On 10/08/2020 17:38, Kashyap Desai wrote:

Functional Test -

I cover overnight IO testing using <fio> script which sends 4K rand read,
read, rand write and write IOs to the 24 SAS JBOD drives.
Some of the JBOD has ioscheduler=none and some of the JBOD has
ioscheduler=mq-deadline
I used additional script which change sdev->queue_depth of each device
from 2 to 16 range at the interval of 5 seconds.
I used additional script which toggle "rq_affinity=1" and "rq_affinity=2"
at the interval of 5 seconds.

I did not noticed any IO hang.

Thanks, Kashyap

Nice work. I think v8 series can now be prepared, since this final 
performance issue reported looks resolved. But I still don't know what's 
going on for "[PATCHv6 00/21] scsi: enable reserved commands for LLDDs", 
which current hpsa patch relies on for basic functionality :(

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 From 06993ddf5c5dbe0e772cc38342919eb61a57bc50 Mon Sep 17 00:00:00
2001
From: Ming Lei<redacted>
Date: Wed, 5 Aug 2020 16:35:53 +0800
Subject: [PATCH] scsi: core: only re-run queue in scsi_end_request() if

device

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queue is busy

Ming, I assume that you will send this directly to SCSI maintainers when 
the merge window closes.

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Now the request queue is run in scsi_end_request() unconditionally if

both

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target queue and host queue is ready. We should have re-run request

queue

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only after this device queue becomes busy for restarting this LUN only.

Recently Long Li reported that cost of run queue may be very heavy in

case of

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high queue depth. So improve this situation by only running the request

queue

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when this LUN is busy.