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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/