Re: [PATCH V3 0/7] blk-mq: don't allocate driver tag beforehand for flush rq

From: Ming Lei
Date: Sat Nov 04 2017 - 00:17:36 EST


On Thu, Nov 02, 2017 at 11:24:31PM +0800, Ming Lei wrote:
> Hi Jens,
>
> This patchset avoids to allocate driver tag beforehand for flush rq
> in case of I/O scheduler, then flush rq isn't treated specially
> wrt. get/put driver tag, code gets cleanup much, such as,
> reorder_tags_to_front() is removed, and we needn't to worry
> about request order in dispatch list for avoiding I/O deadlock.
>
> 'dbench -t 30 -s 64' has been run on different devices(shared tag,
> multi-queue, singele queue, ...), and no issues are observed,
> even very low queue depth test are run, debench still works well.
>
> Please consider it for V4.15, thanks!

Hi Jens,

As we discussed before, this patch is a good cleanup on handling flush
request, could you share your opinion on V3?

thanks,
Ming