https://github.com/torvalds/linux
Revision 9a2bd244e18ffbb96c8b783210fda4eded7c7e6f authored by Brian King on 09 December 2008, 14:47:00 UTC, committed by Ingo Molnar on 09 December 2008, 18:27:03 UTC
Impact: fix possible deadlock in CPU hot-remove path This patch fixes a possible deadlock scenario in the CPU remove path. migration_call grabs rq->lock, then wakes up everything on rq->migration_queue with the lock held. Then one of the tasks on the migration queue ends up calling tg_shares_up which then also tries to acquire the same rq->lock. [c000000058eab2e0] c000000000502078 ._spin_lock_irqsave+0x98/0xf0 [c000000058eab370] c00000000008011c .tg_shares_up+0x10c/0x20c [c000000058eab430] c00000000007867c .walk_tg_tree+0xc4/0xfc [c000000058eab4d0] c0000000000840c8 .try_to_wake_up+0xb0/0x3c4 [c000000058eab590] c0000000000799a0 .__wake_up_common+0x6c/0xe0 [c000000058eab640] c00000000007ada4 .complete+0x54/0x80 [c000000058eab6e0] c000000000509fa8 .migration_call+0x5fc/0x6f8 [c000000058eab7c0] c000000000504074 .notifier_call_chain+0x68/0xe0 [c000000058eab860] c000000000506568 ._cpu_down+0x2b0/0x3f4 [c000000058eaba60] c000000000506750 .cpu_down+0xa4/0x108 [c000000058eabb10] c000000000507e54 .store_online+0x44/0xa8 [c000000058eabba0] c000000000396260 .sysdev_store+0x3c/0x50 [c000000058eabc10] c0000000001a39b8 .sysfs_write_file+0x124/0x18c [c000000058eabcd0] c00000000013061c .vfs_write+0xd0/0x1bc [c000000058eabd70] c0000000001308a4 .sys_write+0x68/0x114 [c000000058eabe30] c0000000000086b4 syscall_exit+0x0/0x40 Signed-off-by: Brian King <brking@linux.vnet.ibm.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
1 parent 4371453
Tip revision: 9a2bd244e18ffbb96c8b783210fda4eded7c7e6f authored by Brian King on 09 December 2008, 14:47:00 UTC
sched: CPU remove deadlock fix
sched: CPU remove deadlock fix
Tip revision: 9a2bd24
File | Mode | Size |
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Documentation | ||
arch | ||
block | ||
crypto | ||
drivers | ||
firmware | ||
fs | ||
include | ||
init | ||
ipc | ||
kernel | ||
lib | ||
mm | ||
net | ||
samples | ||
scripts | ||
security | ||
sound | ||
usr | ||
virt | ||
.gitignore | -rw-r--r-- | 867 bytes |
.mailmap | -rw-r--r-- | 3.8 KB |
COPYING | -rw-r--r-- | 18.3 KB |
CREDITS | -rw-r--r-- | 91.0 KB |
Kbuild | -rw-r--r-- | 2.4 KB |
MAINTAINERS | -rw-r--r-- | 103.3 KB |
Makefile | -rw-r--r-- | 55.9 KB |
README | -rw-r--r-- | 16.5 KB |
REPORTING-BUGS | -rw-r--r-- | 3.1 KB |
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