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author | Jens Axboe <jens.axboe@oracle.com> | 2008-12-15 15:19:25 -0500 |
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committer | Jens Axboe <jens.axboe@oracle.com> | 2008-12-29 02:29:52 -0500 |
commit | 62c1fe9d9f0a676fce89185b1513f0e5f473c72c (patch) | |
tree | 28085a657fa93ed63b7dda20b5a84885e67d429e /virt/kvm | |
parent | 8ae30b895805a6e2bb725b1d78b12daabd7eadfe (diff) |
cfq-iosched: fix race between exiting queue and exiting task
Original patch from Nikanth Karthikesan <knikanth@suse.de>
When a queue exits the queue lock is taken and cfq_exit_queue() would free all
the cic's associated with the queue.
But when a task exits, cfq_exit_io_context() gets cic one by one and then
locks the associated queue to call __cfq_exit_single_io_context. It looks like
between getting a cic from the ioc and locking the queue, the queue might have
exited on another cpu.
Fix this by rechecking the cfq_io_context queue key inside the queue lock
again, and not calling into __cfq_exit_single_io_context() if somebody
beat us to it.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'virt/kvm')
0 files changed, 0 insertions, 0 deletions