From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Moyer Subject: Re: [PATCH 5/8] cfq-iosched: remove @gfp_mask from cfq_find_alloc_queue() Date: Tue, 09 Jun 2015 10:29:33 -0400 Message-ID: References: <1433753973-23684-1-git-send-email-tj@kernel.org> <1433753973-23684-6-git-send-email-tj@kernel.org> <20150609030054.GJ21465@mtj.duckdns.org> Mime-Version: 1.0 Return-path: In-Reply-To: <20150609030054.GJ21465-qYNAdHglDFBN0TnZuCh8vA@public.gmane.org> (Tejun Heo's message of "Tue, 9 Jun 2015 12:00:54 +0900") Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Tejun Heo Cc: axboe-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, vgoyal-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, avanzini.arianna-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org Tejun Heo writes: > Hey, Jeff. > > On Mon, Jun 08, 2015 at 04:27:10PM -0400, Jeff Moyer wrote: >> >> Remove @gfp_mask from cfq_find_alloc_queue() and propagate the changes >> >> to its callers. This simplifies the function quite a bit and will >> >> help making async queues per-cfq_group. >> > >> > Sorry, I disagree with this patch. You've changed it so that all cfqq >> > allocations are GFP_ATOMIC, and most, if not all of them simply don't >> > need to be. >> >> It occurs to me that replacing GFP_ATOMIC with GFP_NOWAIT in your patch >> would address my concerns, and patches 6-8 would apply almost as-is. >> What do you think about that? > > Oh yeah, it's okay to fail these allocations under memory pressure. > GFP_NOWAIT is the better pick here. It's GFP_ATOMIC mostly due to > historic copy&paste anyway. I'll change them to GFP_NOWAIT. OK. Assuming that's the only change, you can go ahead and add my Reviewed-by: Jeff Moyer to the next iteration. Thanks! Jeff