The patch titled
Subject: mm: memcontrol: rewrite uncharge API fix
has been removed from the -mm tree. Its filename was
mm-memcontrol-rewrite-uncharge-api-fix-6.patch
This patch was dropped because an updated version will be merged
------------------------------------------------------
From: Johannes Weiner <hannes@xxxxxxxxxxx>
Subject: mm: memcontrol: rewrite uncharge API fix
Hugh reports:
======================================================
[ INFO: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected ]
3.16.0-rc2-mm1 #3 Not tainted
------------------------------------------------------
cc1/2771 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire:
(&(&rtpz->lock)->rlock){+.+.-.}, at: [<ffffffff811518b5>] memcg_check_events+0x17e/0x206
dd
and this task is already holding:
(&(&zone->lru_lock)->rlock){..-.-.}, at: [<ffffffff8110da3f>] release_pages+0xe7/0x239
which would create a new lock dependency:
(&(&zone->lru_lock)->rlock){..-.-.} -> (&(&rtpz->lock)->rlock){+.+.-.}
but this new dependency connects a SOFTIRQ-irq-safe lock:
(&(&zone->lru_lock)->rlock){..-.-.}
... which became SOFTIRQ-irq-safe at:
[<ffffffff810c201e>] __lock_acquire+0x59f/0x17e8
[<ffffffff810c38a6>] lock_acquire+0x61/0x78
[<ffffffff815bdfbd>] _raw_spin_lock_irqsave+0x3f/0x51
[<ffffffff8110dc0e>] pagevec_lru_move_fn+0x7d/0xf6
[<ffffffff8110dca4>] pagevec_move_tail+0x1d/0x2c
[<ffffffff8110e298>] rotate_reclaimable_page+0xb2/0xd4
[<ffffffff811018bf>] end_page_writeback+0x1c/0x45
[<ffffffff81134400>] end_swap_bio_write+0x5c/0x69
[<ffffffff8123473e>] bio_endio+0x50/0x6e
[<ffffffff81238dee>] blk_update_request+0x163/0x255
[<ffffffff81238ef7>] blk_update_bidi_request+0x17/0x65
[<ffffffff81239242>] blk_end_bidi_request+0x1a/0x56
[<ffffffff81239289>] blk_end_request+0xb/0xd
[<ffffffff813a075a>] scsi_io_completion+0x16d/0x553
[<ffffffff81399c0f>] scsi_finish_command+0xb6/0xbf
[<ffffffff813a0564>] scsi_softirq_done+0xe9/0xf0
[<ffffffff8123e8e5>] blk_done_softirq+0x79/0x8b
[<ffffffff81088675>] __do_softirq+0xfc/0x21f
[<ffffffff8108898f>] irq_exit+0x3d/0x92
[<ffffffff81032379>] do_IRQ+0xcc/0xe5
[<ffffffff815bf5ac>] ret_from_intr+0x0/0x13
[<ffffffff81443ac0>] cpuidle_enter+0x12/0x14
[<ffffffff810bb4e4>] cpu_startup_entry+0x187/0x243
[<ffffffff815a90ab>] rest_init+0x12f/0x133
[<ffffffff81970e7c>] start_kernel+0x396/0x3a3
[<ffffffff81970489>] x86_64_start_reservations+0x2a/0x2c
[<ffffffff81970552>] x86_64_start_kernel+0xc7/0xca
to a SOFTIRQ-irq-unsafe lock:
(&(&rtpz->lock)->rlock){+.+.-.}
... which became SOFTIRQ-irq-unsafe at:
... [<ffffffff810c2095>] __lock_acquire+0x616/0x17e8
[<ffffffff810c38a6>] lock_acquire+0x61/0x78
[<ffffffff815bde9f>] _raw_spin_lock+0x34/0x41
[<ffffffff811518b5>] memcg_check_events+0x17e/0x206
[<ffffffff811535bb>] commit_charge+0x260/0x26f
[<ffffffff81157004>] mem_cgroup_commit_charge+0xb1/0xdb
[<ffffffff81115b51>] shmem_getpage_gfp+0x400/0x6c2
[<ffffffff81115ecc>] shmem_write_begin+0x33/0x35
[<ffffffff81102a24>] generic_perform_write+0xb7/0x1a4
[<ffffffff8110391e>] __generic_file_write_iter+0x25b/0x29b
[<ffffffff81103999>] generic_file_write_iter+0x3b/0xa5
[<ffffffff8115a115>] new_sync_write+0x7b/0x9f
[<ffffffff8115a56c>] vfs_write+0xb5/0x169
[<ffffffff8115ae1f>] SyS_write+0x45/0x8c
[<ffffffff815bead2>] system_call_fastpath+0x16/0x1b
The soft limit tree lock needs to be IRQ-safe as it's acquired while
holding the IRQ-safe zone->lru_lock.
But more importantly, with uncharge happening in release_pages() now,
this path is executed from interrupt context.
Make the soft limit tree lock, uncharge batching, and charge
statistics IRQ-safe.
Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx>
Reported-by: Hugh Dickins <hughd@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memcontrol.c | 113 +++++++++++++++++++++++++++-------------------
1 file changed, 67 insertions(+), 46 deletions(-)
diff -puN mm/memcontrol.c~mm-memcontrol-rewrite-uncharge-api-fix-6 mm/memcontrol.c
--- a/mm/memcontrol.c~mm-memcontrol-rewrite-uncharge-api-fix-6
+++ a/mm/memcontrol.c
@@ -754,9 +754,11 @@ static void __mem_cgroup_remove_exceeded
static void mem_cgroup_remove_exceeded(struct mem_cgroup_per_zone *mz,
struct mem_cgroup_tree_per_zone *mctz)
{
- spin_lock(&mctz->lock);
+ unsigned long flags;
+
+ spin_lock_irqsave(&mctz->lock, flags);
__mem_cgroup_remove_exceeded(mz, mctz);
- spin_unlock(&mctz->lock);
+ spin_unlock_irqrestore(&mctz->lock, flags);
}
@@ -779,7 +781,9 @@ static void mem_cgroup_update_tree(struc
* mem is over its softlimit.
*/
if (excess || mz->on_tree) {
- spin_lock(&mctz->lock);
+ unsigned long flags;
+
+ spin_lock_irqsave(&mctz->lock, flags);
/* if on-tree, remove it */
if (mz->on_tree)
__mem_cgroup_remove_exceeded(mz, mctz);
@@ -788,7 +792,7 @@ static void mem_cgroup_update_tree(struc
* If excess is 0, no tree ops.
*/
__mem_cgroup_insert_exceeded(mz, mctz, excess);
- spin_unlock(&mctz->lock);
+ spin_unlock_irqrestore(&mctz->lock, flags);
}
}
}
@@ -839,9 +843,9 @@ mem_cgroup_largest_soft_limit_node(struc
{
struct mem_cgroup_per_zone *mz;
- spin_lock(&mctz->lock);
+ spin_lock_irq(&mctz->lock);
mz = __mem_cgroup_largest_soft_limit_node(mctz);
- spin_unlock(&mctz->lock);
+ spin_unlock_irq(&mctz->lock);
return mz;
}
@@ -904,8 +908,9 @@ static void mem_cgroup_charge_statistics
struct page *page,
int nr_pages)
{
- preempt_disable();
+ unsigned long flags;
+ local_irq_save(flags);
/*
* Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is
* counted as CACHE even if it's on ANON LRU.
@@ -930,7 +935,7 @@ static void mem_cgroup_charge_statistics
}
__this_cpu_add(memcg->stat->nr_page_events, nr_pages);
- preempt_enable();
+ local_irq_restore(flags);
}
unsigned long mem_cgroup_get_lru_size(struct lruvec *lruvec, enum lru_list lru)
@@ -1009,7 +1014,9 @@ static bool mem_cgroup_event_ratelimit(s
*/
static void memcg_check_events(struct mem_cgroup *memcg, struct page *page)
{
- preempt_disable();
+ unsigned long flags;
+
+ local_irq_save(flags);
/* threshold event is triggered in finer grain than soft limit */
if (unlikely(mem_cgroup_event_ratelimit(memcg,
MEM_CGROUP_TARGET_THRESH))) {
@@ -1022,7 +1029,7 @@ static void memcg_check_events(struct me
do_numainfo = mem_cgroup_event_ratelimit(memcg,
MEM_CGROUP_TARGET_NUMAINFO);
#endif
- preempt_enable();
+ local_irq_restore(flags);
mem_cgroup_threshold(memcg);
if (unlikely(do_softlimit))
@@ -1032,7 +1039,7 @@ static void memcg_check_events(struct me
atomic_inc(&memcg->numainfo_events);
#endif
} else
- preempt_enable();
+ local_irq_restore(flags);
}
struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p)
@@ -3620,6 +3627,9 @@ out:
void mem_cgroup_uncharge_start(void)
{
+ unsigned long flags;
+
+ local_irq_save(flags);
current->memcg_batch.do_batch++;
/* We can do nest. */
if (current->memcg_batch.do_batch == 1) {
@@ -3627,21 +3637,18 @@ void mem_cgroup_uncharge_start(void)
current->memcg_batch.nr_pages = 0;
current->memcg_batch.memsw_nr_pages = 0;
}
+ local_irq_restore(flags);
}
void mem_cgroup_uncharge_end(void)
{
struct memcg_batch_info *batch = ¤t->memcg_batch;
+ unsigned long flags;
- if (!batch->do_batch)
- return;
-
- batch->do_batch--;
- if (batch->do_batch) /* If stacked, do nothing. */
- return;
-
- if (!batch->memcg)
- return;
+ local_irq_save(flags);
+ VM_BUG_ON(!batch->do_batch);
+ if (--batch->do_batch) /* If stacked, do nothing */
+ goto out;
/*
* This "batch->memcg" is valid without any css_get/put etc...
* bacause we hide charges behind us.
@@ -3653,8 +3660,8 @@ void mem_cgroup_uncharge_end(void)
res_counter_uncharge(&batch->memcg->memsw,
batch->memsw_nr_pages * PAGE_SIZE);
memcg_oom_recover(batch->memcg);
- /* forget this pointer (for sanity check) */
- batch->memcg = NULL;
+out:
+ local_irq_restore(flags);
}
#ifdef CONFIG_MEMCG_SWAP
@@ -6554,6 +6561,36 @@ void mem_cgroup_cancel_charge(struct pag
cancel_charge(memcg, nr_pages);
}
+static bool uncharge_batched(struct mem_cgroup *memcg,
+ unsigned long pc_flags,
+ unsigned int nr_pages)
+{
+ struct memcg_batch_info *batch = ¤t->memcg_batch;
+ bool uncharged = false;
+ unsigned long flags;
+
+ if (nr_pages > 1)
+ return false;
+ if (test_thread_flag(TIF_MEMDIE))
+ return false;
+
+ local_irq_save(flags);
+ if (!batch->do_batch)
+ goto out;
+ if (batch->memcg && batch->memcg != memcg)
+ goto out;
+ if (!batch->memcg)
+ batch->memcg = memcg;
+ if (pc_flags & PCG_MEM)
+ batch->nr_pages++;
+ if (pc_flags & PCG_MEMSW)
+ batch->memsw_nr_pages++;
+ uncharged = true;
+out:
+ local_irq_restore(flags);
+ return uncharged;
+}
+
/**
* mem_cgroup_uncharge - uncharge a page
* @page: page to uncharge
@@ -6563,11 +6600,10 @@ void mem_cgroup_cancel_charge(struct pag
*/
void mem_cgroup_uncharge(struct page *page)
{
- struct memcg_batch_info *batch;
unsigned int nr_pages = 1;
struct mem_cgroup *memcg;
struct page_cgroup *pc;
- unsigned long flags;
+ unsigned long pc_flags;
VM_BUG_ON_PAGE(PageLRU(page), page);
VM_BUG_ON_PAGE(page_count(page), page);
@@ -6591,35 +6627,20 @@ void mem_cgroup_uncharge(struct page *pa
* exclusive access to the page.
*/
memcg = pc->mem_cgroup;
- flags = pc->flags;
+ pc_flags = pc->flags;
pc->flags = 0;
mem_cgroup_charge_statistics(memcg, page, -nr_pages);
memcg_check_events(memcg, page);
- batch = ¤t->memcg_batch;
- if (!batch->memcg)
- batch->memcg = memcg;
- else if (batch->memcg != memcg)
- goto uncharge;
- if (nr_pages > 1)
- goto uncharge;
- if (!batch->do_batch)
- goto uncharge;
- if (test_thread_flag(TIF_MEMDIE))
- goto uncharge;
- if (flags & PCG_MEM)
- batch->nr_pages++;
- if (flags & PCG_MEMSW)
- batch->memsw_nr_pages++;
- return;
-uncharge:
- if (flags & PCG_MEM)
+ if (uncharge_batched(memcg, pc_flags, nr_pages))
+ return;
+
+ if (pc_flags & PCG_MEM)
res_counter_uncharge(&memcg->res, nr_pages * PAGE_SIZE);
- if (flags & PCG_MEMSW)
+ if (pc_flags & PCG_MEMSW)
res_counter_uncharge(&memcg->memsw, nr_pages * PAGE_SIZE);
- if (batch->memcg != memcg)
- memcg_oom_recover(memcg);
+ memcg_oom_recover(memcg);
}
/**
_
Patches currently in -mm which might be from hannes@xxxxxxxxxxx are
memcg-cleanup-memcg_cache_params-refcnt-usage.patch
memcg-destroy-kmem-caches-when-last-slab-is-freed.patch
memcg-mark-caches-that-belong-to-offline-memcgs-as-dead.patch
slub-dont-fail-kmem_cache_shrink-if-slab-placement-optimization-fails.patch
slub-make-slab_free-non-preemptable.patch
memcg-wait-for-kfrees-to-finish-before-destroying-cache.patch
slub-make-dead-memcg-caches-discard-free-slabs-immediately.patch
slub-kmem_cache_shrink-check-if-partial-list-is-empty-under-list_lock.patch
slab-do-not-keep-free-objects-slabs-on-dead-memcg-caches.patch
slab-set-free_limit-for-dead-caches-to-0.patch
vmalloc-use-rcu-list-iterator-to-reduce-vmap_area_lock-contention.patch
mm-page-flags-clean-up-the-page-flag-test-set-clear-macros.patch
mm-memcontrol-fold-mem_cgroup_do_charge.patch
mm-memcontrol-rearrange-charging-fast-path.patch
mm-memcontrol-reclaim-at-least-once-for-__gfp_noretry.patch
mm-huge_memory-use-gfp_transhuge-when-charging-huge-pages.patch
mm-memcontrol-retry-reclaim-for-oom-disabled-and-__gfp_nofail-charges.patch
mm-memcontrol-remove-explicit-oom-parameter-in-charge-path.patch
mm-memcontrol-simplify-move-precharge-function.patch
mm-memcontrol-catch-root-bypass-in-move-precharge.patch
mm-memcontrol-use-root_mem_cgroup-res_counter.patch
mm-memcontrol-remove-ordering-between-pc-mem_cgroup-and-pagecgroupused.patch
mm-memcontrol-do-not-acquire-page_cgroup-lock-for-kmem-pages.patch
mm-memcontrol-rewrite-charge-api.patch
mm-memcontrol-rewrite-charge-api-fix-3.patch
mm-memcontrol-rewrite-uncharge-api.patch
mm-memcontrol-rewrite-uncharge-api-fix-2.patch
mm-memcontrol-rewrite-uncharge-api-fix-4.patch
mm-memcontrol-rewrite-uncharge-api-fix-5.patch
mm-memcontrol-rewrite-charge-api-fix-shmem_unuse.patch
page-cgroup-trivial-cleanup.patch
page-cgroup-get-rid-of-nr_pcg_flags.patch
memcg-remove-lookup_cgroup_page-prototype.patch
mm-vmscan-remove-remains-of-kswapd-managed-zone-all_unreclaimable.patch
mm-vmscan-rework-compaction-ready-signaling-in-direct-reclaim.patch
mm-vmscan-remove-all_unreclaimable.patch
mm-vmscan-move-swappiness-out-of-scan_control.patch
mm-export-nr_shmem-via-sysinfo2-si_meminfo-interfaces.patch
mm-replace-init_page_accessed-by-__setpagereferenced.patch
mm-zbud-zbud_alloc-minor-param-change.patch
mm-zbud-change-zbud_alloc-size-type-to-size_t.patch
mm-zpool-implement-common-zpool-api-to-zbud-zsmalloc.patch
mm-zpool-zbud-zsmalloc-implement-zpool.patch
mm-zpool-update-zswap-to-use-zpool.patch
mm-zpool-prevent-zbud-zsmalloc-from-unloading-when-used.patch
nilfs2-integrate-sysfs-support-into-driver-fix.patch
memcg-deprecate-memoryforce_empty-knob.patch
memcg-deprecate-memoryforce_empty-knob-fix.patch
debugging-keep-track-of-page-owners.patch
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