From 5cfb80a73b5a52fb19d8b0611203e4dd58e8e9a2 Mon Sep 17 00:00:00 2001 From: Daisuke Nishimura Date: Tue, 23 Mar 2010 13:35:11 -0700 Subject: memcg: disable move charge in no mmu case In commit 02491447 ("memcg: move charges of anonymous swap"), I tried to disable move charge feature in no mmu case by enclosing all the related functions with "#ifdef CONFIG_MMU", but the commit places these ifdefs in wrong place. (it seems that it's mangled while handling some fixes...) This patch fixes it up. Signed-off-by: Daisuke Nishimura Cc: Balbir Singh Cc: KAMEZAWA Hiroyuki Cc: Daisuke Nishimura Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memcontrol.c | 44 ++++++++++++++++++++++---------------------- 1 file changed, 22 insertions(+), 22 deletions(-) (limited to 'mm/memcontrol.c') diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 7973b5221fb..00dda352144 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -3946,28 +3946,6 @@ one_by_one: } return ret; } -#else /* !CONFIG_MMU */ -static int mem_cgroup_can_attach(struct cgroup_subsys *ss, - struct cgroup *cgroup, - struct task_struct *p, - bool threadgroup) -{ - return 0; -} -static void mem_cgroup_cancel_attach(struct cgroup_subsys *ss, - struct cgroup *cgroup, - struct task_struct *p, - bool threadgroup) -{ -} -static void mem_cgroup_move_task(struct cgroup_subsys *ss, - struct cgroup *cont, - struct cgroup *old_cont, - struct task_struct *p, - bool threadgroup) -{ -} -#endif /** * is_target_pte_for_mc - check a pte whether it is valid for move charge @@ -4330,6 +4308,28 @@ static void mem_cgroup_move_task(struct cgroup_subsys *ss, } mem_cgroup_clear_mc(); } +#else /* !CONFIG_MMU */ +static int mem_cgroup_can_attach(struct cgroup_subsys *ss, + struct cgroup *cgroup, + struct task_struct *p, + bool threadgroup) +{ + return 0; +} +static void mem_cgroup_cancel_attach(struct cgroup_subsys *ss, + struct cgroup *cgroup, + struct task_struct *p, + bool threadgroup) +{ +} +static void mem_cgroup_move_task(struct cgroup_subsys *ss, + struct cgroup *cont, + struct cgroup *old_cont, + struct task_struct *p, + bool threadgroup) +{ +} +#endif struct cgroup_subsys mem_cgroup_subsys = { .name = "memory", -- cgit v1.2.3-70-g09d2 From e7bbcdf3747e3919c31cfa87853c69d178bce548 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Tue, 23 Mar 2010 13:35:12 -0700 Subject: memcontrol: fix potential null deref There was a potential null deref introduced in c62b1a3b31b5 ("memcg: use generic percpu instead of private implementation"). Signed-off-by: Dan Carpenter Acked-by: KAMEZAWA Hiroyuki Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memcontrol.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'mm/memcontrol.c') diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 00dda352144..9ed760dc744 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -3691,8 +3691,10 @@ static struct mem_cgroup *mem_cgroup_alloc(void) else mem = vmalloc(size); - if (mem) - memset(mem, 0, size); + if (!mem) + return NULL; + + memset(mem, 0, size); mem->stat = alloc_percpu(struct mem_cgroup_stat_cpu); if (!mem->stat) { if (size < PAGE_SIZE) -- cgit v1.2.3-70-g09d2 From 8725d5416213a145ccc9c236dbd26830ba409e00 Mon Sep 17 00:00:00 2001 From: KAMEZAWA Hiroyuki Date: Tue, 6 Apr 2010 14:35:05 -0700 Subject: memcg: fix race in file_mapped accounting Presently, memcg's FILE_MAPPED accounting has following race with move_account (happens at rmdir()). increment page->mapcount (rmap.c) mem_cgroup_update_file_mapped() move_account() lock_page_cgroup() check page_mapped() if page_mapped(page)>1 { FILE_MAPPED -1 from old memcg FILE_MAPPED +1 to old memcg } ..... overwrite pc->mem_cgroup unlock_page_cgroup() lock_page_cgroup() FILE_MAPPED + 1 to pc->mem_cgroup unlock_page_cgroup() Then, old memcg (-1 file mapped) new memcg (+2 file mapped) This happens because move_account see page_mapped() which is not guarded by lock_page_cgroup(). This patch adds FILE_MAPPED flag to page_cgroup and move account information based on it. Now, all checks are synchronous with lock_page_cgroup(). Signed-off-by: KAMEZAWA Hiroyuki Reviewed-by: Balbir Singh Reviewed-by: Daisuke Nishimura Cc: Andrea Righi Cc: Andrea Arcangeli Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/page_cgroup.h | 6 ++++++ mm/memcontrol.c | 18 +++++++++--------- 2 files changed, 15 insertions(+), 9 deletions(-) (limited to 'mm/memcontrol.c') diff --git a/include/linux/page_cgroup.h b/include/linux/page_cgroup.h index 30b08136fdf..aef22ae2af4 100644 --- a/include/linux/page_cgroup.h +++ b/include/linux/page_cgroup.h @@ -39,6 +39,7 @@ enum { PCG_CACHE, /* charged as cache */ PCG_USED, /* this object is in use. */ PCG_ACCT_LRU, /* page has been accounted for */ + PCG_FILE_MAPPED, /* page is accounted as "mapped" */ }; #define TESTPCGFLAG(uname, lname) \ @@ -73,6 +74,11 @@ CLEARPCGFLAG(AcctLRU, ACCT_LRU) TESTPCGFLAG(AcctLRU, ACCT_LRU) TESTCLEARPCGFLAG(AcctLRU, ACCT_LRU) + +SETPCGFLAG(FileMapped, FILE_MAPPED) +CLEARPCGFLAG(FileMapped, FILE_MAPPED) +TESTPCGFLAG(FileMapped, FILE_MAPPED) + static inline int page_cgroup_nid(struct page_cgroup *pc) { return page_to_nid(pc->page); diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 9ed760dc744..f4ede99c8b9 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1359,16 +1359,19 @@ void mem_cgroup_update_file_mapped(struct page *page, int val) lock_page_cgroup(pc); mem = pc->mem_cgroup; - if (!mem) - goto done; - - if (!PageCgroupUsed(pc)) + if (!mem || !PageCgroupUsed(pc)) goto done; /* * Preemption is already disabled. We can use __this_cpu_xxx */ - __this_cpu_add(mem->stat->count[MEM_CGROUP_STAT_FILE_MAPPED], val); + if (val > 0) { + __this_cpu_inc(mem->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]); + SetPageCgroupFileMapped(pc); + } else { + __this_cpu_dec(mem->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]); + ClearPageCgroupFileMapped(pc); + } done: unlock_page_cgroup(pc); @@ -1801,16 +1804,13 @@ static void __mem_cgroup_commit_charge(struct mem_cgroup *mem, static void __mem_cgroup_move_account(struct page_cgroup *pc, struct mem_cgroup *from, struct mem_cgroup *to, bool uncharge) { - struct page *page; - VM_BUG_ON(from == to); VM_BUG_ON(PageLRU(pc->page)); VM_BUG_ON(!PageCgroupLocked(pc)); VM_BUG_ON(!PageCgroupUsed(pc)); VM_BUG_ON(pc->mem_cgroup != from); - page = pc->page; - if (page_mapped(page) && !PageAnon(page)) { + if (PageCgroupFileMapped(pc)) { /* Update mapped_file data for mem_cgroup */ preempt_disable(); __this_cpu_dec(from->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]); -- cgit v1.2.3-70-g09d2