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. Roger. _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org https://lists.xen.org/xen-devel
