diff options
| author | Hugh Dickins <hugh@veritas.com> | 2008-03-04 14:29:07 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2008-03-04 16:35:15 -0800 |
| commit | 9442ec9df40d952b0de185ae5638a74970388e01 (patch) | |
| tree | 14b06d71203be119d93736464ca49f37ce402c1c /mm/page_alloc.c | |
| parent | 98837c7f82ef78aa38f40462aa2fcac68fd3acbf (diff) | |
| download | op-kernel-dev-9442ec9df40d952b0de185ae5638a74970388e01.zip op-kernel-dev-9442ec9df40d952b0de185ae5638a74970388e01.tar.gz | |
memcg: bad page if page_cgroup when free
Replace free_hot_cold_page's VM_BUG_ON(page_get_page_cgroup(page)) by a "Bad
page state" and clear: most users don't have CONFIG_DEBUG_VM on, and if it
were set here, it'd likely cause corruption when the page is reused.
Don't use page_assign_page_cgroup to clear it: that should be private to
memcontrol.c, and always called with the lock taken; and memmap_init_zone
doesn't need it either - like page->mapping and other pointers throughout the
kernel, Linux assumes pointers in zeroed structures are NULL pointers.
Instead use page_reset_bad_cgroup, added to memcontrol.h for this only.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: David Rientjes <rientjes@google.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hirokazu Takahashi <taka@valinux.co.jp>
Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/page_alloc.c')
| -rw-r--r-- | mm/page_alloc.c | 18 |
1 files changed, 12 insertions, 6 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index e76cf94..402a504 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -222,13 +222,19 @@ static inline int bad_range(struct zone *zone, struct page *page) static void bad_page(struct page *page) { - printk(KERN_EMERG "Bad page state in process '%s'\n" - KERN_EMERG "page:%p flags:0x%0*lx mapping:%p mapcount:%d count:%d\n" - KERN_EMERG "Trying to fix it up, but a reboot is needed\n" - KERN_EMERG "Backtrace:\n", + void *pc = page_get_page_cgroup(page); + + printk(KERN_EMERG "Bad page state in process '%s'\n" KERN_EMERG + "page:%p flags:0x%0*lx mapping:%p mapcount:%d count:%d\n", current->comm, page, (int)(2*sizeof(unsigned long)), (unsigned long)page->flags, page->mapping, page_mapcount(page), page_count(page)); + if (pc) { + printk(KERN_EMERG "cgroup:%p\n", pc); + page_reset_bad_cgroup(page); + } + printk(KERN_EMERG "Trying to fix it up, but a reboot is needed\n" + KERN_EMERG "Backtrace:\n"); dump_stack(); page->flags &= ~(1 << PG_lru | 1 << PG_private | @@ -454,6 +460,7 @@ static inline int free_pages_check(struct page *page) { if (unlikely(page_mapcount(page) | (page->mapping != NULL) | + (page_get_page_cgroup(page) != NULL) | (page_count(page) != 0) | (page->flags & ( 1 << PG_lru | @@ -603,6 +610,7 @@ static int prep_new_page(struct page *page, int order, gfp_t gfp_flags) { if (unlikely(page_mapcount(page) | (page->mapping != NULL) | + (page_get_page_cgroup(page) != NULL) | (page_count(page) != 0) | (page->flags & ( 1 << PG_lru | @@ -989,7 +997,6 @@ static void free_hot_cold_page(struct page *page, int cold) if (!PageHighMem(page)) debug_check_no_locks_freed(page_address(page), PAGE_SIZE); - VM_BUG_ON(page_get_page_cgroup(page)); arch_free_page(page, 0); kernel_map_pages(page, 1, 0); @@ -2528,7 +2535,6 @@ void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone, set_page_links(page, zone, nid, pfn); init_page_count(page); reset_page_mapcount(page); - page_assign_page_cgroup(page, NULL); SetPageReserved(page); /* |
