Revision b1dd693e5b9348bd68a80e679e03cf9c0973b01b authored by Daisuke Nishimura on 24 November 2010, 20:57:06 UTC, committed by Linus Torvalds on 24 November 2010, 21:50:44 UTC
__mem_cgroup_try_charge() can be called under down_write(&mmap_sem)(e.g.
mlock does it). This means it can cause deadlock if it races with move charge:
Ex.1)
move charge | try charge
--------------------------------------+------------------------------
mem_cgroup_can_attach() | down_write(&mmap_sem)
mc.moving_task = current | ..
mem_cgroup_precharge_mc() | __mem_cgroup_try_charge()
mem_cgroup_count_precharge() | prepare_to_wait()
down_read(&mmap_sem) | if (mc.moving_task)
-> cannot aquire the lock | -> true
| schedule()
Ex.2)
move charge | try charge
--------------------------------------+------------------------------
mem_cgroup_can_attach() |
mc.moving_task = current |
mem_cgroup_precharge_mc() |
mem_cgroup_count_precharge() |
down_read(&mmap_sem) |
.. |
up_read(&mmap_sem) |
| down_write(&mmap_sem)
mem_cgroup_move_task() | ..
mem_cgroup_move_charge() | __mem_cgroup_try_charge()
down_read(&mmap_sem) | prepare_to_wait()
-> cannot aquire the lock | if (mc.moving_task)
| -> true
| schedule()
To avoid this deadlock, we do all the move charge works (both can_attach() and
attach()) under one mmap_sem section.
And after this patch, we set/clear mc.moving_task outside mc.lock, because we
use the lock only to check mc.from/to.
Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent 11e7946
| File | Mode | Size |
|---|---|---|
| Kconfig | -rw-r--r-- | 9.9 KB |
| Kconfig.debug | -rw-r--r-- | 1014 bytes |
| Makefile | -rw-r--r-- | 1.6 KB |
| backing-dev.c | -rw-r--r-- | 20.9 KB |
| bootmem.c | -rw-r--r-- | 24.4 KB |
| bounce.c | -rw-r--r-- | 6.5 KB |
| compaction.c | -rw-r--r-- | 16.2 KB |
| debug-pagealloc.c | -rw-r--r-- | 2.5 KB |
| dmapool.c | -rw-r--r-- | 13.0 KB |
| fadvise.c | -rw-r--r-- | 3.5 KB |
| failslab.c | -rw-r--r-- | 1.6 KB |
| filemap.c | -rw-r--r-- | 66.4 KB |
| filemap_xip.c | -rw-r--r-- | 11.0 KB |
| fremap.c | -rw-r--r-- | 6.7 KB |
| highmem.c | -rw-r--r-- | 10.3 KB |
| hugetlb.c | -rw-r--r-- | 76.9 KB |
| hwpoison-inject.c | -rw-r--r-- | 3.3 KB |
| init-mm.c | -rw-r--r-- | 647 bytes |
| internal.h | -rw-r--r-- | 7.1 KB |
| kmemcheck.c | -rw-r--r-- | 2.8 KB |
| kmemleak-test.c | -rw-r--r-- | 3.3 KB |
| kmemleak.c | -rw-r--r-- | 49.6 KB |
| ksm.c | -rw-r--r-- | 52.5 KB |
| maccess.c | -rw-r--r-- | 1.6 KB |
| madvise.c | -rw-r--r-- | 11.3 KB |
| memblock.c | -rw-r--r-- | 22.5 KB |
| memcontrol.c | -rw-r--r-- | 126.3 KB |
| memory-failure.c | -rw-r--r-- | 38.6 KB |
| memory.c | -rw-r--r-- | 97.5 KB |
| memory_hotplug.c | -rw-r--r-- | 21.8 KB |
| mempolicy.c | -rw-r--r-- | 67.4 KB |
| mempool.c | -rw-r--r-- | 8.9 KB |
| migrate.c | -rw-r--r-- | 31.0 KB |
| mincore.c | -rw-r--r-- | 7.6 KB |
| mlock.c | -rw-r--r-- | 15.5 KB |
| mm_init.c | -rw-r--r-- | 3.7 KB |
| mmap.c | -rw-r--r-- | 69.4 KB |
| mmu_context.c | -rw-r--r-- | 1.4 KB |
| mmu_notifier.c | -rw-r--r-- | 8.8 KB |
| mmzone.c | -rw-r--r-- | 2.5 KB |
| mprotect.c | -rw-r--r-- | 7.6 KB |
| mremap.c | -rw-r--r-- | 13.0 KB |
| msync.c | -rw-r--r-- | 2.4 KB |
| nommu.c | -rw-r--r-- | 49.7 KB |
| oom_kill.c | -rw-r--r-- | 21.2 KB |
| page-writeback.c | -rw-r--r-- | 39.0 KB |
| page_alloc.c | -rw-r--r-- | 152.4 KB |
| page_cgroup.c | -rw-r--r-- | 11.4 KB |
| page_io.c | -rw-r--r-- | 3.2 KB |
| page_isolation.c | -rw-r--r-- | 3.6 KB |
| pagewalk.c | -rw-r--r-- | 4.7 KB |
| percpu-km.c | -rw-r--r-- | 2.8 KB |
| percpu-vm.c | -rw-r--r-- | 13.0 KB |
| percpu.c | -rw-r--r-- | 55.5 KB |
| prio_tree.c | -rw-r--r-- | 6.3 KB |
| quicklist.c | -rw-r--r-- | 2.4 KB |
| readahead.c | -rw-r--r-- | 15.4 KB |
| rmap.c | -rw-r--r-- | 45.4 KB |
| shmem.c | -rw-r--r-- | 71.6 KB |
| slab.c | -rw-r--r-- | 118.3 KB |
| slob.c | -rw-r--r-- | 17.2 KB |
| slub.c | -rw-r--r-- | 110.6 KB |
| sparse-vmemmap.c | -rw-r--r-- | 5.9 KB |
| sparse.c | -rw-r--r-- | 20.5 KB |
| swap.c | -rw-r--r-- | 13.0 KB |
| swap_state.c | -rw-r--r-- | 10.4 KB |
| swapfile.c | -rw-r--r-- | 65.3 KB |
| thrash.c | -rw-r--r-- | 1.9 KB |
| truncate.c | -rw-r--r-- | 16.4 KB |
| util.c | -rw-r--r-- | 7.3 KB |
| vmalloc.c | -rw-r--r-- | 62.4 KB |
| vmscan.c | -rw-r--r-- | 84.0 KB |
| vmstat.c | -rw-r--r-- | 29.3 KB |
Computing file changes ...
