When modifying PG_Dirty on cached file pages, update the new
MEM_CGROUP_STAT_DIRTY counter. This is done in the same places where
global NR_FILE_DIRTY is managed. The new memcg stat is visible in the
per memcg memory.stat cgroupfs file. The most recent past attempt at
this was http://thread.gmane.org/gmane.linux.kernel.cgroups/8632
The new accounting supports future efforts to add per cgroup dirty
page throttling and writeback. It also helps an administrator break
down a container's memory usage and provides evidence to understand
memcg oom kills (the new dirty count is included in memcg oom kill
messages).
The ability to move page accounting between memcg
(memory.move_charge_at_immigrate) makes this accounting more
complicated than the global counter. The existing
mem_cgroup_{begin,end}_page_stat() lock is used to serialize move
accounting with stat updates.
Typical update operation:
memcg = mem_cgroup_begin_page_stat(page)
if (TestSetPageDirty()) {
[...]
mem_cgroup_update_page_stat(memcg)
}
mem_cgroup_end_page_stat(memcg)
Summary of mem_cgroup_end_page_stat() overhead:
- Without CONFIG_MEMCG it's a no-op
- With CONFIG_MEMCG and no inter memcg task movement, it's just
rcu_read_lock()
- With CONFIG_MEMCG and inter memcg task movement, it's
rcu_read_lock() + spin_lock_irqsave()
A memcg parameter is added to several routines because their callers
now grab mem_cgroup_begin_page_stat() which returns the memcg later
needed by for mem_cgroup_update_page_stat().
Because mem_cgroup_begin_page_stat() may disable interrupts, some
adjustments are needed:
- move __mark_inode_dirty() from __set_page_dirty() to its caller.
__mark_inode_dirty() locking does not want interrupts disabled.
- use spin_lock_irqsave(tree_lock) rather than spin_lock_irq() in
__delete_from_page_cache(), replace_page_cache_page(),
invalidate_complete_page2(), and __remove_mapping().
text data bss dec hex filename
8925147 1774832 1785856 12485835 be84cb vmlinux-!CONFIG_MEMCG-before
8925339 1774832 1785856 12486027 be858b vmlinux-!CONFIG_MEMCG-after
+192 text bytes
8965977 1784992 1785856 12536825 bf4bf9 vmlinux-CONFIG_MEMCG-before
8966750 1784992 1785856 12537598 bf4efe vmlinux-CONFIG_MEMCG-after
+773 text bytes
Performance tests run on
v4.0-rc1-36-g4f671fe2f952. Lower is better for
all metrics, they're all wall clock or cycle counts. The read and write
fault benchmarks just measure fault time, they do not include I/O time.
* CONFIG_MEMCG not set:
baseline patched
kbuild 1m25.030000(+-0.088% 3 samples) 1m25.426667(+-0.120% 3 samples)
dd write 100 MiB 0.
859211561 +-15.10% 0.
874162885 +-15.03%
dd write 200 MiB 1.
670653105 +-17.87% 1.
669384764 +-11.99%
dd write 1000 MiB 8.
434691190 +-14.15% 8.
474733215 +-14.77%
read fault cycles 254.0(+-0.000% 10 samples) 253.0(+-0.000% 10 samples)
write fault cycles 2021.2(+-3.070% 10 samples) 1984.5(+-1.036% 10 samples)
* CONFIG_MEMCG=y root_memcg:
baseline patched
kbuild 1m25.716667(+-0.105% 3 samples) 1m25.686667(+-0.153% 3 samples)
dd write 100 MiB 0.
855650830 +-14.90% 0.
887557919 +-14.90%
dd write 200 MiB 1.
688322953 +-12.72% 1.
667682724 +-13.33%
dd write 1000 MiB 8.
418601605 +-14.30% 8.
673532299 +-15.00%
read fault cycles 266.0(+-0.000% 10 samples) 266.0(+-0.000% 10 samples)
write fault cycles 2051.7(+-1.349% 10 samples) 2049.6(+-1.686% 10 samples)
* CONFIG_MEMCG=y non-root_memcg:
baseline patched
kbuild 1m26.120000(+-0.273% 3 samples) 1m25.763333(+-0.127% 3 samples)
dd write 100 MiB 0.
861723964 +-15.25% 0.
818129350 +-14.82%
dd write 200 MiB 1.
669887569 +-13.30% 1.
698645885 +-13.27%
dd write 1000 MiB 8.
383191730 +-14.65% 8.
351742280 +-14.52%
read fault cycles 265.7(+-0.172% 10 samples) 267.0(+-0.000% 10 samples)
write fault cycles 2070.6(+-1.512% 10 samples) 2084.4(+-2.148% 10 samples)
As expected anon page faults are not affected by this patch.
tj: Updated to apply on top of the recent cancel_dirty_page() changes.
Signed-off-by: Sha Zhengju <handai.szj@gmail.com>
Signed-off-by: Greg Thelen <gthelen@google.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
pgpgout - # of uncharging events to the memory cgroup. The uncharging
event happens each time a page is unaccounted from the cgroup.
swap - # of bytes of swap usage
+dirty - # of bytes that are waiting to get written back to the disk.
writeback - # of bytes of file/anon cache that are queued for syncing to
disk.
inactive_anon - # of bytes of anonymous and swap cache memory on inactive
*
* If warn is true, then emit a warning if the page is not uptodate and has
* not been truncated.
+ *
+ * The caller must hold mem_cgroup_begin_page_stat() lock.
*/
-static void __set_page_dirty(struct page *page,
- struct address_space *mapping, int warn)
+static void __set_page_dirty(struct page *page, struct address_space *mapping,
+ struct mem_cgroup *memcg, int warn)
{
unsigned long flags;
spin_lock_irqsave(&mapping->tree_lock, flags);
if (page->mapping) { /* Race with truncate? */
WARN_ON_ONCE(warn && !PageUptodate(page));
- account_page_dirtied(page, mapping);
+ account_page_dirtied(page, mapping, memcg);
radix_tree_tag_set(&mapping->page_tree,
page_index(page), PAGECACHE_TAG_DIRTY);
}
spin_unlock_irqrestore(&mapping->tree_lock, flags);
- __mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
}
/*
int __set_page_dirty_buffers(struct page *page)
{
int newly_dirty;
+ struct mem_cgroup *memcg;
struct address_space *mapping = page_mapping(page);
if (unlikely(!mapping))
bh = bh->b_this_page;
} while (bh != head);
}
+ /*
+ * Use mem_group_begin_page_stat() to keep PageDirty synchronized with
+ * per-memcg dirty page counters.
+ */
+ memcg = mem_cgroup_begin_page_stat(page);
newly_dirty = !TestSetPageDirty(page);
spin_unlock(&mapping->private_lock);
if (newly_dirty)
- __set_page_dirty(page, mapping, 1);
+ __set_page_dirty(page, mapping, memcg, 1);
+
+ mem_cgroup_end_page_stat(memcg);
+
+ if (newly_dirty)
+ __mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
+
return newly_dirty;
}
EXPORT_SYMBOL(__set_page_dirty_buffers);
if (!test_set_buffer_dirty(bh)) {
struct page *page = bh->b_page;
+ struct address_space *mapping = NULL;
+ struct mem_cgroup *memcg;
+
+ memcg = mem_cgroup_begin_page_stat(page);
if (!TestSetPageDirty(page)) {
- struct address_space *mapping = page_mapping(page);
+ mapping = page_mapping(page);
if (mapping)
- __set_page_dirty(page, mapping, 0);
+ __set_page_dirty(page, mapping, memcg, 0);
}
+ mem_cgroup_end_page_stat(memcg);
+ if (mapping)
+ __mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
}
}
EXPORT_SYMBOL(mark_buffer_dirty);
loff_t end_offset;
loff_t offset;
int newly_dirty;
+ struct mem_cgroup *memcg;
if (unlikely(!mapping))
return !TestSetPageDirty(page);
offset += 1 << inode->i_blkbits;
} while (bh != head);
}
+ /*
+ * Use mem_group_begin_page_stat() to keep PageDirty synchronized with
+ * per-memcg dirty page counters.
+ */
+ memcg = mem_cgroup_begin_page_stat(page);
newly_dirty = !TestSetPageDirty(page);
spin_unlock(&mapping->private_lock);
spin_lock_irqsave(&mapping->tree_lock, flags);
if (page->mapping) { /* Race with truncate? */
WARN_ON_ONCE(!PageUptodate(page));
- account_page_dirtied(page, mapping);
+ account_page_dirtied(page, mapping, memcg);
radix_tree_tag_set(&mapping->page_tree,
page_index(page), PAGECACHE_TAG_DIRTY);
}
spin_unlock_irqrestore(&mapping->tree_lock, flags);
- __mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
}
+ mem_cgroup_end_page_stat(memcg);
+ if (newly_dirty)
+ __mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
return newly_dirty;
}
MEM_CGROUP_STAT_RSS, /* # of pages charged as anon rss */
MEM_CGROUP_STAT_RSS_HUGE, /* # of pages charged as anon huge */
MEM_CGROUP_STAT_FILE_MAPPED, /* # of pages charged as file rss */
+ MEM_CGROUP_STAT_DIRTY, /* # of dirty pages in page cache */
MEM_CGROUP_STAT_WRITEBACK, /* # of pages under writeback */
MEM_CGROUP_STAT_SWAP, /* # of pages, swapped out */
MEM_CGROUP_STAT_NSTATS,
int __set_page_dirty_no_writeback(struct page *page);
int redirty_page_for_writepage(struct writeback_control *wbc,
struct page *page);
-void account_page_dirtied(struct page *page, struct address_space *mapping);
-void account_page_cleaned(struct page *page, struct address_space *mapping);
+void account_page_dirtied(struct page *page, struct address_space *mapping,
+ struct mem_cgroup *memcg);
+void account_page_cleaned(struct page *page, struct address_space *mapping,
+ struct mem_cgroup *memcg);
int set_page_dirty(struct page *page);
int set_page_dirty_lock(struct page *page);
void cancel_dirty_page(struct page *page);
int add_to_page_cache_lru(struct page *page, struct address_space *mapping,
pgoff_t index, gfp_t gfp_mask);
extern void delete_from_page_cache(struct page *page);
-extern void __delete_from_page_cache(struct page *page, void *shadow);
+extern void __delete_from_page_cache(struct page *page, void *shadow,
+ struct mem_cgroup *memcg);
int replace_page_cache_page(struct page *old, struct page *new, gfp_t gfp_mask);
/*
* ->tree_lock (page_remove_rmap->set_page_dirty)
* bdi.wb->list_lock (page_remove_rmap->set_page_dirty)
* ->inode->i_lock (page_remove_rmap->set_page_dirty)
+ * ->memcg->move_lock (page_remove_rmap->mem_cgroup_begin_page_stat)
* bdi.wb->list_lock (zap_pte_range->set_page_dirty)
* ->inode->i_lock (zap_pte_range->set_page_dirty)
* ->private_lock (zap_pte_range->__set_page_dirty_buffers)
/*
* Delete a page from the page cache and free it. Caller has to make
* sure the page is locked and that nobody else uses it - or that usage
- * is safe. The caller must hold the mapping's tree_lock.
+ * is safe. The caller must hold the mapping's tree_lock and
+ * mem_cgroup_begin_page_stat().
*/
-void __delete_from_page_cache(struct page *page, void *shadow)
+void __delete_from_page_cache(struct page *page, void *shadow,
+ struct mem_cgroup *memcg)
{
struct address_space *mapping = page->mapping;
* anyway will be cleared before returning page into buddy allocator.
*/
if (WARN_ON_ONCE(PageDirty(page)))
- account_page_cleaned(page, mapping);
+ account_page_cleaned(page, mapping, memcg);
}
/**
void delete_from_page_cache(struct page *page)
{
struct address_space *mapping = page->mapping;
+ struct mem_cgroup *memcg;
+ unsigned long flags;
+
void (*freepage)(struct page *);
BUG_ON(!PageLocked(page));
freepage = mapping->a_ops->freepage;
- spin_lock_irq(&mapping->tree_lock);
- __delete_from_page_cache(page, NULL);
- spin_unlock_irq(&mapping->tree_lock);
+
+ memcg = mem_cgroup_begin_page_stat(page);
+ spin_lock_irqsave(&mapping->tree_lock, flags);
+ __delete_from_page_cache(page, NULL, memcg);
+ spin_unlock_irqrestore(&mapping->tree_lock, flags);
+ mem_cgroup_end_page_stat(memcg);
if (freepage)
freepage(page);
if (!error) {
struct address_space *mapping = old->mapping;
void (*freepage)(struct page *);
+ struct mem_cgroup *memcg;
+ unsigned long flags;
pgoff_t offset = old->index;
freepage = mapping->a_ops->freepage;
new->mapping = mapping;
new->index = offset;
- spin_lock_irq(&mapping->tree_lock);
- __delete_from_page_cache(old, NULL);
+ memcg = mem_cgroup_begin_page_stat(old);
+ spin_lock_irqsave(&mapping->tree_lock, flags);
+ __delete_from_page_cache(old, NULL, memcg);
error = radix_tree_insert(&mapping->page_tree, offset, new);
BUG_ON(error);
mapping->nrpages++;
__inc_zone_page_state(new, NR_FILE_PAGES);
if (PageSwapBacked(new))
__inc_zone_page_state(new, NR_SHMEM);
- spin_unlock_irq(&mapping->tree_lock);
+ spin_unlock_irqrestore(&mapping->tree_lock, flags);
+ mem_cgroup_end_page_stat(memcg);
mem_cgroup_migrate(old, new, true);
radix_tree_preload_end();
if (freepage)
"rss",
"rss_huge",
"mapped_file",
+ "dirty",
"writeback",
"swap",
};
return memcg;
}
+EXPORT_SYMBOL(mem_cgroup_begin_page_stat);
/**
* mem_cgroup_end_page_stat - finish a page state statistics transaction
rcu_read_unlock();
}
+EXPORT_SYMBOL(mem_cgroup_end_page_stat);
/**
* mem_cgroup_update_page_stat - update page state statistics
{
unsigned long flags;
int ret;
+ bool anon;
VM_BUG_ON(from == to);
VM_BUG_ON_PAGE(PageLRU(page), page);
if (page->mem_cgroup != from)
goto out_unlock;
+ anon = PageAnon(page);
+
spin_lock_irqsave(&from->move_lock, flags);
- if (!PageAnon(page) && page_mapped(page)) {
+ if (!anon && page_mapped(page)) {
__this_cpu_sub(from->stat->count[MEM_CGROUP_STAT_FILE_MAPPED],
nr_pages);
__this_cpu_add(to->stat->count[MEM_CGROUP_STAT_FILE_MAPPED],
nr_pages);
}
+ /*
+ * move_lock grabbed above and caller set from->moving_account, so
+ * mem_cgroup_update_page_stat() will serialize updates to PageDirty.
+ * So mapping should be stable for dirty pages.
+ */
+ if (!anon && PageDirty(page)) {
+ struct address_space *mapping = page_mapping(page);
+
+ if (mapping_cap_account_dirty(mapping)) {
+ __this_cpu_sub(from->stat->count[MEM_CGROUP_STAT_DIRTY],
+ nr_pages);
+ __this_cpu_add(to->stat->count[MEM_CGROUP_STAT_DIRTY],
+ nr_pages);
+ }
+ }
+
if (PageWriteback(page)) {
__this_cpu_sub(from->stat->count[MEM_CGROUP_STAT_WRITEBACK],
nr_pages);
/*
* Helper function for set_page_dirty family.
+ *
+ * Caller must hold mem_cgroup_begin_page_stat().
+ *
* NOTE: This relies on being atomic wrt interrupts.
*/
-void account_page_dirtied(struct page *page, struct address_space *mapping)
+void account_page_dirtied(struct page *page, struct address_space *mapping,
+ struct mem_cgroup *memcg)
{
trace_writeback_dirty_page(page, mapping);
if (mapping_cap_account_dirty(mapping)) {
struct backing_dev_info *bdi = inode_to_bdi(mapping->host);
+ mem_cgroup_inc_page_stat(memcg, MEM_CGROUP_STAT_DIRTY);
__inc_zone_page_state(page, NR_FILE_DIRTY);
__inc_zone_page_state(page, NR_DIRTIED);
__inc_bdi_stat(bdi, BDI_RECLAIMABLE);
/*
* Helper function for deaccounting dirty page without writeback.
+ *
+ * Caller must hold mem_cgroup_begin_page_stat().
*/
-void account_page_cleaned(struct page *page, struct address_space *mapping)
+void account_page_cleaned(struct page *page, struct address_space *mapping,
+ struct mem_cgroup *memcg)
{
if (mapping_cap_account_dirty(mapping)) {
+ mem_cgroup_dec_page_stat(memcg, MEM_CGROUP_STAT_DIRTY);
dec_zone_page_state(page, NR_FILE_DIRTY);
dec_bdi_stat(inode_to_bdi(mapping->host), BDI_RECLAIMABLE);
task_io_account_cancelled_write(PAGE_CACHE_SIZE);
*/
int __set_page_dirty_nobuffers(struct page *page)
{
+ struct mem_cgroup *memcg;
+
+ memcg = mem_cgroup_begin_page_stat(page);
if (!TestSetPageDirty(page)) {
struct address_space *mapping = page_mapping(page);
unsigned long flags;
- if (!mapping)
+ if (!mapping) {
+ mem_cgroup_end_page_stat(memcg);
return 1;
+ }
spin_lock_irqsave(&mapping->tree_lock, flags);
BUG_ON(page_mapping(page) != mapping);
WARN_ON_ONCE(!PagePrivate(page) && !PageUptodate(page));
- account_page_dirtied(page, mapping);
+ account_page_dirtied(page, mapping, memcg);
radix_tree_tag_set(&mapping->page_tree, page_index(page),
PAGECACHE_TAG_DIRTY);
spin_unlock_irqrestore(&mapping->tree_lock, flags);
+ mem_cgroup_end_page_stat(memcg);
+
if (mapping->host) {
/* !PageAnon && !swapper_space */
__mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
}
return 1;
}
+ mem_cgroup_end_page_stat(memcg);
return 0;
}
EXPORT_SYMBOL(__set_page_dirty_nobuffers);
*/
void cancel_dirty_page(struct page *page)
{
- if (TestClearPageDirty(page))
- account_page_cleaned(page, page_mapping(page));
+ struct address_space *mapping = page_mapping(page);
+
+ if (mapping_cap_account_dirty(mapping)) {
+ struct mem_cgroup *memcg;
+
+ memcg = mem_cgroup_begin_page_stat(page);
+
+ if (TestClearPageDirty(page))
+ account_page_cleaned(page, mapping, memcg);
+
+ mem_cgroup_end_page_stat(memcg);
+ } else {
+ ClearPageDirty(page);
+ }
}
EXPORT_SYMBOL(cancel_dirty_page);
int clear_page_dirty_for_io(struct page *page)
{
struct address_space *mapping = page_mapping(page);
+ struct mem_cgroup *memcg;
+ int ret = 0;
BUG_ON(!PageLocked(page));
* always locked coming in here, so we get the desired
* exclusion.
*/
+ memcg = mem_cgroup_begin_page_stat(page);
if (TestClearPageDirty(page)) {
+ mem_cgroup_dec_page_stat(memcg, MEM_CGROUP_STAT_DIRTY);
dec_zone_page_state(page, NR_FILE_DIRTY);
dec_bdi_stat(inode_to_bdi(mapping->host),
BDI_RECLAIMABLE);
- return 1;
+ ret = 1;
}
- return 0;
+ mem_cgroup_end_page_stat(memcg);
+ return ret;
}
return TestClearPageDirty(page);
}
* swap_lock (in swap_duplicate, swap_info_get)
* mmlist_lock (in mmput, drain_mmlist and others)
* mapping->private_lock (in __set_page_dirty_buffers)
+ * mem_cgroup_{begin,end}_page_stat (memcg->move_lock)
+ * mapping->tree_lock (widely used)
* inode->i_lock (in set_page_dirty's __mark_inode_dirty)
* bdi.wb->list_lock (in set_page_dirty's __mark_inode_dirty)
* sb_lock (within inode_lock in fs/fs-writeback.c)
static int
invalidate_complete_page2(struct address_space *mapping, struct page *page)
{
+ struct mem_cgroup *memcg;
+ unsigned long flags;
+
if (page->mapping != mapping)
return 0;
if (page_has_private(page) && !try_to_release_page(page, GFP_KERNEL))
return 0;
- spin_lock_irq(&mapping->tree_lock);
+ memcg = mem_cgroup_begin_page_stat(page);
+ spin_lock_irqsave(&mapping->tree_lock, flags);
if (PageDirty(page))
goto failed;
BUG_ON(page_has_private(page));
- __delete_from_page_cache(page, NULL);
- spin_unlock_irq(&mapping->tree_lock);
+ __delete_from_page_cache(page, NULL, memcg);
+ spin_unlock_irqrestore(&mapping->tree_lock, flags);
+ mem_cgroup_end_page_stat(memcg);
if (mapping->a_ops->freepage)
mapping->a_ops->freepage(page);
page_cache_release(page); /* pagecache ref */
return 1;
failed:
- spin_unlock_irq(&mapping->tree_lock);
+ spin_unlock_irqrestore(&mapping->tree_lock, flags);
+ mem_cgroup_end_page_stat(memcg);
return 0;
}
static int __remove_mapping(struct address_space *mapping, struct page *page,
bool reclaimed)
{
+ unsigned long flags;
+ struct mem_cgroup *memcg;
+
BUG_ON(!PageLocked(page));
BUG_ON(mapping != page_mapping(page));
- spin_lock_irq(&mapping->tree_lock);
+ memcg = mem_cgroup_begin_page_stat(page);
+ spin_lock_irqsave(&mapping->tree_lock, flags);
/*
* The non racy check for a busy page.
*
swp_entry_t swap = { .val = page_private(page) };
mem_cgroup_swapout(page, swap);
__delete_from_swap_cache(page);
- spin_unlock_irq(&mapping->tree_lock);
+ spin_unlock_irqrestore(&mapping->tree_lock, flags);
+ mem_cgroup_end_page_stat(memcg);
swapcache_free(swap);
} else {
void (*freepage)(struct page *);
if (reclaimed && page_is_file_cache(page) &&
!mapping_exiting(mapping))
shadow = workingset_eviction(mapping, page);
- __delete_from_page_cache(page, shadow);
- spin_unlock_irq(&mapping->tree_lock);
+ __delete_from_page_cache(page, shadow, memcg);
+ spin_unlock_irqrestore(&mapping->tree_lock, flags);
+ mem_cgroup_end_page_stat(memcg);
if (freepage != NULL)
freepage(page);
return 1;
cannot_free:
- spin_unlock_irq(&mapping->tree_lock);
+ spin_unlock_irqrestore(&mapping->tree_lock, flags);
+ mem_cgroup_end_page_stat(memcg);
return 0;
}
projects / karo-tx-linux.git / commitdiff