Messages in this thread | | | From | Ming Lei <> | Subject | [PATCH v1 0/2] blk-mq: fix oops caused by CPU hotplug | Date | Tue, 21 Apr 2015 10:00:18 +0800 |
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Hi Guys,
Dongsu Park reported[1] that kernel oops can be triggered easily by CPU plug when there is pending I/O on virtio-scsi.
Turns out two problems exist in blk-mq core code and both can trigger oops by CPU plug: - timeout handling vs CPU hotplug, especially unmapped hw queue tags is still touched by timeout handler - in case of shared tags, there is one bug about setting and checking hctx->tags during CPU hotplug
The two patches fix the two problem, and Dongsu has verified that the oops is fixed with the two patches too.
[1], http://marc.info/?t=142926389200008&r=1&w=2
V1: - update comment - moving tags allocation in blk_mq_map_swqueue() because unmapped hw queue can be remapped after CPU topo is changed
block/blk-mq.c | 50 ++++++++++++++++++++++++++------------------------ 1 file changed, 26 insertions(+), 24 deletions(-)
Thanks, Ming Lei
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