From mboxrd@z Thu Jan 1 00:00:00 1970 From: axboe@fb.com (Jens Axboe) Date: Wed, 23 Sep 2015 14:40:21 -0600 Subject: [PATCH] NVMe: Set affinity after allocating request queues In-Reply-To: References: <1441289897-16839-1-git-send-email-keith.busch@intel.com> Message-ID: <56030E35.3060400@fb.com> On 09/23/2015 02:37 PM, Keith Busch wrote: > On Thu, 3 Sep 2015, Keith Busch wrote: >> The asynchronous namespace scanning caused affinity hints to be set >> before >> its tagset initialized, so there was no cpu mask to set the hint. This >> patch moves the affinity hint setting to after namespaces are scanned. > > Hi Jens, > > Would it be okay to get this merged in for 4.3? The affinity hint is > very important to top out performance, so this should be considered a > bug that the setting wasn't correct. I haven't seen this patch, but yes if it's not setting the right hints, then it should be fixed as that is certainly a potentially big performance issue. In general we're still in dire need of having a proper way of having this done without a lot of driver interaction. I'd really love to see a framework that just has the driver ask blk-mq for a set of handlers, and blk-mq will set with the hints that it has already assigned. I might even have promised to write this, I should get around to do that... But I don't think it should be a gating factor for this fix, though it still needs to get done. -- Jens Axboe