Hi Roger, On 06/23/2017 08:57 PM, Roger Pau Monné wrote: > On Thu, Jun 22, 2017 at 09:36:52AM +0800, Junxiao Bi wrote: >> When ring buf full, hw queue will be stopped. While blkif interrupt consume >> request and make free space in ring buf, hw queue will be started again. >> But since start queue is protected by spin lock while stop not, that will >> cause a race. >> >> interrupt: process: >> blkif_interrupt() blkif_queue_rq() >> kick_pending_request_queues_locked() >> blk_mq_start_stopped_hw_queues() >> clear_bit(BLK_MQ_S_STOPPED, &hctx->state) >> blk_mq_stop_hw_queue(hctx) >> blk_mq_run_hw_queue(hctx, async) >> >> If ring buf is made empty in this case, interrupt will never come, then the >> hw queue will be stopped forever, all processes waiting for the pending io >> in the queue will hung. >> >> Signed-off-by: Junxiao Bi <junxiao...@oracle.com> >> Reviewed-by: Ankur Arora <ankur.a.ar...@oracle.com> > > Acked-by: Roger Pau Monné <roger....@citrix.com> Looks patch not in mainline. Can you please help merge it?
Thanks, Junxiao. > > Thanks, Roger. > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xen.org > https://lists.xen.org/xen-devel > _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org https://lists.xen.org/xen-devel