diff options
author | Johannes Weiner <hannes@cmpxchg.org> | 2014-10-29 21:50:51 (GMT) |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-10-29 23:33:15 (GMT) |
commit | 8186eb6a799e4e32f984b55858d8e393938be0c1 (patch) | |
tree | 972a445b8a00c5c0f0a360d30893239cfa1f4e8e | |
parent | d7365e783edb858279be1d03f61bc8d5d3383d90 (diff) | |
download | linux-8186eb6a799e4e32f984b55858d8e393938be0c1.tar.xz |
mm: rmap: split out page_remove_file_rmap()
page_remove_rmap() has too many branches on PageAnon() and is hard to
follow. Move the file part into a separate function.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Cc: Vladimir Davydov <vdavydov@parallels.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r-- | mm/rmap.c | 78 |
1 files changed, 46 insertions, 32 deletions
@@ -1054,6 +1054,36 @@ void page_add_file_rmap(struct page *page) mem_cgroup_end_page_stat(memcg, locked, flags); } +static void page_remove_file_rmap(struct page *page) +{ + struct mem_cgroup *memcg; + unsigned long flags; + bool locked; + + memcg = mem_cgroup_begin_page_stat(page, &locked, &flags); + + /* page still mapped by someone else? */ + if (!atomic_add_negative(-1, &page->_mapcount)) + goto out; + + /* Hugepages are not counted in NR_FILE_MAPPED for now. */ + if (unlikely(PageHuge(page))) + 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_zone_page_state(page, NR_FILE_MAPPED); + mem_cgroup_dec_page_stat(memcg, MEM_CGROUP_STAT_FILE_MAPPED); + + if (unlikely(PageMlocked(page))) + clear_page_mlock(page); +out: + mem_cgroup_end_page_stat(memcg, locked, flags); +} + /** * page_remove_rmap - take down pte mapping from a page * @page: page to remove mapping from @@ -1062,46 +1092,33 @@ void page_add_file_rmap(struct page *page) */ void page_remove_rmap(struct page *page) { - struct mem_cgroup *uninitialized_var(memcg); - bool anon = PageAnon(page); - unsigned long flags; - bool locked; - - /* - * The anon case has no mem_cgroup page_stat to update; but may - * uncharge_page() below, where the lock ordering can deadlock if - * we hold the lock against page_stat move: so avoid it on anon. - */ - if (!anon) - memcg = mem_cgroup_begin_page_stat(page, &locked, &flags); + if (!PageAnon(page)) { + page_remove_file_rmap(page); + return; + } /* page still mapped by someone else? */ if (!atomic_add_negative(-1, &page->_mapcount)) - goto out; + return; + + /* Hugepages are not counted in NR_ANON_PAGES for now. */ + if (unlikely(PageHuge(page))) + return; /* - * Hugepages are not counted in NR_ANON_PAGES nor NR_FILE_MAPPED - * and not charged by memcg for now. - * * We use the irq-unsafe __{inc|mod}_zone_page_stat because * these counters are not modified in interrupt context, and - * these counters are not modified in interrupt context, and * pte lock(a spinlock) is held, which implies preemption disabled. */ - if (unlikely(PageHuge(page))) - goto out; - if (anon) { - if (PageTransHuge(page)) - __dec_zone_page_state(page, - NR_ANON_TRANSPARENT_HUGEPAGES); - __mod_zone_page_state(page_zone(page), NR_ANON_PAGES, - -hpage_nr_pages(page)); - } else { - __dec_zone_page_state(page, NR_FILE_MAPPED); - mem_cgroup_dec_page_stat(memcg, MEM_CGROUP_STAT_FILE_MAPPED); - } + if (PageTransHuge(page)) + __dec_zone_page_state(page, NR_ANON_TRANSPARENT_HUGEPAGES); + + __mod_zone_page_state(page_zone(page), NR_ANON_PAGES, + -hpage_nr_pages(page)); + if (unlikely(PageMlocked(page))) clear_page_mlock(page); + /* * It would be tidy to reset the PageAnon mapping here, * but that might overwrite a racing page_add_anon_rmap @@ -1111,9 +1128,6 @@ void page_remove_rmap(struct page *page) * Leaving it set also helps swapoff to reinstate ptes * faster for those pages still in swapcache. */ -out: - if (!anon) - mem_cgroup_end_page_stat(memcg, locked, flags); } /* |