linux/mm, branch v2.6.28

mm: Don't touch uninitialized variable in do_pages_stat_array()

2008-12-16T16:19:23Z

Commit 80bba1290ab5122c60cdb73332b26d288dc8aedd removed one necessary variable initialization. As a result following warning happened: CC mm/migrate.o mm/migrate.c: In function 'sys_move_pages': mm/migrate.c:1001: warning: 'err' may be used uninitialized in this function More unfortunately, if find_vma() failed, kernel read uninitialized memory. Signed-off-by: KOSAKI Motohiro CC: Brice Goglin Cc: Christoph Lameter Cc: KAMEZAWA Hiroyuki Cc: Nick Piggin Cc: Hugh Dickins Signed-off-by: Linus Torvalds

slob: do not pass the SLAB flags as GFP in kmem_cache_create()

2008-12-16T00:27:06Z

The kmem_cache_create() function in the slob allocator passes the SLAB flags as GFP flags to the slob_alloc() function. The patch changes this call to pass GFP_KERNEL as the other allocators seem to do. Signed-off-by: Catalin Marinas Acked-by: Matt Mackall Cc: Cyrill Gorcunov Cc: Christoph Lameter Cc: Pekka Enberg Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

KSYM_SYMBOL_LEN fixes

2008-12-10T16:01:54Z

Miles Lane tailing /sys files hit a BUG which Pekka Enberg has tracked to my 966c8c12dc9e77f931e2281ba25d2f0244b06949 sprint_symbol(): use less stack exposing a bug in slub's list_locations() - kallsyms_lookup() writes a 0 to namebuf[KSYM_NAME_LEN-1], but that was beyond the end of page provided. The 100 slop which list_locations() allows at end of page looks roughly enough for all the other stuff it might print after the symbol before it checks again: break out KSYM_SYMBOL_LEN earlier than before. Latencytop and ftrace and are using KSYM_NAME_LEN buffers where they need KSYM_SYMBOL_LEN buffers, and vmallocinfo a 2*KSYM_NAME_LEN buffer where it wants a KSYM_SYMBOL_LEN buffer: fix those before anyone copies them. [akpm@linux-foundation.org: ftrace.h needs module.h] Signed-off-by: Hugh Dickins Cc: Christoph Lameter Cc Miles Lane Acked-by: Pekka Enberg Acked-by: Steven Rostedt Acked-by: Frederic Weisbecker Cc: Rusty Russell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: no get_user/put_user while holding mmap_sem in do_pages_stat?

2008-12-10T16:01:53Z

Since commit 2f007e74bb85b9fc4eab28524052161703300f1a, do_pages_stat() gets the page address from user-space and puts the corresponding status back while holding the mmap_sem for read. There is no need to hold mmap_sem there while some page-faults may occur. This patch adds a temporary address and status buffer so as to only hold mmap_sem while working on these kernel buffers. This is implemented by extracting do_pages_stat_array() out of do_pages_stat(). Signed-off-by: Brice Goglin Cc: Christoph Lameter Cc: KAMEZAWA Hiroyuki Cc: Nick Piggin Cc: Hugh Dickins Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

page_cgroup should ignore empty nodes

2008-12-10T16:01:53Z

Fix a total bootup freeze on ia64. Signed-off-by: KAMEZAWA Hiroyuki Tested-by: Li Zefan Reported-by: Li Zefan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: remove UP version of lru_add_drain_all()

2008-12-10T16:01:53Z

Currently, lru_add_drain_all() has two version. (1) use schedule_on_each_cpu() (2) don't use schedule_on_each_cpu() Gerald Schaefer reported it doesn't work well on SMP (not NUMA) S390 machine. offline_pages() calls lru_add_drain_all() followed by drain_all_pages(). While drain_all_pages() works on each cpu, lru_add_drain_all() only runs on the current cpu for architectures w/o CONFIG_NUMA. This let us run into the BUG_ON(!PageBuddy(page)) in __offline_isolated_pages() during memory hotplug stress test on s390. The page in question was still on the pcp list, because of a race with lru_add_drain_all() and drain_all_pages() on different cpus. Actually, Almost machine has CONFIG_UNEVICTABLE_LRU=y. Then almost machine use (1) version lru_add_drain_all although the machine is UP. Then this ifdef is not valueable. simple removing is better. Signed-off-by: KOSAKI Motohiro Cc: Christoph Lameter Cc: Lee Schermerhorn Acked-by: Gerald Schaefer Cc: Dave Hansen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm/backing-dev.c: remove recently-added WARN_ON()

2008-12-10T16:01:52Z

On second thoughts, this is just going to disturb people while telling us things which we already knew. Cc: Peter Korsgaard Cc: Peter Zijlstra Cc: Kay Sievers Cc: David Woodhouse Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

vmscan: evict streaming IO first

2008-12-02T23:50:40Z

Count the insertion of new pages in the statistics used to drive the pageout scanning code. This should help the kernel quickly evict streaming file IO. We count on the fact that new file pages start on the inactive file LRU and new anonymous pages start on the active anon list. This means streaming file IO will increment the recent scanned file statistic, while leaving the recent rotated file statistic alone, driving pageout scanning to the file LRUs. Pageout activity does its own list manipulation. Signed-off-by: Rik van Riel Cc: KAMEZAWA Hiroyuki Cc: KOSAKI Motohiro Tested-by: Gene Heskett Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

bdi: register sysfs bdi device only once per queue

2008-12-02T23:50:40Z

Devices which share the same queue, like floppies and mtd devices, get registered multiple times in the bdi interface, but bdi accounts only the last registered device of the devices sharing one queue. On remove, all earlier registered devices leak, stay around in sysfs, and cause "duplicate filename" errors if the devices are re-created. This prevents the creation of multiple bdi interfaces per queue, and the bdi device will carry the dev_t name of the block device which is the first one registered, of the pool of devices using the same queue. [akpm@linux-foundation.org: add a WARN_ON so we know which drivers are misbehaving] Tested-by: Peter Korsgaard Acked-by: Peter Zijlstra Signed-off-by: Kay Sievers Cc: David Woodhouse Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

memcg: memory hotplug fix for notifier callback

2008-12-02T03:55:24Z

Fixes for memcg/memory hotplug. While memory hotplug allocate/free memmap, page_cgroup doesn't free page_cgroup at OFFLINE when page_cgroup is allocated via bootomem. (Because freeing bootmem requires special care.) Then, if page_cgroup is allocated by bootmem and memmap is freed/allocated by memory hotplug, page_cgroup->page == page is no longer true. But current MEM_ONLINE handler doesn't check it and update page_cgroup->page if it's not necessary to allocate page_cgroup. (This was not found because memmap is not freed if SPARSEMEM_VMEMMAP is y.) And I noticed that MEM_ONLINE can be called against "part of section". So, freeing page_cgroup at CANCEL_ONLINE will cause trouble. (freeing used page_cgroup) Don't rollback at CANCEL. One more, current memory hotplug notifier is stopped by slub because it sets NOTIFY_STOP_MASK to return vaule. So, page_cgroup's callback never be called. (low priority than slub now.) I think this slub's behavior is not intentional(BUG). and fixes it. Another way to be considered about page_cgroup allocation: - free page_cgroup at OFFLINE even if it's from bootmem and remove specieal handler. But it requires more changes. Addresses http://bugzilla.kernel.org/show_bug.cgi?id=12041 Signed-off-by: KAMEZAWA Hiruyoki Cc: Li Zefan Cc: Balbir Singh Cc: Pavel Emelyanov Tested-by: Badari Pulavarty Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds