Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751530AbaLCK06 (ORCPT ); Wed, 3 Dec 2014 05:26:58 -0500 Received: from cantor2.suse.de ([195.135.220.15]:53465 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750862AbaLCK04 (ORCPT ); Wed, 3 Dec 2014 05:26:56 -0500 Date: Wed, 3 Dec 2014 11:26:52 +0100 From: Joerg Roedel To: Konrad Rzeszutek Wilk Cc: Joerg Roedel , Ingo Molnar , Thomas Gleixner , "H. Peter Anvin" , x86@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/3] swiotlb: Warn on allocation failure in swiotlb_alloc_coherent Message-ID: <20141203102652.GL3156@suse.de> References: <1417174149-31210-1-git-send-email-joro@8bytes.org> <1417174149-31210-2-git-send-email-joro@8bytes.org> <20141201202802.GC21626@laptop.dumpdata.com> <20141202144122.GI3156@suse.de> <20141202184615.GA32622@laptop.dumpdata.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20141202184615.GA32622@laptop.dumpdata.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Dec 02, 2014 at 01:46:15PM -0500, Konrad Rzeszutek Wilk wrote: > On Tue, Dec 02, 2014 at 03:41:22PM +0100, Joerg Roedel wrote: > > On Mon, Dec 01, 2014 at 03:28:03PM -0500, Konrad Rzeszutek Wilk wrote: > > > On Fri, Nov 28, 2014 at 12:29:07PM +0100, Joerg Roedel wrote: > > > > From: Joerg Roedel > > > > > > > > Print a warning when all allocation tries have been failed > > > > and the function is about to return NULL. This prepares for > > > > calling the function with __GFP_NOWARN to suppress > > > > allocation failure warnings before all fall-backs have > > > > failed. > > > > > > This can be quite noisy. Especially the dump-stack. > > > > Well, this is as noisy as the dump_stack()s from the page-allocator when > > the first allocation try fails. The goal of the first two patches in > > Right, on the first allocation. Subsequent allocations won't be so noisy > in the page-allocator (I think?). >From the code in mm/page_alloc.c (function warn_alloc_failed) it doesn't look like a one-time warning. The dmesg I have seen from a failing kernel also shows a lot of these messages. So having the warning at the end of swiotlb_alloc_coherent won't be any more noisy than the (removed) warnings from the page allocator. Joerg -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/