < PAGE_SIZE. Change the units
to kilobytes and Move it into account_kernel_stack().
Fixes: 12580e4b54ba8 ("mm: memcontrol: report kernel stack usage in cgroup2 memory.stat")
Link: http://lkml.kernel.org/r/9b5314e3ee5eda61b0317ec1563768602c1ef438.1468523549.git.luto@kernel.org
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Reviewed-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Minchan Kim reported setting the following warning on a 32-bit system
although it can affect 64-bit systems.
WARNING: CPU: 4 PID: 1322 at mm/memcontrol.c:998 mem_cgroup_update_lru_size+0x103/0x110
mem_cgroup_update_lru_size(f44b4000, 1, -7): zid 1 lru_size 1 but empty
Modules linked in:
CPU: 4 PID: 1322 Comm: cp Not tainted 4.7.0-rc4-mm1+ #143
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
Call Trace:
dump_stack+0x76/0xaf
__warn+0xea/0x110
? mem_cgroup_update_lru_size+0x103/0x110
warn_slowpath_fmt+0x3b/0x40
mem_cgroup_update_lru_size+0x103/0x110
isolate_lru_pages.isra.61+0x2e2/0x360
shrink_active_list+0xac/0x2a0
? __delay+0xe/0x10
shrink_node_memcg+0x53c/0x7a0
shrink_node+0xab/0x2a0
do_try_to_free_pages+0xc6/0x390
try_to_free_pages+0x245/0x590
LRU list contents and counts are updated separately. Counts are updated
before pages are added to the LRU and updated after pages are removed.
The warning above is from a check in mem_cgroup_update_lru_size that
ensures that list sizes of zero are empty.
The problem is that node-lru needs to account for highmem pages if
CONFIG_HIGHMEM is set. One impact of the implementation is that the
sizes are updated in multiple passes when pages from multiple zones were
isolated. This happens whether HIGHMEM is set or not. When multiple
zones are isolated, it's possible for a debugging check in memcg to be
tripped.
This patch forces all the zone counts to be updated before the memcg
function is called.
Link: http://lkml.kernel.org/r/1468588165-12461-6-git-send-email-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Tested-by: Minchan Kim <minchan@kernel.org>
Reported-by: Minchan Kim <minchan@kernel.org>
Acked-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Memcg needs adjustment after moving LRUs to the node. Limits are
tracked per memcg but the soft-limit excess is tracked per zone. As
global page reclaim is based on the node, it is easy to imagine a
situation where a zone soft limit is exceeded even though the memcg
limit is fine.
This patch moves the soft limit tree the node. Technically, all the
variable names should also change but people are already familiar by the
meaning of "mz" even if "mn" would be a more appropriate name now.
Link: http://lkml.kernel.org/r/1467970510-21195-15-git-send-email-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Earlier patches focused on having direct reclaim and kswapd use data
that is node-centric for reclaiming but shrink_node() itself still uses
too much zone information. This patch removes unnecessary zone-based
information with the most important decision being whether to continue
reclaim or not. Some memcg APIs are adjusted as a result even though
memcg itself still uses some zone information.
[mgorman@techsingularity.net: optimization]
Link: http://lkml.kernel.org/r/1468588165-12461-2-git-send-email-mgorman@techsingularity.net
Link: http://lkml.kernel.org/r/1467970510-21195-14-git-send-email-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This moves the LRU lists from the zone to the node and related data such
as counters, tracing, congestion tracking and writeback tracking.
Unfortunately, due to reclaim and compaction retry logic, it is
necessary to account for the number of LRU pages on both zone and node
logic. Most reclaim logic is based on the node counters but the retry
logic uses the zone counters which do not distinguish inactive and
active sizes. It would be possible to leave the LRU counters on a
per-zone basis but it's a heavier calculation across multiple cache
lines that is much more frequent than the retry checks.
Other than the LRU counters, this is mostly a mechanical patch but note
that it introduces a number of anomalies. For example, the scans are
per-zone but using per-node counters. We also mark a node as congested
when a zone is congested. This causes weird problems that are fixed
later but is easier to review.
In the event that there is excessive overhead on 32-bit systems due to
the nodes being on LRU then there are two potential solutions
1. Long-term isolation of highmem pages when reclaim is lowmem
When pages are skipped, they are immediately added back onto the LRU
list. If lowmem reclaim persisted for long periods of time, the same
highmem pages get continually scanned. The idea would be that lowmem
keeps those pages on a separate list until a reclaim for highmem pages
arrives that splices the highmem pages back onto the LRU. It potentially
could be implemented similar to the UNEVICTABLE list.
That would reduce the skip rate with the potential corner case is that
highmem pages have to be scanned and reclaimed to free lowmem slab pages.
2. Linear scan lowmem pages if the initial LRU shrink fails
This will break LRU ordering but may be preferable and faster during
memory pressure than skipping LRU pages.
Link: http://lkml.kernel.org/r/1467970510-21195-4-git-send-email-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Node-based reclaim requires node-based LRUs and locking. This is a
preparation patch that just moves the lru_lock to the node so later
patches are easier to review. It is a mechanical change but note this
patch makes contention worse because the LRU lock is hotter and direct
reclaim and kswapd can contend on the same lock even when reclaiming
from different zones.
Link: http://lkml.kernel.org/r/1467970510-21195-3-git-send-email-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Minchan Kim <minchan@kernel.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 23047a96d7cf ("mm: workingset: per-cgroup cache thrash
detection") added a page->mem_cgroup lookup to the cache eviction,
refault, and activation paths, as well as locking to the activation
path, and the vm-scalability tests showed a regression of -23%.
While the test in question is an artificial worst-case scenario that
doesn't occur in real workloads - reading two sparse files in parallel
at full CPU speed just to hammer the LRU paths - there is still some
optimizations that can be done in those paths.
Inline the lookup functions to eliminate calls. Also, page->mem_cgroup
doesn't need to be stabilized when counting an activation; we merely
need to hold the RCU lock to prevent the memcg from being freed.
This cuts down on overhead quite a bit:
23047a96d7cfcfca 063f6715e77a7be5770d6081fe
---------------- --------------------------
%stddev %change %stddev
\ | \
21621405 +- 0% +11.3% 24069657 +- 2% vm-scalability.throughput
[linux@roeck-us.net: drop unnecessary include file]
[hannes@cmpxchg.org: add WARN_ON_ONCE()s]
Link: http://lkml.kernel.org/r/20160707194024.GA26580@cmpxchg.org
Link: http://lkml.kernel.org/r/20160624175101.GA3024@cmpxchg.org
Reported-by: Ye Xiaolong <xiaolong.ye@intel.com>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Vladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
task_will_free_mem is rather weak. It doesn't really tell whether the
task has chance to drop its mm. 98748bd72200 ("oom: consider
multi-threaded tasks in task_will_free_mem") made a first step into making
it more robust for multi-threaded applications so now we know that the
whole process is going down and probably drop the mm.
This patch builds on top for more complex scenarios where mm is shared
between different processes - CLONE_VM without CLONE_SIGHAND, or in kernel
use_mm().
Make sure that all processes sharing the mm are killed or exiting. This
will allow us to replace try_oom_reaper by wake_oom_reaper because
task_will_free_mem implies the task is reapable now. Therefore all paths
which bypass the oom killer are now reapable and so they shouldn't lock up
the oom killer.
Link: http://lkml.kernel.org/r/1466426628-15074-8-git-send-email-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Vladimir Davydov <vdavydov@virtuozzo.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit f627c2f53786 ("memcg: adjust to support new THP refcounting")
adds a compound parameter for several functions, and change one as
compound for mem_cgroup_move_account but it does not change the
comments.
Link: http://lkml.kernel.org/r/1465368216-9393-1-git-send-email-roy.qing.li@gmail.com
Signed-off-by: Li RongQing <roy.qing.li@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When calling uncharge_list, if a page is transparent huge we don't need
to BUG_ON about non-transparent huge, since nobody should be able to see
the page at this stage and this page cannot be raced against with a THP
split.
This check became unneeded after 0a31bc97c80c ("mm: memcontrol: rewrite
uncharge API").
[mhocko@suse.com: changelog enhancements]
Link: http://lkml.kernel.org/r/1465369248-13865-1-git-send-email-roy.qing.li@gmail.com
Signed-off-by: Li RongQing <roy.qing.li@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
oom_scan_process_thread() does not use totalpages argument.
oom_badness() uses it.
Link: http://lkml.kernel.org/r/1463796041-7889-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Page table pages are batched-freed in release_pages on most
architectures. If we want to charge them to kmemcg (this is what is
done later in this series), we need to teach mem_cgroup_uncharge_list to
handle kmem pages.
Link: http://lkml.kernel.org/r/18d5c09e97f80074ed25b97a7d0f32b95d875717.1464079538.git.vdavydov@virtuozzo.com
Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- Handle memcg_kmem_enabled check out to the caller. This reduces the
number of function definitions making the code easier to follow. At
the same time it doesn't result in code bloat, because all of these
functions are used only in one or two places.
- Move __GFP_ACCOUNT check to the caller as well so that one wouldn't
have to dive deep into memcg implementation to see which allocations
are charged and which are not.
- Refresh comments.
Link: http://lkml.kernel.org/r/52882a28b542c1979fd9a033b4dc8637fc347399.1464079537.git.vdavydov@virtuozzo.com
Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It's a part of oom context just like allocation order and nodemask, so
let's move it to oom_control instead of passing it in the argument list.
Link: http://lkml.kernel.org/r/40e03fd7aaf1f55c75d787128d6d17c5a71226c2.1464358556.git.vdavydov@virtuozzo.com
Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It seems like this parameter has never been used since being introduced
by 90254a65833b ("memcg: clean up move charge"). Not a big deal because
I assume the function would get inlined into the caller anyway but why
not get rid of it.
[mhocko@suse.com: wrote changelog]
Link: http://lkml.kernel.org/r/20160525151831.GJ20132@dhcp22.suse.cz
Link: http://lkml.kernel.org/r/1464145026-26693-1-git-send-email-roy.qing.li@gmail.com
Signed-off-by: Li RongQing <roy.qing.li@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The memory controller has quite a bit of state that usually outlives the
cgroup and pins its CSS until said state disappears. At the same time
it imposes a 16-bit limit on the CSS ID space to economically store IDs
in the wild. Consequently, when we use cgroups to contain frequent but
small and short-lived jobs that leave behind some page cache, we quickly
run into the 64k limitations of outstanding CSSs. Creating a new cgroup
fails with -ENOSPC while there are only a few, or even no user-visible
cgroups in existence.
Although pinning CSSs past cgroup removal is common, there are only two
instances that actually need an ID after a cgroup is deleted: cache
shadow entries and swapout records.
Cache shadow entries reference the ID weakly and can deal with the CSS
having disappeared when it's looked up later. They pose no hurdle.
Swap-out records do need to pin the css to hierarchically attribute
swapins after the cgroup has been deleted; though the only pages that
remain swapped out after offlining are tmpfs/shmem pages. And those
references are under the user's control, so they are manageable.
This patch introduces a private 16-bit memcg ID and switches swap and
cache shadow entries over to using that. This ID can then be recycled
after offlining when the CSS remains pinned only by objects that don't
specifically need it.
This script demonstrates the problem by faulting one cache page in a new
cgroup and deleting it again:
set -e
mkdir -p pages
for x in `seq 128000`; do
[ $((x % 1000)) -eq 0 ] && echo $x
mkdir /cgroup/foo
echo $$ >/cgroup/foo/cgroup.procs
echo trex >pages/$x
echo $$ >/cgroup/cgroup.procs
rmdir /cgroup/foo
done
When run on an unpatched kernel, we eventually run out of possible IDs
even though there are no visible cgroups:
[root@ham ~]# ./cssidstress.sh
[...]
65000
mkdir: cannot create directory '/cgroup/foo': No space left on device
After this patch, the IDs get released upon cgroup destruction and the
cache and css objects get released once memory reclaim kicks in.
[hannes@cmpxchg.org: init the IDR]
Link: http://lkml.kernel.org/r/20160621154601.GA22431@cmpxchg.org
Fixes: b2052564e66d ("mm: memcontrol: continue cache reclaim from offlined groups")
Link: http://lkml.kernel.org/r/20160617162516.GD19084@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: John Garcia <john.garcia@mesosphere.io>
Reviewed-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Nikolay Borisov <kernel@kyup.com>
Cc: <stable@vger.kernel.org> [3.19+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Revert commit 1383399d7be0 ("mm: memcontrol: fix possible css ref leak
on oom"). Johannes points out "There is a task_in_memcg_oom() check
before calling mem_cgroup_oom()".
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
memcg_offline_kmem() may be called from memcg_free_kmem() after a css
init failure. memcg_free_kmem() is a ->css_free callback which is
called without cgroup_mutex and memcg_offline_kmem() ends up using
css_for_each_descendant_pre() without any locking. Fix it by adding rcu
read locking around it.
mkdir: cannot create directory `65530': No space left on device
===============================
[ INFO: suspicious RCU usage. ]
4.6.0-work+ #321 Not tainted
-------------------------------
kernel/cgroup.c:4008 cgroup_mutex or RCU read lock required!
[ 527.243970] other info that might help us debug this:
[ 527.244715]
rcu_scheduler_active = 1, debug_locks = 0
2 locks held by kworker/0:5/1664:
#0: ("cgroup_destroy"){.+.+..}, at: [<ffffffff81060ab5>] process_one_work+0x165/0x4a0
#1: ((&css->destroy_work)#3){+.+...}, at: [<ffffffff81060ab5>] process_one_work+0x165/0x4a0
[ 527.248098] stack backtrace:
CPU: 0 PID: 1664 Comm: kworker/0:5 Not tainted 4.6.0-work+ #321
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.1-1.fc24 04/01/2014
Workqueue: cgroup_destroy css_free_work_fn
Call Trace:
dump_stack+0x68/0xa1
lockdep_rcu_suspicious+0xd7/0x110
css_next_descendant_pre+0x7d/0xb0
memcg_offline_kmem.part.44+0x4a/0xc0
mem_cgroup_css_free+0x1ec/0x200
css_free_work_fn+0x49/0x5e0
process_one_work+0x1c5/0x4a0
worker_thread+0x49/0x490
kthread+0xea/0x100
ret_from_fork+0x1f/0x40
Link: http://lkml.kernel.org/r/20160526203018.GG23194@mtj.duckdns.org
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: <stable@vger.kernel.org> [4.5+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Move the comments for get_mctgt_type() to be before get_mctgt_type()
implementation.
Link: http://lkml.kernel.org/r/1463644638-7446-1-git-send-email-roy.qing.li@gmail.com
Signed-off-by: Li RongQing <roy.qing.li@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mem_cgroup_margin() might return (memory.limit - memory_count) when the
memsw.limit is in excess. This doesn't happen usually because we do not
allow excess on hard limits and (memory.limit <= memsw.limit), but
__GFP_NOFAIL charges can force the charge and cause the excess when no
memory is really swappable (swap is full or no anonymous memory is
left).
[mhocko@suse.com: rewrote changelog]
Link: http://lkml.kernel.org/r/20160525155122.GK20132@dhcp22.suse.cz
Link: http://lkml.kernel.org/r/1464068266-27736-1-git-send-email-roy.qing.li@gmail.com
Signed-off-by: Li RongQing <roy.qing.li@gmail.com>
Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mem_cgroup_out_of_memory() is returning "true" if it finds a TIF_MEMDIE
task after an eligible task was found, "false" if it found a TIF_MEMDIE
task before an eligible task is found.
This difference confuses memory_max_write() which checks the return
value of mem_cgroup_out_of_memory(). Since memory_max_write() wants to
continue looping, mem_cgroup_out_of_memory() should return "true" in
this case.
This patch sets a dummy pointer in order to return "true".
Link: http://lkml.kernel.org/r/1463753327-5170-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mem_cgroup_oom may be invoked multiple times while a process is handling
a page fault, in which case current->memcg_in_oom will be overwritten
leaking the previously taken css reference.
Link: http://lkml.kernel.org/r/1464019330-7579-1-git-send-email-vdavydov@virtuozzo.com
Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit f61c42a7d911 ("memcg: remove tasks/children test from
mem_cgroup_force_empty()") removed memory reparenting from the function.
Fix the function's comment.
Link: http://lkml.kernel.org/r/1462569810-54496-1-git-send-email-gthelen@google.com
Signed-off-by: Greg Thelen <gthelen@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Vladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Chunguang Xu
Shakeel Butt
Roman Gushchin
Michal Hocko
Miles Chen
Kirill Tkhai
Jing Xia
Laurent Dufour
Vladimir Davydov
Tahsin Erdogan
David Rientjes
Johannes Weiner
Huang Ying
James Morse
Vladimir Davydov
Johannes Weiner
Arnd Bergmann
Andy Lutomirski
Mel Gorman
Li RongQing
Tetsuo Handa
Tejun Heo
Andrew Morton
Greg Thelen