> On 09/12/2021 13:52, Kashyap Desai wrote: > > + scsi mailing list > > > >> On Mon, 18 Oct 2021 17:41:23 +0800, John Garry wrote: > >>> Since it is now possible for a tagset to share a single set of tags, > >>> the iter function should not re-iter the tags for the count of #hw > >>> queues in that case. Rather it should just iter once. > > John - Recently we found issue of error hander thread never kicked off > > and this patch fix the issue. > > Without this patch, scsi error hander will not find correct host_busy > > counter. > > > > Take one simple case. There is one IO outstanding and that is getting > > timedout. > > Now SML wants to wake up EH thread only if, below condition met > > "scsi_host_busy(shost) == shost->host_failed" > > > > Without this patch, shared host tag enabled meagaraid_sas driver will > > find host_busy = actual outstanding * nr_hw_queues. > > Error handler thread will never be kicked-off. > > > > This patch is mandatory for fixing shared host tag feature and require > > to be part of stable kernel. > > > > Do you need more data for posting to stable kernel ? > > To be clear, are you saying that you see the issue which patch "blk-mq: > Fix blk_mq_tagset_busy_iter() for shared tags" fixes before v5.16-rc? > > This patch (now commit 0994c64eb415) and the commit which it is supposed > to fix, e155b0c238b2, will only be in v5.16, so I don't see anything which > is > needed in stable. Hi John Yes. No need of posting this to stable. There is still an issue which we are tracking. It is not always reproducible. I am injecting artificial Task abort on my setup to reproduce it. It happens on rhel8.5 most of the time. It is a timing issue so thinking of reproducing on other kernel as well. I am suspecting issue might be due to missing commit - 67f3b2f822b7e71cfc9b42dbd9f3144fa2933e0b of [PATCH] blk-mq: avoid to iterate over stale request Whenever I notice the issue, there was a symptoms that host_busy is getting counted for each hctx individually. Let me collect more data and I will start another thread. Kashyap > > Thanks, > John
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