diff options
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/memcontrol.c | 62 | ||||
| -rw-r--r-- | mm/rmap.c | 28 |
2 files changed, 66 insertions, 24 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 8afed2819b8f..df1e180f6c30 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1910,32 +1910,59 @@ bool mem_cgroup_handle_oom(struct mem_cgroup *memcg, gfp_t mask, int order) * If there is, we take a lock. */ +void __mem_cgroup_begin_update_page_stat(struct page *page, + bool *locked, unsigned long *flags) +{ + struct mem_cgroup *memcg; + struct page_cgroup *pc; + + pc = lookup_page_cgroup(page); +again: + memcg = pc->mem_cgroup; + if (unlikely(!memcg || !PageCgroupUsed(pc))) + return; + /* + * If this memory cgroup is not under account moving, we don't + * need to take move_lock_page_cgroup(). Because we already hold + * rcu_read_lock(), any calls to move_account will be delayed until + * rcu_read_unlock() if mem_cgroup_stealed() == true. + */ + if (!mem_cgroup_stealed(memcg)) + return; + + move_lock_mem_cgroup(memcg, flags); + if (memcg != pc->mem_cgroup || !PageCgroupUsed(pc)) { + move_unlock_mem_cgroup(memcg, flags); + goto again; + } + *locked = true; +} + +void __mem_cgroup_end_update_page_stat(struct page *page, unsigned long *flags) +{ + struct page_cgroup *pc = lookup_page_cgroup(page); + + /* + * It's guaranteed that pc->mem_cgroup never changes while + * lock is held because a routine modifies pc->mem_cgroup + * should take move_lock_page_cgroup(). + */ + move_unlock_mem_cgroup(pc->mem_cgroup, flags); +} + void mem_cgroup_update_page_stat(struct page *page, enum mem_cgroup_page_stat_item idx, int val) { struct mem_cgroup *memcg; struct page_cgroup *pc = lookup_page_cgroup(page); - bool need_unlock = false; unsigned long uninitialized_var(flags); if (mem_cgroup_disabled()) return; -again: - rcu_read_lock(); + memcg = pc->mem_cgroup; if (unlikely(!memcg || !PageCgroupUsed(pc))) - goto out; - /* pc->mem_cgroup is unstable ? */ - if (unlikely(mem_cgroup_stealed(memcg))) { - /* take a lock against to access pc->mem_cgroup */ - move_lock_mem_cgroup(memcg, &flags); - if (memcg != pc->mem_cgroup || !PageCgroupUsed(pc)) { - move_unlock_mem_cgroup(memcg, &flags); - rcu_read_unlock(); - goto again; - } - need_unlock = true; - } + return; switch (idx) { case MEMCG_NR_FILE_MAPPED: @@ -1950,11 +1977,6 @@ again: } this_cpu_add(memcg->stat->count[idx], val); - -out: - if (unlikely(need_unlock)) - move_unlock_mem_cgroup(memcg, &flags); - rcu_read_unlock(); } /* diff --git a/mm/rmap.c b/mm/rmap.c index ebeb95e9150a..5b5ad584ffb7 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1148,10 +1148,15 @@ void page_add_new_anon_rmap(struct page *page, */ void page_add_file_rmap(struct page *page) { + bool locked; + unsigned long flags; + + mem_cgroup_begin_update_page_stat(page, &locked, &flags); if (atomic_inc_and_test(&page->_mapcount)) { __inc_zone_page_state(page, NR_FILE_MAPPED); mem_cgroup_inc_page_stat(page, MEMCG_NR_FILE_MAPPED); } + mem_cgroup_end_update_page_stat(page, &locked, &flags); } /** @@ -1162,9 +1167,21 @@ void page_add_file_rmap(struct page *page) */ void page_remove_rmap(struct page *page) { + bool anon = PageAnon(page); + bool locked; + unsigned long flags; + + /* + * 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) + mem_cgroup_begin_update_page_stat(page, &locked, &flags); + /* page still mapped by someone else? */ if (!atomic_add_negative(-1, &page->_mapcount)) - return; + goto out; /* * Now that the last pte has gone, s390 must transfer dirty @@ -1173,7 +1190,7 @@ void page_remove_rmap(struct page *page) * not if it's in swapcache - there might be another pte slot * containing the swap entry, but page not yet written to swap. */ - if ((!PageAnon(page) || PageSwapCache(page)) && + if ((!anon || PageSwapCache(page)) && page_test_and_clear_dirty(page_to_pfn(page), 1)) set_page_dirty(page); /* @@ -1181,8 +1198,8 @@ void page_remove_rmap(struct page *page) * and not charged by memcg for now. */ if (unlikely(PageHuge(page))) - return; - if (PageAnon(page)) { + goto out; + if (anon) { mem_cgroup_uncharge_page(page); if (!PageTransHuge(page)) __dec_zone_page_state(page, NR_ANON_PAGES); @@ -1202,6 +1219,9 @@ 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_update_page_stat(page, &locked, &flags); } /* |