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author | Johannes Weiner <hannes@cmpxchg.org> | 2020-06-03 16:01:57 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-06-03 20:09:47 -0700 |
commit | be5d0a74c62d8da43f9526a5b08cdd18e2bbc37a (patch) | |
tree | 6eeb26db5ce3b90cc2e79462e60e2d8e6119d5b6 /mm/rmap.c | |
parent | 0d1c20722ab333ac0ac03ae2188922c1021d3abc (diff) | |
download | linux-stable-be5d0a74c62d8da43f9526a5b08cdd18e2bbc37a.tar.gz linux-stable-be5d0a74c62d8da43f9526a5b08cdd18e2bbc37a.tar.bz2 linux-stable-be5d0a74c62d8da43f9526a5b08cdd18e2bbc37a.zip |
mm: memcontrol: switch to native NR_ANON_MAPPED counter
Memcg maintains a private MEMCG_RSS counter. This divergence from the
generic VM accounting means unnecessary code overhead, and creates a
dependency for memcg that page->mapping is set up at the time of charging,
so that page types can be told apart.
Convert the generic accounting sites to mod_lruvec_page_state and friends
to maintain the per-cgroup vmstat counter of NR_ANON_MAPPED. We use
lock_page_memcg() to stabilize page->mem_cgroup during rmap changes, the
same way we do for NR_FILE_MAPPED.
With the previous patch removing MEMCG_CACHE and the private NR_SHMEM
counter, this patch finally eliminates the need to have page->mapping set
up at charge time. However, we need to have page->mem_cgroup set up by
the time rmap runs and does the accounting, so switch the commit and the
rmap callbacks around.
v2: fix temporary accounting bug by switching rmap<->commit (Joonsoo)
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Link: http://lkml.kernel.org/r/20200508183105.225460-11-hannes@cmpxchg.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/rmap.c')
-rw-r--r-- | mm/rmap.c | 47 |
1 files changed, 29 insertions, 18 deletions
diff --git a/mm/rmap.c b/mm/rmap.c index f79a206b271a..150513d31efa 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1114,6 +1114,11 @@ void do_page_add_anon_rmap(struct page *page, bool compound = flags & RMAP_COMPOUND; bool first; + if (unlikely(PageKsm(page))) + lock_page_memcg(page); + else + VM_BUG_ON_PAGE(!PageLocked(page), page); + if (compound) { atomic_t *mapcount; VM_BUG_ON_PAGE(!PageLocked(page), page); @@ -1134,12 +1139,13 @@ void do_page_add_anon_rmap(struct page *page, */ if (compound) __inc_node_page_state(page, NR_ANON_THPS); - __mod_node_page_state(page_pgdat(page), NR_ANON_MAPPED, nr); + __mod_lruvec_page_state(page, NR_ANON_MAPPED, nr); } - if (unlikely(PageKsm(page))) - return; - VM_BUG_ON_PAGE(!PageLocked(page), page); + if (unlikely(PageKsm(page))) { + unlock_page_memcg(page); + return; + } /* address might be in next vma when migration races vma_adjust */ if (first) @@ -1181,7 +1187,7 @@ void page_add_new_anon_rmap(struct page *page, /* increment count (starts at -1) */ atomic_set(&page->_mapcount, 0); } - __mod_node_page_state(page_pgdat(page), NR_ANON_MAPPED, nr); + __mod_lruvec_page_state(page, NR_ANON_MAPPED, nr); __page_set_anon_rmap(page, vma, address, 1); } @@ -1230,13 +1236,12 @@ static void page_remove_file_rmap(struct page *page, bool compound) int i, nr = 1; VM_BUG_ON_PAGE(compound && !PageHead(page), page); - lock_page_memcg(page); /* Hugepages are not counted in NR_FILE_MAPPED for now. */ if (unlikely(PageHuge(page))) { /* hugetlb pages are always mapped with pmds */ atomic_dec(compound_mapcount_ptr(page)); - goto out; + return; } /* page still mapped by someone else? */ @@ -1246,14 +1251,14 @@ static void page_remove_file_rmap(struct page *page, bool compound) nr++; } if (!atomic_add_negative(-1, compound_mapcount_ptr(page))) - goto out; + return; if (PageSwapBacked(page)) __dec_node_page_state(page, NR_SHMEM_PMDMAPPED); else __dec_node_page_state(page, NR_FILE_PMDMAPPED); } else { if (!atomic_add_negative(-1, &page->_mapcount)) - goto out; + return; } /* @@ -1265,8 +1270,6 @@ static void page_remove_file_rmap(struct page *page, bool compound) if (unlikely(PageMlocked(page))) clear_page_mlock(page); -out: - unlock_page_memcg(page); } static void page_remove_anon_compound_rmap(struct page *page) @@ -1310,7 +1313,7 @@ static void page_remove_anon_compound_rmap(struct page *page) clear_page_mlock(page); if (nr) - __mod_node_page_state(page_pgdat(page), NR_ANON_MAPPED, -nr); + __mod_lruvec_page_state(page, NR_ANON_MAPPED, -nr); } /** @@ -1322,22 +1325,28 @@ static void page_remove_anon_compound_rmap(struct page *page) */ void page_remove_rmap(struct page *page, bool compound) { - if (!PageAnon(page)) - return page_remove_file_rmap(page, compound); + lock_page_memcg(page); - if (compound) - return page_remove_anon_compound_rmap(page); + if (!PageAnon(page)) { + page_remove_file_rmap(page, compound); + goto out; + } + + if (compound) { + page_remove_anon_compound_rmap(page); + goto out; + } /* page still mapped by someone else? */ if (!atomic_add_negative(-1, &page->_mapcount)) - return; + goto out; /* * We use the irq-unsafe __{inc|mod}_zone_page_stat because * these counters are not modified in interrupt context, and * pte lock(a spinlock) is held, which implies preemption disabled. */ - __dec_node_page_state(page, NR_ANON_MAPPED); + __dec_lruvec_page_state(page, NR_ANON_MAPPED); if (unlikely(PageMlocked(page))) clear_page_mlock(page); @@ -1354,6 +1363,8 @@ void page_remove_rmap(struct page *page, bool compound) * Leaving it set also helps swapoff to reinstate ptes * faster for those pages still in swapcache. */ +out: + unlock_page_memcg(page); } /* |