aboutsummaryrefslogtreecommitdiff
path: root/mm
AgeCommit message (Collapse)Author
2009-05-07NOMMU: Don't check vm_region::vm_start is page aligned in add_nommu_region()David Howells
Don't check vm_region::vm_start is page aligned in add_nommu_region() because the region may reflect some non-page-aligned mapped file, such as could be obtained from RomFS XIP. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Greg Ungerer <gerg@uclinux.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-05-06nommu: make the initial mmap allocation excess behaviour Kconfig configurableDavid Howells
NOMMU mmap() has an option controlled by a sysctl variable that determines whether the allocations made by do_mmap_private() should have the excess space trimmed off and returned to the allocator. Make the initial setting of this variable a Kconfig configuration option. The reason there can be excess space is that the allocator only allocates in power-of-2 size chunks, but mmap()'s can be made in sizes that aren't a power of 2. There are two alternatives: (1) Keep the excess as dead space. The dead space then remains unused for the lifetime of the mapping. Mappings of shared objects such as libc, ld.so or busybox's text segment may retain their dead space forever. (2) Return the excess to the allocator. This means that the dead space is limited to less than a page per mapping, but it means that for a transient process, there's more chance of fragmentation as the excess space may be reused fairly quickly. During the boot process, a lot of transient processes are created, and this can cause a lot of fragmentation as the pagecache and various slabs grow greatly during this time. By turning off the trimming of excess space during boot and disabling batching of frees, Coldfire can manage to boot. A better way of doing things might be to have /sbin/init turn this option off. By that point libc, ld.so and init - which are all long-duration processes - have all been loaded and trimmed. Reported-by: Lanttor Guo <lanttor.guo@freescale.com> Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Lanttor Guo <lanttor.guo@freescale.com> Cc: Greg Ungerer <gerg@snapgear.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-05-06nommu: clamp zone_batchsize() to 0 under NOMMU conditionsDavid Howells
Clamp zone_batchsize() to 0 under NOMMU conditions to stop free_hot_cold_page() from queueing and batching frees. The problem is that under NOMMU conditions it is really important to be able to allocate large contiguous chunks of memory, but when munmap() or exit_mmap() releases big stretches of memory, return of these to the buddy allocator can be deferred, and when it does finally happen, it can be in small chunks. Whilst the fragmentation this incurs isn't so much of a problem under MMU conditions as userspace VM is glued together from individual pages with the aid of the MMU, it is a real problem if there isn't an MMU. By clamping the page freeing queue size to 0, pages are returned to the allocator immediately, and the buddy detector is more likely to be able to glue them together into large chunks immediately, and fragmentation is less likely to occur. By disabling batching of frees, and by turning off the trimming of excess space during boot, Coldfire can manage to boot. Reported-by: Lanttor Guo <lanttor.guo@freescale.com> Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Lanttor Guo <lanttor.guo@freescale.com> Cc: Greg Ungerer <gerg@snapgear.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-05-06mm: use roundown_pow_of_two() in zone_batchsize()David Howells
Use roundown_pow_of_two(N) in zone_batchsize() rather than (1 << (fls(N)-1)) as they are equivalent, and with the former it is easier to see what is going on. Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Lanttor Guo <lanttor.guo@freescale.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-05-06alloc_vmap_area: fix memory leakRalph Wuerthner
If alloc_vmap_area() fails the allocated struct vmap_area has to be freed. Signed-off-by: Ralph Wuerthner <ralphw@linux.vnet.ibm.com> Reviewed-by: Christoph Lameter <cl@linux-foundation.org> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Cc: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-05-06oom: prevent livelock when oom_kill_allocating_task is setDavid Rientjes
When /proc/sys/vm/oom_kill_allocating_task is set for large systems that want to avoid the lengthy tasklist scan, it's possible to livelock if current is ineligible for oom kill. This normally happens when it is set to OOM_DISABLE, but is also possible if any threads are sharing the same ->mm with a different tgid. So change __out_of_memory() to fall back to the full task-list scan if it was unable to kill `current'. Cc: Nick Piggin <npiggin@suse.de> Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-05-05Ignore madvise(MADV_WILLNEED) for hugetlbfs-backed regionsMel Gorman
madvise(MADV_WILLNEED) forces page cache readahead on a range of memory backed by a file. The assumption is made that the page required is order-0 and "normal" page cache. On hugetlbfs, this assumption is not true and order-0 pages are allocated and inserted into the hugetlbfs page cache. This leaks hugetlbfs page reservations and can cause BUGs to trigger related to corrupted page tables. This patch causes MADV_WILLNEED to be ignored for hugetlbfs-backed regions. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-05-02vmscan: avoid multiplication overflow in shrink_zone()Andrew Morton
Local variable `scan' can overflow on zones which are larger than (2G * 4k) / 100 = 80GB. Making it 64-bit on 64-bit will fix that up. Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Lee Schermerhorn <lee.schermerhorn@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-05-02mm: fix Committed_AS underflow on large NR_CPUS environmentKOSAKI Motohiro
The Committed_AS field can underflow in certain situations: > # while true; do cat /proc/meminfo | grep _AS; sleep 1; done | uniq -c > 1 Committed_AS: 18446744073709323392 kB > 11 Committed_AS: 18446744073709455488 kB > 6 Committed_AS: 35136 kB > 5 Committed_AS: 18446744073709454400 kB > 7 Committed_AS: 35904 kB > 3 Committed_AS: 18446744073709453248 kB > 2 Committed_AS: 34752 kB > 9 Committed_AS: 18446744073709453248 kB > 8 Committed_AS: 34752 kB > 3 Committed_AS: 18446744073709320960 kB > 7 Committed_AS: 18446744073709454080 kB > 3 Committed_AS: 18446744073709320960 kB > 5 Committed_AS: 18446744073709454080 kB > 6 Committed_AS: 18446744073709320960 kB Because NR_CPUS can be greater than 1000 and meminfo_proc_show() does not check for underflow. But NR_CPUS proportional isn't good calculation. In general, possibility of lock contention is proportional to the number of online cpus, not theorical maximum cpus (NR_CPUS). The current kernel has generic percpu-counter stuff. using it is right way. it makes code simplify and percpu_counter_read_positive() don't make underflow issue. Reported-by: Dave Hansen <dave@linux.vnet.ibm.com> Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Eric B Munson <ebmunson@us.ibm.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: <stable@kernel.org> [All kernel versions] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-05-02memcg: fix mem_cgroup_shrink_usage()Daisuke Nishimura
Current mem_cgroup_shrink_usage() has two problems. 1. It doesn't call mem_cgroup_out_of_memory and doesn't update last_oom_jiffies, so pagefault_out_of_memory invokes global OOM. 2. Considering hierarchy, shrinking has to be done from the mem_over_limit, not from the memcg which the page would be charged to. mem_cgroup_try_charge_swapin() does all of these things properly, so we use it and call cancel_charge_swapin when it succeeded. The name of "shrink_usage" is not appropriate for this behavior, so we change it too. Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Li Zefan <lizf@cn.fujitsu.cn> Cc: Paul Menage <menage@google.com> Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-05-02mm: close page_mkwrite racesNick Piggin
Change page_mkwrite to allow implementations to return with the page locked, and also change it's callers (in page fault paths) to hold the lock until the page is marked dirty. This allows the filesystem to have full control of page dirtying events coming from the VM. Rather than simply hold the page locked over the page_mkwrite call, we call page_mkwrite with the page unlocked and allow callers to return with it locked, so filesystems can avoid LOR conditions with page lock. The problem with the current scheme is this: a filesystem that wants to associate some metadata with a page as long as the page is dirty, will perform this manipulation in its ->page_mkwrite. It currently then must return with the page unlocked and may not hold any other locks (according to existing page_mkwrite convention). In this window, the VM could write out the page, clearing page-dirty. The filesystem has no good way to detect that a dirty pte is about to be attached, so it will happily write out the page, at which point, the filesystem may manipulate the metadata to reflect that the page is no longer dirty. It is not always possible to perform the required metadata manipulation in ->set_page_dirty, because that function cannot block or fail. The filesystem may need to allocate some data structure, for example. And the VM cannot mark the pte dirty before page_mkwrite, because page_mkwrite is allowed to fail, so we must not allow any window where the page could be written to if page_mkwrite does fail. This solution of holding the page locked over the 3 critical operations (page_mkwrite, setting the pte dirty, and finally setting the page dirty) closes out races nicely, preventing page cleaning for writeout being initiated in that window. This provides the filesystem with a strong synchronisation against the VM here. - Sage needs this race closed for ceph filesystem. - Trond for NFS (http://bugzilla.kernel.org/show_bug.cgi?id=12913). - I need it for fsblock. - I suspect other filesystems may need it too (eg. btrfs). - I have converted buffer.c to the new locking. Even simple block allocation under dirty pages might be susceptible to i_size changing under partial page at the end of file (we also have a buffer.c-side problem here, but it cannot be fixed properly without this patch). - Other filesystems (eg. NFS, maybe btrfs) will need to change their page_mkwrite functions themselves. [ This also moves page_mkwrite another step closer to fault, which should eventually allow page_mkwrite to be moved into ->fault, and thus avoiding a filesystem calldown and page lock/unlock cycle in __do_fault. ] [akpm@linux-foundation.org: fix derefs of NULL ->mapping] Cc: Sage Weil <sage@newdream.net> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-05-02memcg: fix try_get_mem_cgroup_from_swapcache()Daisuke Nishimura
This is a bugfix for commit 3c776e64660028236313f0e54f3a9945764422df ("memcg: charge swapcache to proper memcg"). Used bit of swapcache is solid under page lock, but considering move_account, pc->mem_cgroup is not. We need lock_page_cgroup() anyway. Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-05-02mm: fix pageref leak in do_swap_page()Johannes Weiner
By the time the memory cgroup code is notified about a swapin we already hold a reference on the fault page. If the cgroup callback fails make sure to unlock AND release the page reference which was taken by lookup_swap_cach(), or we leak the reference. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-21vmscan,memcg: reintroduce sc->may_swapKOSAKI Motohiro
Commit a6dc60f8975ad96d162915e07703a4439c80dcf0 ("vmscan: rename sc.may_swap to may_unmap") removed the may_swap flag, but memcg had used it as a flag for "we need to use swap?", as the name indicate. And in the current implementation, memcg cannot reclaim mapped file caches when mem+swap hits the limit. re-introduce may_swap flag and handle it at get_scan_ratio(). This patch doesn't influence any scan_control users other than memcg. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-18PM/Hibernate: Fix memory shrinkingRafael J. Wysocki
Commit d979677c4c0 ("mm: shrink_all_memory(): use sc.nr_reclaimed") broke the memory shrinking used by hibernation, becuse it did not update shrink_all_zones() in accordance with the other changes it made. Fix this by making shrink_all_zones() update sc->nr_reclaimed instead of overwriting its value. This fixes http://bugzilla.kernel.org/show_bug.cgi?id=13058 Reported-and-tested-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-16mm: pass correct mm when growing stackHugh Dickins
Tetsuo Handa reports seeing the WARN_ON(current->mm == NULL) in security_vm_enough_memory(), when do_execve() is touching the target mm's stack, to set up its args and environment. Yes, a UMH_NO_WAIT or UMH_WAIT_PROC call_usermodehelper() spawns an mm-less kernel thread to do the exec. And in any case, that vm_enough_memory check when growing stack ought to be done on the target mm, not on the execer's mm (though apart from the warning, it only makes a slight tweak to OVERCOMMIT_NEVER behaviour). Reported-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Signed-off-by: Hugh Dickins <hugh@veritas.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-16Export filemap_write_and_wait_rangeChris Mason
This wasn't exported before and is useful (used by the experimental ext3 data=guarded code) Signed-off-by: Chris Mason <chris.mason@oracle.com> Acked-by: Theodore Tso <tytso@mit.edu> Acked-by: Jan Kara <jack@suse.cz> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-13shmem: respect MAX_LFS_FILESIZEHugh Dickins
SHMEM_MAX_BYTES was derived from the maximum size of its triple-indirect swap vector, forgetting to take the MAX_LFS_FILESIZE limit into account. Never mind 256kB pages, even 8kB pages on 32-bit kernels allowed files to grow slightly bigger than that supposed maximum. Fix this by using the min of both (at build time not run time). And it happens that this calculation is good as far as 8MB pages on 32-bit or 16MB pages on 64-bit: though SHMSWP_MAX_INDEX gets truncated before that, it's truncated to such large numbers that we don't need to care. [akpm@linux-foundation.org: it needs pagemap.h] [akpm@linux-foundation.org: fix sparc64 min() warnings] Signed-off-by: Hugh Dickins <hugh@veritas.com> Cc: Yuri Tikhonov <yur@emcraft.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-13shmem: fix division by zeroYuri Tikhonov
Fix a division by zero which we have in shmem_truncate_range() and shmem_unuse_inode() when using big PAGE_SIZE values (e.g. 256kB on ppc44x). With 256kB PAGE_SIZE, the ENTRIES_PER_PAGEPAGE constant becomes too large (0x1.0000.0000) on a 32-bit kernel, so this patch just changes its type from 'unsigned long' to 'unsigned long long'. Hugh: reverted its unsigned long longs in shmem_truncate_range() and shmem_getpage(): the pagecache index cannot be more than an unsigned long, so the divisions by zero occurred in unreached code. It's a pity we need any ULL arithmetic here, but I found no pretty way to avoid it. Signed-off-by: Yuri Tikhonov <yur@emcraft.com> Signed-off-by: Hugh Dickins <hugh@veritas.com> Cc: Paul Mackerras <paulus@samba.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-13memcg: remove warning when CONFIG_DEBUG_VM=nKAMEZAWA Hiroyuki
mm/memcontrol.c:318: warning: `mem_cgroup_is_obsolete' defined but not used [akpm@linux-foundation.org: simplify as suggested by Balbir] Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-13mm: document get_user_pages_fast()Andy Grover
While better than get_user_pages(), the usage of gupf(), especially the return values and the fact that it can potentially only partially pin the range, warranted some documentation. Signed-off-by: Andy Grover <andy.grover@oracle.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-13mm: point the UNEVICTABLE_LRU config option at the documentationDavid Howells
Point the UNEVICTABLE_LRU config option at the documentation describing the option. Signed-off-by: David Howells <dhowells@redhat.com> Cc: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Rik van Riel <riel@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-13filemap: fix kernel-doc warningsRandy Dunlap
Fix filemap.c kernel-doc warnings: Warning(mm/filemap.c:575): No description found for parameter 'page' Warning(mm/filemap.c:575): No description found for parameter 'waiter' Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-07mm: add /proc controls for pdflush threadsPeter W Morreale
Add /proc entries to give the admin the ability to control the minimum and maximum number of pdflush threads. This allows finer control of pdflush on both large and small machines. The rationale is simply one size does not fit all. Admins on large and/or small systems may want to tune the min/max pdflush thread count to best suit their needs. Right now the min/max is hardcoded to 2/8. While probably a fair estimate for smaller machines, large machines with large numbers of CPUs and large numbers of filesystems/block devices may benefit from larger numbers of threads working on different block devices. Even if the background flushing algorithm is radically changed, it is still likely that multiple threads will be involved and admins would still desire finer control on the min/max other than to have to recompile the kernel. The patch adds '/proc/sys/vm/nr_pdflush_threads_min' and '/proc/sys/vm/nr_pdflush_threads_max' with r/w permissions. The minimum value for nr_pdflush_threads_min is 1 and the maximum value is the current value of nr_pdflush_threads_max. This minimum is required since additional thread creation is performed in a pdflush thread itself. The minimum value for nr_pdflush_threads_max is the current value of nr_pdflush_threads_min and the maximum value can be 1000. Documentation/sysctl/vm.txt is also updated. [akpm@linux-foundation.org: fix comment, fix whitespace, use __read_mostly] Signed-off-by: Peter W Morreale <pmorreale@novell.com> Reviewed-by: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-07mm: fix pdflush thread creation upper boundPeter W Morreale
Fix a race on creating pdflush threads. Without the patch, it is possible to create more than MAX_PDFLUSH_THREADS threads, and this has been observed in practice on IO loaded SMP machines. The fix involves moving the lock around to protect the check against the thread count and correctly dealing with thread creation failure. This fix also _mostly_ repairs a race condition on how quickly the threads are created. The original intent was to create a pdflush thread (up to the max allowed) every second. Without this patch is is possible to create NCPUS pdflush threads concurrently. The 'mostly' caveat is because an assumption is made that thread creation will be successful. If we fail to create the thread, the miss is not considered fatal. (we will try again in 1 second) Signed-off-by: Peter W Morreale <pmorreale@novell.com> Reviewed-by: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-06percpu: __percpu_depopulate_mask can take a const maskStephen Rothwell
This eliminates a compiler warning: mm/allocpercpu.c: In function 'free_percpu': mm/allocpercpu.c:146: warning: passing argument 2 of '__percpu_depopulate_mask' discards qualifiers from pointer target type Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-06Merge branch 'kmemtrace-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'kmemtrace-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: kmemtrace: trace kfree() calls with NULL or zero-length objects kmemtrace: small cleanups kmemtrace: restore original tracing data binary format, improve ABI kmemtrace: kmemtrace_alloc() must fill type_id kmemtrace: use tracepoints kmemtrace, rcu: don't include unnecessary headers, allow kmemtrace w/ tracepoints kmemtrace, rcu: fix rcupreempt.c data structure dependencies kmemtrace, rcu: fix rcu_tree_trace.c data structure dependencies kmemtrace, rcu: fix linux/rcutree.h and linux/rcuclassic.h dependencies kmemtrace, mm: fix slab.h dependency problem in mm/failslab.c kmemtrace, kbuild: fix slab.h dependency problem in lib/decompress_unlzma.c kmemtrace, kbuild: fix slab.h dependency problem in lib/decompress_bunzip2.c kmemtrace, kbuild: fix slab.h dependency problem in lib/decompress_inflate.c kmemtrace, squashfs: fix slab.h dependency problem in squasfs kmemtrace, befs: fix slab.h dependency problem kmemtrace, security: fix linux/key.h header file dependencies kmemtrace, fs: fix linux/fdtable.h header file dependencies kmemtrace, fs: uninline simple_transaction_set() kmemtrace, fs, security: move alloc_secdata() and free_secdata() to linux/security.h
2009-04-06block: change the request allocation/congestion logic to be sync/async basedJens Axboe
This makes sure that we never wait on async IO for sync requests, instead of doing the split on writes vs reads. Signed-off-by: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-05Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging-2.6: (714 commits) Staging: sxg: slicoss: Specify the license for Sahara SXG and Slicoss drivers Staging: serqt_usb: fix build due to proc tty changes Staging: serqt_usb: fix checkpatch errors Staging: serqt_usb: add TODO file Staging: serqt_usb: Lindent the code Staging: add USB serial Quatech driver staging: document that the wifi staging drivers a bit better Staging: echo cleanup Staging: BUG to BUG_ON changes Staging: remove some pointless conditionals before kfree_skb() Staging: line6: fix build error, select SND_RAWMIDI Staging: line6: fix checkpatch errors in variax.c Staging: line6: fix checkpatch errors in toneport.c Staging: line6: fix checkpatch errors in pcm.c Staging: line6: fix checkpatch errors in midibuf.c Staging: line6: fix checkpatch errors in midi.c Staging: line6: fix checkpatch errors in dumprequest.c Staging: line6: fix checkpatch errors in driver.c Staging: line6: fix checkpatch errors in audio.c Staging: line6: fix checkpatch errors in pod.c ...
2009-04-05Merge branch 'tracing-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (413 commits) tracing, net: fix net tree and tracing tree merge interaction tracing, powerpc: fix powerpc tree and tracing tree interaction ring-buffer: do not remove reader page from list on ring buffer free function-graph: allow unregistering twice trace: make argument 'mem' of trace_seq_putmem() const tracing: add missing 'extern' keywords to trace_output.h tracing: provide trace_seq_reserve() blktrace: print out BLK_TN_MESSAGE properly blktrace: extract duplidate code blktrace: fix memory leak when freeing struct blk_io_trace blktrace: fix blk_probes_ref chaos blktrace: make classic output more classic blktrace: fix off-by-one bug blktrace: fix the original blktrace blktrace: fix a race when creating blk_tree_root in debugfs blktrace: fix timestamp in binary output tracing, Text Edit Lock: cleanup tracing: filter fix for TRACE_EVENT_FORMAT events ftrace: Using FTRACE_WARN_ON() to check "freed record" in ftrace_release() x86: kretprobe-booster interrupt emulation code fix ... Fix up trivial conflicts in arch/parisc/include/asm/ftrace.h include/linux/memory.h kernel/extable.c kernel/module.c
2009-04-05Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-cpumaskLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-cpumask: (36 commits) cpumask: remove cpumask allocation from idle_balance, fix numa, cpumask: move numa_node_id default implementation to topology.h, fix cpumask: remove cpumask allocation from idle_balance x86: cpumask: x86 mmio-mod.c use cpumask_var_t for downed_cpus x86: cpumask: update 32-bit APM not to mug current->cpus_allowed x86: microcode: cleanup x86: cpumask: use work_on_cpu in arch/x86/kernel/microcode_core.c cpumask: fix CONFIG_CPUMASK_OFFSTACK=y cpu hotunplug crash numa, cpumask: move numa_node_id default implementation to topology.h cpumask: convert node_to_cpumask_map[] to cpumask_var_t cpumask: remove x86 cpumask_t uses. cpumask: use cpumask_var_t in uv_flush_tlb_others. cpumask: remove cpumask_t assignment from vector_allocation_domain() cpumask: make Xen use the new operators. cpumask: clean up summit's send_IPI functions cpumask: use new cpumask functions throughout x86 x86: unify cpu_callin_mask/cpu_callout_mask/cpu_initialized_mask/cpu_sibling_setup_mask cpumask: convert struct cpuinfo_x86's llc_shared_map to cpumask_var_t cpumask: convert node_to_cpumask_map[] to cpumask_var_t x86: unify 32 and 64-bit node_to_cpumask_map ...
2009-04-03Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (28 commits) trivial: Update my email address trivial: NULL noise: drivers/mtd/tests/mtd_*test.c trivial: NULL noise: drivers/media/dvb/frontends/drx397xD_fw.h trivial: Fix misspelling of "Celsius". trivial: remove unused variable 'path' in alloc_file() trivial: fix a pdlfush -> pdflush typo in comment trivial: jbd header comment typo fix for JBD_PARANOID_IOFAIL trivial: wusb: Storage class should be before const qualifier trivial: drivers/char/bsr.c: Storage class should be before const qualifier trivial: h8300: Storage class should be before const qualifier trivial: fix where cgroup documentation is not correctly referred to trivial: Give the right path in Documentation example trivial: MTD: remove EOL from MODULE_DESCRIPTION trivial: Fix typo in bio_split()'s documentation trivial: PWM: fix of #endif comment trivial: fix typos/grammar errors in Kconfig texts trivial: Fix misspelling of firmware trivial: cgroups: documentation typo and spelling corrections trivial: Update contact info for Jochen Hein trivial: fix typo "resgister" -> "register" ...
2009-04-03Staging: pohmelfs: kconfig/makefile and vfs changes.Evgeniy Polyakov
This patch adds Kconfig and Makefile entries and exports to VFS functions to be used by POHMELFS. Signed-off-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-04-03CacheFiles: Permit the page lock state to be monitoredDavid Howells
Add a function to install a monitor on the page lock waitqueue for a particular page, thus allowing the page being unlocked to be detected. This is used by CacheFiles to detect read completion on a page in the backing filesystem so that it can then copy the data to the waiting netfs page. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Steve Dickson <steved@redhat.com> Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Tested-by: Daire Byrne <Daire.Byrne@framestore.com>
2009-04-03FS-Cache: Recruit a page flags for cache managementDavid Howells
Recruit a page flag to aid in cache management. The following extra flag is defined: (1) PG_fscache (PG_private_2) The marked page is backed by a local cache and is pinning resources in the cache driver. If PG_fscache is set, then things that checked for PG_private will now also check for that. This includes things like truncation and page invalidation. The function page_has_private() had been added to make the checks for both PG_private and PG_private_2 at the same time. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Steve Dickson <steved@redhat.com> Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Tested-by: Daire Byrne <Daire.Byrne@framestore.com>
2009-04-03FS-Cache: Release page->private after failed readaheadDavid Howells
The attached patch causes read_cache_pages() to release page-private data on a page for which add_to_page_cache() fails. If the filler function fails, then the problematic page is left attached to the pagecache (with appropriate flags set, one presumes) and the remaining to-be-attached pages are invalidated and discarded. This permits pages with caching references associated with them to be cleaned up. The invalidatepage() address space op is called (indirectly) to do the honours. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Steve Dickson <steved@redhat.com> Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Tested-by: Daire Byrne <Daire.Byrne@framestore.com>
2009-04-03kmemtrace: trace kfree() calls with NULL or zero-length objectsPekka Enberg
Impact: also output kfree(NULL) entries This patch moves the trace_kfree() calls before the ZERO_OR_NULL_PTR check so that we can trace call-sites that call kfree() with NULL many times which might be an indication of a bug. Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> LKML-Reference: <1237971957.30175.18.camel@penberg-laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-03kmemtrace: use tracepointsEduard - Gabriel Munteanu
kmemtrace now uses tracepoints instead of markers. We no longer need to use format specifiers to pass arguments. Signed-off-by: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> [ folded: Use the new TP_PROTO and TP_ARGS to fix the build. ] [ folded: fix build when CONFIG_KMEMTRACE is disabled. ] [ folded: define tracepoints when CONFIG_TRACEPOINTS is enabled. ] Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> LKML-Reference: <ae61c0f37156db8ec8dc0d5778018edde60a92e3.1237813499.git.eduard.munteanu@linux360.ro> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-03kmemtrace, mm: fix slab.h dependency problem in mm/failslab.cPekka Enberg
Impact: cleanup mm/failslab.c depends on slab.h without including it: CC mm/failslab.o mm/failslab.c: In function ‘should_failslab’: mm/failslab.c:16: error: ‘__GFP_NOFAIL’ undeclared (first use in this function) mm/failslab.c:16: error: (Each undeclared identifier is reported only once mm/failslab.c:16: error: for each function it appears in.) mm/failslab.c:19: error: ‘__GFP_WAIT’ undeclared (first use in this function) make[1]: *** [mm/failslab.o] Error 1 make: *** [mm] Error 2 It gets included implicitly currently - but this will not be the case with upcoming kmemtrace changes. Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> LKML-Reference: <1237888761.25315.69.camel@penberg-laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-02memcg: cleanup cache_chargeDaisuke Nishimura
Current mem_cgroup_cache_charge is a bit complicated especially in the case of shmem's swap-in. This patch cleans it up by using try_charge_swapin and commit_charge_swapin. Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-02memcg: remove redundant message at swaponKAMEZAWA Hiroyuki
It's pointed out that swap_cgroup's message at swapon() is nonsense. Because * It can be calculated very easily if all necessary information is written in Kconfig. * It's not necessary to annoying people at every swapon(). In other view, now, memory usage per swp_entry is reduced to 2bytes from 8bytes(64bit) and I think it's reasonably small. Reported-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-02cgroups: use css id in swap cgroup for saving memory v5KAMEZAWA Hiroyuki
Try to use CSS ID for records in swap_cgroup. By this, on 64bit machine, size of swap_cgroup goes down to 2 bytes from 8bytes. This means, when 2GB of swap is equipped, (assume the page size is 4096bytes) From size of swap_cgroup = 2G/4k * 8 = 4Mbytes. To size of swap_cgroup = 2G/4k * 2 = 1Mbytes. Reduction is large. Of course, there are trade-offs. This CSS ID will add overhead to swap-in/swap-out/swap-free. But in general, - swap is a resource which the user tend to avoid use. - If swap is never used, swap_cgroup area is not used. - Reading traditional manuals, size of swap should be proportional to size of memory. Memory size of machine is increasing now. I think reducing size of swap_cgroup makes sense. Note: - ID->CSS lookup routine has no locks, it's under RCU-Read-Side. - memcg can be obsolete at rmdir() but not freed while refcnt from swap_cgroup is available. Changelog v4->v5: - reworked on to memcg-charge-swapcache-to-proper-memcg.patch Changlog ->v4: - fixed not configured case. - deleted unnecessary comments. - fixed NULL pointer bug. - fixed message in dmesg. [nishimura@mxp.nes.nec.co.jp: css_tryget can be called twice in !PageCgroupUsed case] Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-02memcg: charge swapcache to proper memcgDaisuke Nishimura
memcg_test.txt says at 4.1: This swap-in is one of the most complicated work. In do_swap_page(), following events occur when pte is unchanged. (1) the page (SwapCache) is looked up. (2) lock_page() (3) try_charge_swapin() (4) reuse_swap_page() (may call delete_swap_cache()) (5) commit_charge_swapin() (6) swap_free(). Considering following situation for example. (A) The page has not been charged before (2) and reuse_swap_page() doesn't call delete_from_swap_cache(). (B) The page has not been charged before (2) and reuse_swap_page() calls delete_from_swap_cache(). (C) The page has been charged before (2) and reuse_swap_page() doesn't call delete_from_swap_cache(). (D) The page has been charged before (2) and reuse_swap_page() calls delete_from_swap_cache(). memory.usage/memsw.usage changes to this page/swp_entry will be Case (A) (B) (C) (D) Event Before (2) 0/ 1 0/ 1 1/ 1 1/ 1 =========================================== (3) +1/+1 +1/+1 +1/+1 +1/+1 (4) - 0/ 0 - -1/ 0 (5) 0/-1 0/ 0 -1/-1 0/ 0 (6) - 0/-1 - 0/-1 =========================================== Result 1/ 1 1/ 1 1/ 1 1/ 1 In any cases, charges to this page should be 1/ 1. In case of (D), mem_cgroup_try_get_from_swapcache() returns NULL (because lookup_swap_cgroup() returns NULL), so "+1/+1" at (3) means charges to the memcg("foo") to which the "current" belongs. OTOH, "-1/0" at (4) and "0/-1" at (6) means uncharges from the memcg("baa") to which the page has been charged. So, if the "foo" and "baa" is different(for example because of task move), this charge will be moved from "baa" to "foo". I think this is an unexpected behavior. This patch fixes this by modifying mem_cgroup_try_get_from_swapcache() to return the memcg to which the swapcache has been charged if PCG_USED bit is set. IIUC, checking PCG_USED bit of swapcache is safe under page lock. Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-02memcg: remove mem_cgroup_calc_mapped_ratio()KOSAKI Motohiro
Currently, mem_cgroup_calc_mapped_ratio() is unused at all. it can be removed and KAMEZAWA-san suggested it. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-02memcg: show memcg information during OOMBalbir Singh
Add RSS and swap to OOM output from memcg Display memcg values like failcnt, usage and limit when an OOM occurs due to memcg. Thanks to Johannes Weiner, Li Zefan, David Rientjes, Kamezawa Hiroyuki, Daisuke Nishimura and KOSAKI Motohiro for review. Sample output ------------- Task in /a/x killed as a result of limit of /a memory: usage 1048576kB, limit 1048576kB, failcnt 4183 memory+swap: usage 1400964kB, limit 9007199254740991kB, failcnt 0 [akpm@linux-foundation.org: compilation fix] [akpm@linux-foundation.org: fix kerneldoc and whitespace] [akpm@linux-foundation.org: add printk facility level] Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-02memcg: fix OOM killer under memcgKAMEZAWA Hiroyuki
This patch tries to fix OOM Killer problems caused by hierarchy. Now, memcg itself has OOM KILL function (in oom_kill.c) and tries to kill a task in memcg. But, when hierarchy is used, it's broken and correct task cannot be killed. For example, in following cgroup /groupA/ hierarchy=1, limit=1G, 01 nolimit 02 nolimit All tasks' memory usage under /groupA, /groupA/01, groupA/02 is limited to groupA's 1Gbytes but OOM Killer just kills tasks in groupA. This patch provides makes the bad process be selected from all tasks under hierarchy. BTW, currently, oom_jiffies is updated against groupA in above case. oom_jiffies of tree should be updated. To see how oom_jiffies is used, please check mem_cgroup_oom_called() callers. [akpm@linux-foundation.org: build fix] [akpm@linux-foundation.org: const fix] Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-02memcg: fix shrinking memory to return -EBUSY by fixing retry algorithmKAMEZAWA Hiroyuki
As pointed out, shrinking memcg's limit should return -EBUSY after reasonable retries. This patch tries to fix the current behavior of shrink_usage. Before looking into "shrink should return -EBUSY" problem, we should fix hierarchical reclaim code. It compares current usage and current limit, but it only makes sense when the kernel reclaims memory because hit limits. This is also a problem. What this patch does are. 1. add new argument "shrink" to hierarchical reclaim. If "shrink==true", hierarchical reclaim returns immediately and the caller checks the kernel should shrink more or not. (At shrinking memory, usage is always smaller than limit. So check for usage < limit is useless.) 2. For adjusting to above change, 2 changes in "shrink"'s retry path. 2-a. retry_count depends on # of children because the kernel visits the children under hierarchy one by one. 2-b. rather than checking return value of hierarchical_reclaim's progress, compares usage-before-shrink and usage-after-shrink. If usage-before-shrink <= usage-after-shrink, retry_count is decremented. Reported-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-02memcg: hierarchical statKAMEZAWA Hiroyuki
Clean up memory.stat file routine and show "total" hierarchical stat. This patch does - renamed get_all_zonestat to be get_local_zonestat. - remove old mem_cgroup_stat_desc, which is only for per-cpu stat. - add mcs_stat to cover both of per-cpu/per-lru stat. - add "total" stat of hierarchy (*) - add a callback system to scan all memcg under a root. == "total" is added. [kamezawa@localhost ~]$ cat /opt/cgroup/xxx/memory.stat cache 0 rss 0 pgpgin 0 pgpgout 0 inactive_anon 0 active_anon 0 inactive_file 0 active_file 0 unevictable 0 hierarchical_memory_limit 50331648 hierarchical_memsw_limit 9223372036854775807 total_cache 65536 total_rss 192512 total_pgpgin 218 total_pgpgout 155 total_inactive_anon 0 total_active_anon 135168 total_inactive_file 61440 total_active_file 4096 total_unevictable 0 == (*) maybe the user can do calc hierarchical stat by his own program in userland but if it can be written in clean way, it's worth to be shown, I think. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-02memcg: use CSS IDKAMEZAWA Hiroyuki
Assigning CSS ID for each memcg and use css_get_next() for scanning hierarchy. Assume folloing tree. group_A (ID=3) /01 (ID=4) /0A (ID=7) /02 (ID=10) group_B (ID=5) and task in group_A/01/0A hits limit at group_A. reclaim will be done in following order (round-robin). group_A(3) -> group_A/01 (4) -> group_A/01/0A (7) -> group_A/02(10) -> group_A -> ..... Round robin by ID. The last visited cgroup is recorded and restart from it when it start reclaim again. (More smart algorithm can be implemented..) No cgroup_mutex or hierarchy_mutex is required. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-02cgroup: fix frequent -EBUSY at rmdirKAMEZAWA Hiroyuki
In following situation, with memory subsystem, /groupA use_hierarchy==1 /01 some tasks /02 some tasks /03 some tasks /04 empty When tasks under 01/02/03 hit limit on /groupA, hierarchical reclaim is triggered and the kernel walks tree under groupA. In this case, rmdir /groupA/04 fails with -EBUSY frequently because of temporal refcnt from the kernel. In general. cgroup can be rmdir'd if there are no children groups and no tasks. Frequent fails of rmdir() is not useful to users. (And the reason for -EBUSY is unknown to users.....in most cases) This patch tries to modify above behavior, by - retries if css_refcnt is got by someone. - add "return value" to pre_destroy() and allows subsystem to say "we're really busy!" Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>