Commit ac589cc5 authored by Xin Hao's avatar Xin Hao Committed by Peng Zhang
Browse files

mm: memcg: add THP swap out info for anonymous reclaim 

mainline inclusion
from mainline-v6.7-rc1
commit 811244a501b967b00fecb1ae906d5dc6329c91e0
category: other
bugzilla: https://gitee.com/openeuler/kernel/issues/I8YBMI

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=811244a501b967b00fecb1ae906d5dc6329c91e0

--------------------------------

At present, we support per-memcg reclaim strategy, however we do not know
the number of transparent huge pages being reclaimed, as we know the
transparent huge pages need to be splited before reclaim them, and they
will bring some performance bottleneck effect.  for example, when two
memcg (A & B) are doing reclaim for anonymous pages at same time, and 'A'
memcg is reclaiming a large number of transparent huge pages, we can
better analyze that the performance bottleneck will be caused by 'A'
memcg.  therefore, in order to better analyze such problems, there add THP
swap out info for per-memcg.

[akpm@linux-foundation.orgL fix swap_writepage_fs(), per Johannes]
  Link: https://lkml.kernel.org/r/20230913213343.GB48476@cmpxchg.org
Link: https://lkml.kernel.org/r/20230913164938.16918-1-vernhao@tencent.com


Signed-off-by: default avatarXin Hao <vernhao@tencent.com>
Suggested-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
Acked-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarZhangPeng <zhangpeng362@huawei.com>
parent a662a03b

Documentation/admin-guide/cgroup-v2.rst

+9 −0
Original line number Diff line number Diff line
@@ -1534,6 +1534,15 @@ PAGE_SIZE multiple when read back. 
		collapsing an existing range of pages. This counter is not

		present when CONFIG_TRANSPARENT_HUGEPAGE is not set.



	  thp_swpout (npn)

		Number of transparent hugepages which are swapout in one piece

		without splitting.



	  thp_swpout_fallback (npn)

		Number of transparent hugepages which were split before swapout.

		Usually because failed to allocate some continuous swap space

		for the huge page.



  memory.numa_stat

	A read-only nested-keyed file which exists on non-root cgroups.

mm/memcontrol.c

+2 −0
Original line number Diff line number Diff line
@@ -731,6 +731,8 @@ static const unsigned int memcg_vm_event_stat[] = { 
#ifdef CONFIG_TRANSPARENT_HUGEPAGE

	THP_FAULT_ALLOC,

	THP_COLLAPSE_ALLOC,

	THP_SWPOUT,

	THP_SWPOUT_FALLBACK,

#endif

};

mm/page_io.c

+4 −4
Original line number Diff line number Diff line
@@ -208,8 +208,10 @@ int swap_writepage(struct page *page, struct writeback_control *wbc) 
static inline void count_swpout_vm_event(struct folio *folio)

{

#ifdef CONFIG_TRANSPARENT_HUGEPAGE

	if (unlikely(folio_test_pmd_mappable(folio)))

	if (unlikely(folio_test_pmd_mappable(folio))) {

		count_memcg_folio_events(folio, THP_SWPOUT, 1);

		count_vm_event(THP_SWPOUT);

	}

#endif

	count_vm_events(PSWPOUT, folio_nr_pages(folio));

}
@@ -278,9 +280,6 @@ static void sio_write_complete(struct kiocb *iocb, long ret) 
			set_page_dirty(page);

			ClearPageReclaim(page);

		}

	} else {

		for (p = 0; p < sio->pages; p++)

			count_swpout_vm_event(page_folio(sio->bvec[p].bv_page));

	}



	for (p = 0; p < sio->pages; p++)
@@ -296,6 +295,7 @@ static void swap_writepage_fs(struct page *page, struct writeback_control *wbc) 
	struct file *swap_file = sis->swap_file;

	loff_t pos = page_file_offset(page);



	count_swpout_vm_event(page_folio(page));

	set_page_writeback(page);

	unlock_page(page);

	if (wbc->swap_plug)

mm/vmscan.c

+1 −0
Original line number Diff line number Diff line
@@ -1919,6 +1919,7 @@ static unsigned int shrink_folio_list(struct list_head *folio_list, 
								folio_list))

						goto activate_locked;

#ifdef CONFIG_TRANSPARENT_HUGEPAGE

					count_memcg_folio_events(folio, THP_SWPOUT_FALLBACK, 1);

					count_vm_event(THP_SWPOUT_FALLBACK);

#endif

					if (!add_to_swap(folio))