From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757869AbbLCHtJ (ORCPT ); Thu, 3 Dec 2015 02:49:09 -0500 Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:40854 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751446AbbLCHtH (ORCPT ); Thu, 3 Dec 2015 02:49:07 -0500 Date: Thu, 3 Dec 2015 08:49:02 +0100 From: Pavel Machek To: Chris Snook Cc: David Miller , mhocko@kernel.org, akpm@osdl.org, linux-kernel@vger.kernel.org, jcliburn@gmail.com, netdev@vger.kernel.org, rjw@rjwysocki.net, linux-mm@kvack.org, nic-devel@qualcomm.com, ronangeles@gmail.com, ebiederm@xmission.com Subject: Re: [PATCH] Improve Atheros ethernet driver not to do order 4 GFP_ATOMIC allocation Message-ID: <20151203074902.GB4139@amd> References: <20151127082010.GA2500@dhcp22.suse.cz> <20151128145113.GB4135@amd> <20151130132129.GB21950@dhcp22.suse.cz> <20151201.153517.224543138214404348.davem@davemloft.net> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed 2015-12-02 22:43:31, Chris Snook wrote: > On Tue, Dec 1, 2015 at 12:35 PM David Miller wrote: > > > From: Michal Hocko > > Date: Mon, 30 Nov 2015 14:21:29 +0100 > > > > > On Sat 28-11-15 15:51:13, Pavel Machek wrote: > > >> > > >> atl1c driver is doing order-4 allocation with GFP_ATOMIC > > >> priority. That often breaks networking after resume. Switch to > > >> GFP_KERNEL. Still not ideal, but should be significantly better. > > > > > > It is not clear why GFP_KERNEL can replace GFP_ATOMIC safely neither > > > from the changelog nor from the patch context. > > > > Earlier in the function we do a GFP_KERNEL kmalloc so: > > > > ¯\_(ツ)_/¯ > > > > It should be fine. > > > > AFAICT, the people who benefit from GFP_ATOMIC are the people running all > their storage over NFS/iSCSI who are suspending their machines while > they're so busy they don't have any clean order 4 pagecache to drop, and > want the machine to panic rather than hang. The people who benefit >from iSCSI on machine that suspends... is that a joke or complicated way of saying that noone benefits? And code uses... both GFP_ATOMIC and GFP_KERNEL so that both sides are equally unhappy? :-). Do you want to test the patch, update the subject line and send it to Davem, or should I do it? Do you see a way to split the allocation? Not even order 4 GFP_KERNEL allocation is a nice thing to do... Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Machek Subject: Re: [PATCH] Improve Atheros ethernet driver not to do order 4 GFP_ATOMIC allocation Date: Thu, 3 Dec 2015 08:49:02 +0100 Message-ID: <20151203074902.GB4139@amd> References: <20151127082010.GA2500@dhcp22.suse.cz> <20151128145113.GB4135@amd> <20151130132129.GB21950@dhcp22.suse.cz> <20151201.153517.224543138214404348.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Cc: David Miller , mhocko@kernel.org, akpm@osdl.org, linux-kernel@vger.kernel.org, jcliburn@gmail.com, netdev@vger.kernel.org, rjw@rjwysocki.net, linux-mm@kvack.org, nic-devel@qualcomm.com, ronangeles@gmail.com, ebiederm@xmission.com To: Chris Snook Return-path: Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-Id: netdev.vger.kernel.org On Wed 2015-12-02 22:43:31, Chris Snook wrote: > On Tue, Dec 1, 2015 at 12:35 PM David Miller wrot= e: >=20 > > From: Michal Hocko > > Date: Mon, 30 Nov 2015 14:21:29 +0100 > > > > > On Sat 28-11-15 15:51:13, Pavel Machek wrote: > > >> > > >> atl1c driver is doing order-4 allocation with GFP_ATOMIC > > >> priority. That often breaks networking after resume. Switch to > > >> GFP_KERNEL. Still not ideal, but should be significantly better. > > > > > > It is not clear why GFP_KERNEL can replace GFP_ATOMIC safely neithe= r > > > from the changelog nor from the patch context. > > > > Earlier in the function we do a GFP_KERNEL kmalloc so: > > > > =C2=AF\_(=E3=83=84)_/=C2=AF > > > > It should be fine. > > >=20 > AFAICT, the people who benefit from GFP_ATOMIC are the people running a= ll > their storage over NFS/iSCSI who are suspending their machines while > they're so busy they don't have any clean order 4 pagecache to drop, an= d > want the machine to panic rather than hang. The people who benefit >from iSCSI on machine that suspends... is that a joke or complicated way of saying that noone benefits? And code uses... both GFP_ATOMIC and GFP_KERNEL so that both sides are equally unhappy? :-). Do you want to test the patch, update the subject line and send it to Davem, or should I do it? Do you see a way to split the allocation? Not even order 4 GFP_KERNEL allocation is a nice thing to do... Pavel --=20 (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/b= log.html -- 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 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f54.google.com (mail-wm0-f54.google.com [74.125.82.54]) by kanga.kvack.org (Postfix) with ESMTP id 5CB1A6B0038 for ; Thu, 3 Dec 2015 02:49:06 -0500 (EST) Received: by wmvv187 with SMTP id v187so13719417wmv.1 for ; Wed, 02 Dec 2015 23:49:05 -0800 (PST) Received: from atrey.karlin.mff.cuni.cz (atrey.karlin.mff.cuni.cz. [195.113.26.193]) by mx.google.com with ESMTP id vx5si9686481wjc.219.2015.12.02.23.49.04 for ; Wed, 02 Dec 2015 23:49:05 -0800 (PST) Date: Thu, 3 Dec 2015 08:49:02 +0100 From: Pavel Machek Subject: Re: [PATCH] Improve Atheros ethernet driver not to do order 4 GFP_ATOMIC allocation Message-ID: <20151203074902.GB4139@amd> References: <20151127082010.GA2500@dhcp22.suse.cz> <20151128145113.GB4135@amd> <20151130132129.GB21950@dhcp22.suse.cz> <20151201.153517.224543138214404348.davem@davemloft.net> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: Chris Snook Cc: David Miller , mhocko@kernel.org, akpm@osdl.org, linux-kernel@vger.kernel.org, jcliburn@gmail.com, netdev@vger.kernel.org, rjw@rjwysocki.net, linux-mm@kvack.org, nic-devel@qualcomm.com, ronangeles@gmail.com, ebiederm@xmission.com On Wed 2015-12-02 22:43:31, Chris Snook wrote: > On Tue, Dec 1, 2015 at 12:35 PM David Miller wrote: > > > From: Michal Hocko > > Date: Mon, 30 Nov 2015 14:21:29 +0100 > > > > > On Sat 28-11-15 15:51:13, Pavel Machek wrote: > > >> > > >> atl1c driver is doing order-4 allocation with GFP_ATOMIC > > >> priority. That often breaks networking after resume. Switch to > > >> GFP_KERNEL. Still not ideal, but should be significantly better. > > > > > > It is not clear why GFP_KERNEL can replace GFP_ATOMIC safely neither > > > from the changelog nor from the patch context. > > > > Earlier in the function we do a GFP_KERNEL kmalloc so: > > > > A?\_(a??)_/A? > > > > It should be fine. > > > > AFAICT, the people who benefit from GFP_ATOMIC are the people running all > their storage over NFS/iSCSI who are suspending their machines while > they're so busy they don't have any clean order 4 pagecache to drop, and > want the machine to panic rather than hang. The people who benefit >from iSCSI on machine that suspends... is that a joke or complicated way of saying that noone benefits? And code uses... both GFP_ATOMIC and GFP_KERNEL so that both sides are equally unhappy? :-). Do you want to test the patch, update the subject line and send it to Davem, or should I do it? Do you see a way to split the allocation? Not even order 4 GFP_KERNEL allocation is a nice thing to do... Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -- 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