Messages in this thread | ![/](/images/icornerl.gif) | | Date | Wed, 18 Jan 2023 18:42:08 +0100 | From | Christoph Hellwig <> | Subject | Re: [PATCH v4 12/14] blk-mq: remove set of bd->last when get driver tag for next request fails |
| |
On Wed, Jan 18, 2023 at 05:37:24PM +0800, Kemeng Shi wrote: > Commit 113285b473824 ("blk-mq: ensure that bd->last is always set > correctly") will set last if we failed to get driver tag for next > request to avoid flush miss as we break the list walk and will not > send the last request in the list which will be sent with last set > normally. > This code seems stale now becase the flush introduced is always > redundant as: > For case tag is really out, we will send a extra flush if we find > list is not empty after list walk. > For case some tag is freed before retry in blk_mq_prep_dispatch_rq for > next, then we can get a tag for next request in retry and flush notified > already is not necessary.
I think Ming will know this code better than me, but aren't we losing the blk_mq_get_driver_tag call entirely here now. Where is getting the driver tag covered now?
| ![\](/images/icornerr.gif) |