From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f70.google.com (mail-wm0-f70.google.com [74.125.82.70]) by kanga.kvack.org (Postfix) with ESMTP id 8D4C16B0069 for ; Thu, 1 Dec 2016 09:11:28 -0500 (EST) Received: by mail-wm0-f70.google.com with SMTP id a20so57445408wme.5 for ; Thu, 01 Dec 2016 06:11:28 -0800 (PST) Received: from mail-wm0-f67.google.com (mail-wm0-f67.google.com. [74.125.82.67]) by mx.google.com with ESMTPS id t14si12171953wme.122.2016.12.01.06.11.27 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 01 Dec 2016 06:11:27 -0800 (PST) Received: by mail-wm0-f67.google.com with SMTP id a20so34487208wme.2 for ; Thu, 01 Dec 2016 06:11:27 -0800 (PST) Date: Thu, 1 Dec 2016 15:11:25 +0100 From: Michal Hocko Subject: Re: drm/radeon spamming alloc_contig_range: [xxx, yyy) PFNs busy busy Message-ID: <20161201141125.GB20966@dhcp22.suse.cz> References: <20161130092239.GD18437@dhcp22.suse.cz> <20161130132848.GG18432@dhcp22.suse.cz> <20161201071507.GC18272@dhcp22.suse.cz> <20161201072119.GD18272@dhcp22.suse.cz> <9f2aa4e4-d7d5-e24f-112e-a4b43f0a0ccc@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <9f2aa4e4-d7d5-e24f-112e-a4b43f0a0ccc@suse.cz> Sender: owner-linux-mm@kvack.org List-ID: To: Vlastimil Babka Cc: "Robin H. Johnson" , Michal Nazarewicz , linux-kernel@vger.kernel.org, linux-mm@kvack.org, dri-devel@lists.freedesktop.org, Joonsoo Kim , Marek Szyprowski Let's also CC Marek On Thu 01-12-16 08:43:40, Vlastimil Babka wrote: > On 12/01/2016 08:21 AM, Michal Hocko wrote: > > Forgot to CC Joonsoo. The email thread starts more or less here > > http://lkml.kernel.org/r/20161130092239.GD18437@dhcp22.suse.cz > > > > On Thu 01-12-16 08:15:07, Michal Hocko wrote: > > > On Wed 30-11-16 20:19:03, Robin H. Johnson wrote: > > > [...] > > > > alloc_contig_range: [83f2a3, 83f2a4) PFNs busy > > > > > > Huh, do I get it right that the request was for a _single_ page? Why do > > > we need CMA for that? > > Ugh, good point. I assumed that was just the PFNs that it failed to migrate > away, but it seems that's indeed the whole requested range. Yeah sounds some > part of the dma-cma chain could be smarter and attempt CMA only for e.g. > costly orders. Is there any reason why the DMA api doesn't try the page allocator first before falling back to the CMA? I simply have a hard time to see why the CMA should be used (and fragment) for small requests size. -- Michal Hocko SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org