> -----Original Message----- > From: Artem Bityutskiy [mailto:dedekind1@xxxxxxxxx] > Sent: Monday, March 19, 2018 8:12 PM > To: hch@xxxxxx; Thomas Gleixner > Cc: linux-block@xxxxxxxxxxxxxxx; snitzer@xxxxxxxxxx; hare@xxxxxxx; > mroos@xxxxxxxx; linux-scsi@xxxxxxxxxxxxxxx; don.brace@xxxxxxxxxxxxx; > pbonzini@xxxxxxxxxx; loberman@xxxxxxxxxx; > kashyap.desai@xxxxxxxxxxxx; Jens Axboe; martin.petersen@xxxxxxxxxx; > James.Bottomley@xxxxxxxxxxxxxxxxxxxxx; ming.lei@xxxxxxxxxx > 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: > > 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.
