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mm: memcontrol: expose THP events on a per-memcg basis

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Currently THP allocation events data is fairly opaque, since you can
only get it system-wide.  This patch makes it easier to reason about
transparent hugepage behaviour on a per-memcg basis.

For anonymous THP-backed pages, we already have MEMCG_RSS_HUGE in v1,
which is used for v1's rss_huge [sic].  This is reused here as it's
fairly involved to untangle NR_ANON_THPS right now to make it per-memcg,
since right now some of this is delegated to rmap before we have any
memcg actually assigned to the page.  It's a good idea to rework that,
but let's leave untangling THP allocation for a future patch.

[akpm@linux-foundation.org: fix build]
[chris@chrisdown.name: fix memcontrol build when THP is disabled]
  Link: http://lkml.kernel.org/r/20190131160802.GA5777@chrisdown.name
Link: http://lkml.kernel.org/r/20190129205852.GA7310@chrisdown.name
Signed-off-by: Chris Down <chris@chrisdown.name>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Chris Down 2019-03-05 15:48:09 -08:00 committed by Linus Torvalds
parent 2bb0f34fe3
commit 1ff9e6e179
4 changed files with 36 additions and 0 deletions
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16
Documentation/admin-guide/cgroup-v2.rst
View File

@ -1189,6 +1189,10 @@ PAGE_SIZE multiple when read back.
Amount of cached filesystem data that was modified and
is currently being written back to disk
anon_thp
Amount of memory used in anonymous mappings backed by
transparent hugepages
inactive_anon, active_anon, inactive_file, active_file, unevictable
Amount of memory, swap-backed and filesystem-backed,
on the internal memory management lists used by the
@ -1248,6 +1252,18 @@ PAGE_SIZE multiple when read back.
Amount of reclaimed lazyfree pages
thp_fault_alloc
Number of transparent hugepages which were allocated to satisfy
a page fault, including COW faults. This counter is not present
when CONFIG_TRANSPARENT_HUGEPAGE is not set.
thp_collapse_alloc
Number of transparent hugepages which were allocated to allow
collapsing an existing range of pages. This counter is not
present when CONFIG_TRANSPARENT_HUGEPAGE is not set.
memory.swap.current
A read-only single value file which exists on non-root
cgroups.

2
mm/huge_memory.c
View File

@ -617,6 +617,7 @@ static vm_fault_t __do_huge_pmd_anonymous_page(struct vm_fault *vmf,
mm_inc_nr_ptes(vma->vm_mm);
spin_unlock(vmf->ptl);
count_vm_event(THP_FAULT_ALLOC);
count_memcg_events(memcg, THP_FAULT_ALLOC, 1);
}
return 0;
@ -1338,6 +1339,7 @@ alloc:
}
count_vm_event(THP_FAULT_ALLOC);
count_memcg_events(memcg, THP_FAULT_ALLOC, 1);
if (!page)
clear_huge_page(new_page, vmf->address, HPAGE_PMD_NR);

2
mm/khugepaged.c
View File

@ -1074,6 +1074,7 @@ static void collapse_huge_page(struct mm_struct *mm,
BUG_ON(!pmd_none(*pmd));
page_add_new_anon_rmap(new_page, vma, address, true);
mem_cgroup_commit_charge(new_page, memcg, false, true);
count_memcg_events(memcg, THP_COLLAPSE_ALLOC, 1);
lru_cache_add_active_or_unevictable(new_page, vma);
pgtable_trans_huge_deposit(mm, pmd, pgtable);
set_pmd_at(mm, address, pmd, _pmd);
@ -1502,6 +1503,7 @@ xa_unlocked:
page_ref_add(new_page, HPAGE_PMD_NR - 1);
set_page_dirty(new_page);
mem_cgroup_commit_charge(new_page, memcg, false, true);
count_memcg_events(memcg, THP_COLLAPSE_ALLOC, 1);
lru_cache_add_anon(new_page);
/*

16
mm/memcontrol.c
View File

@ -39,6 +39,7 @@
#include <linux/shmem_fs.h>
#include <linux/hugetlb.h>
#include <linux/pagemap.h>
#include <linux/vm_event_item.h>
#include <linux/smp.h>
#include <linux/page-flags.h>
#include <linux/backing-dev.h>
@ -5571,6 +5572,15 @@ static int memory_stat_show(struct seq_file *m, void *v)
seq_printf(m, "file_writeback %llu\n",
(u64)acc.stat[NR_WRITEBACK] * PAGE_SIZE);
/*
* TODO: We should eventually replace our own MEMCG_RSS_HUGE counter
* with the NR_ANON_THP vm counter, but right now it's a pain in the
* arse because it requires migrating the work out of rmap to a place
* where the page->mem_cgroup is set up and stable.
*/
seq_printf(m, "anon_thp %llu\n",
(u64)acc.stat[MEMCG_RSS_HUGE] * PAGE_SIZE);
for (i = 0; i < NR_LRU_LISTS; i++)
seq_printf(m, "%s %llu\n", mem_cgroup_lru_names[i],
(u64)acc.lru_pages[i] * PAGE_SIZE);
@ -5602,6 +5612,12 @@ static int memory_stat_show(struct seq_file *m, void *v)
seq_printf(m, "pglazyfree %lu\n", acc.events[PGLAZYFREE]);
seq_printf(m, "pglazyfreed %lu\n", acc.events[PGLAZYFREED]);
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
seq_printf(m, "thp_fault_alloc %lu\n", acc.events[THP_FAULT_ALLOC]);
seq_printf(m, "thp_collapse_alloc %lu\n",
acc.events[THP_COLLAPSE_ALLOC]);
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
return 0;
}