Hi Konrad, On 07/19/2017 03:37 PM, Roger Pau Monné wrote: > On Wed, Jul 19, 2017 at 09:19:49AM +0800, Junxiao Bi wrote: >> 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? > > I'm afraid this needs to be done by Konrad or one of the Linux > maintainers, I don't have an account on kernel.org in order to send > pull requests to Jens. Can you pls help merge it?
Thanks, Junxiao. > > Roger. > _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org https://lists.xen.org/xen-devel
