-----Original Message-----
From: Artem Bityutskiy [mailto:dedekind1@gmail.com]
Sent: Monday, March 19, 2018 8:12 PM
To: hch@lst.de; Thomas Gleixner
Cc: linux-block@vger.kernel.org; snitzer@redhat.com; hare@suse.de;
mroos@linux.ee; linux-scsi@vger.kernel.org; don.brace@microsemi.com;
pbonzini@redhat.com; loberman@redhat.com;
kashyap.desai@broadcom.com; Jens Axboe; martin.petersen@oracle.com;
James.Bottomley@HansenPartnership.com; ming.lei@redhat.com
Subject: Re: [PATCH V5 1/5] scsi: hpsa: fix selection of reply queue

On Mon, 2018-03-19 at 08:31 -0600, Jens Axboe wrote:

quoted

I'm assuming that Martin will eventually queue this up. But probably
for 4.17, then we can always flag it for a backport to stable once
it's been thoroughly tested.

Jens, thanks for reply.

I wonder if folks agree that in this case we should revert

84676c1f21e8 genirq/affinity: assign vectors to all possible CPUs

for v4.16.

If this was a minor niche use-case regression the -stable scenario would
probably be OK. But the patch seem to miss the fact that kernel's
"possible
CPUs" notion may be way off and side effects are bad.

Also it is performance issue as posted at below link, if we just use
"84676c1f21e8 genirq/affinity: assign vectors to all possible CPUs".

https://www.spinics.net/lists/linux-scsi/msg118301.html

Performance drop was resolved using patch set (available at below link)under
discussion posted by Ming.

https://marc.info/?l=linux-block&m=152050646332092&w=2

Kashyap

Christoph, Thomas, what do you think?

Thanks,
Artem.