Re: [PATCH] blk-mq: insert rq with DONTPREP to hctx dispatch list when requeue

2019-02-11 Thread jianchao.wang
Hi Jens Thanks for your kindly response. On 2/12/19 7:20 AM, Jens Axboe wrote: > On 2/11/19 4:15 PM, Jens Axboe wrote: >> On 2/11/19 8:59 AM, Jens Axboe wrote: >>> On 2/10/19 10:41 PM, Jianchao Wang wrote: When requeue, if RQF_DONTPREP, rq has contained some driver specific data, so ins

Re: [PATCH] blk-mq: insert rq with DONTPREP to hctx dispatch list when requeue

2019-02-11 Thread Jens Axboe
On 2/11/19 4:15 PM, Jens Axboe wrote: > On 2/11/19 8:59 AM, Jens Axboe wrote: >> On 2/10/19 10:41 PM, Jianchao Wang wrote: >>> When requeue, if RQF_DONTPREP, rq has contained some driver >>> specific data, so insert it to hctx dispatch list to avoid any >>> merge. Take scsi as example, here is the

Re: [PATCH] blk-mq: insert rq with DONTPREP to hctx dispatch list when requeue

2019-02-11 Thread Jens Axboe
On 2/11/19 8:59 AM, Jens Axboe wrote: > On 2/10/19 10:41 PM, Jianchao Wang wrote: >> When requeue, if RQF_DONTPREP, rq has contained some driver >> specific data, so insert it to hctx dispatch list to avoid any >> merge. Take scsi as example, here is the trace event log (no >> io scheduler, because

Re: [PATCH] blk-mq: insert rq with DONTPREP to hctx dispatch list when requeue

2019-02-11 Thread Jens Axboe
On 2/10/19 10:41 PM, Jianchao Wang wrote: > When requeue, if RQF_DONTPREP, rq has contained some driver > specific data, so insert it to hctx dispatch list to avoid any > merge. Take scsi as example, here is the trace event log (no > io scheduler, because RQF_STARTED would prevent merging), > >

[PATCH] blk-mq: insert rq with DONTPREP to hctx dispatch list when requeue

2019-02-10 Thread Jianchao Wang
When requeue, if RQF_DONTPREP, rq has contained some driver specific data, so insert it to hctx dispatch list to avoid any merge. Take scsi as example, here is the trace event log (no io scheduler, because RQF_STARTED would prevent merging), kworker/0:1H-339 [000] ...1 2037.209289: block_rq_