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author | Tejun Heo <tj@kernel.org> | 2011-11-21 12:32:23 -0800 |
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committer | Tejun Heo <tj@kernel.org> | 2011-11-21 12:32:23 -0800 |
commit | 8a32c441c1609f80e55df75422324a1151208f40 (patch) | |
tree | 73884b06cc2db3ea155af9a88815bb5105a4473e /net | |
parent | a0acae0e886d44bd5ce6d2f173c1ace0fcf0d9f6 (diff) |
freezer: implement and use kthread_freezable_should_stop()
Writeback and thinkpad_acpi have been using thaw_process() to prevent
deadlock between the freezer and kthread_stop(); unfortunately, this
is inherently racy - nothing prevents freezing from happening between
thaw_process() and kthread_stop().
This patch implements kthread_freezable_should_stop() which enters
refrigerator if necessary but is guaranteed to return if
kthread_stop() is invoked. Both thaw_process() users are converted to
use the new function.
Note that this deadlock condition exists for many of freezable
kthreads. They need to be converted to use the new should_stop or
freezable workqueue.
Tested with synthetic test case.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Henrique de Moraes Holschuh <ibm-acpi@hmh.eng.br>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Oleg Nesterov <oleg@redhat.com>
Diffstat (limited to 'net')
0 files changed, 0 insertions, 0 deletions