Re: [PATCH] Improve Atheros ethernet driver not to do order 4 GFP_ATOMIC allocation

Path	csiph.com!eternal-september.org!feeder.eternal-september.org!aioe.org!bofh.it!news.nic.it!robomod
From	Pavel Machek <pavel@ucw.cz>
Newsgroups	linux.kernel
Subject	Re: [PATCH] Improve Atheros ethernet driver not to do order 4 GFP_ATOMIC allocation
Date	Thu, 03 Dec 2015 08:50:01 +0100
Message-ID	<qBwOl-1XG-9@gated-at.bofh.it> (permalink)
References	<qzmzL-lM-1@gated-at.bofh.it> <qzP8K-1HY-11@gated-at.bofh.it> <qAwGK-4aw-15@gated-at.bofh.it> <qAZSq-622-19@gated-at.bofh.it> <qBwOl-1XG-11@gated-at.bofh.it>
X-Original-To	Chris Snook <chris.snook@gmail.com>
MIME-Version	1.0
Content-Type	text/plain; charset=utf-8
Content-Disposition	inline
Content-Transfer-Encoding	8bit
User-Agent	Mutt/1.5.23 (2014-03-12)
Sender	robomod@news.nic.it
List-ID	<linux-kernel.vger.kernel.org>
X-Mailing-List	linux-kernel@vger.kernel.org
Approved	robomod@news.nic.it
Lines	47
Organization	linux.* mail to news gateway
X-Original-Cc	David Miller <davem@davemloft.net>, 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
X-Original-Date	Thu, 3 Dec 2015 08:49:02 +0100
X-Original-Message-ID	<20151203074902.GB4139@amd>
X-Original-References	<20151127082010.GA2500@dhcp22.suse.cz> <20151128145113.GB4135@amd> <20151130132129.GB21950@dhcp22.suse.cz> <20151201.153517.224543138214404348.davem@davemloft.net> <CAMXMK6u1vQ772SGv-J3cKvOmS6QRAjjQLYiSiWO2+T=HRTiK1A@mail.gmail.com>
X-Original-Sender	linux-kernel-owner@vger.kernel.org
Xref	csiph.com linux.kernel:1282761

Show key headers only | View raw

On Wed 2015-12-02 22:43:31, Chris Snook wrote:
> On Tue, Dec 1, 2015 at 12:35 PM David Miller <davem@davemloft.net> wrote:
> 
> > From: Michal Hocko <mhocko@kernel.org>
> > 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
--
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/

Thread

Re: [PATCH] Improve Atheros ethernet driver not to do order 4  GFP_ATOMIC allocation David Miller <davem@davemloft.net> - 2015-12-01 21:40 +0100
  Re: [PATCH] Improve Atheros ethernet driver not to do order 4  GFP_ATOMIC allocation Pavel Machek <pavel@ucw.cz> - 2015-12-03 08:50 +0100
  Re: [PATCH] Improve Atheros ethernet driver not to do order 4  GFP_ATOMIC allocation Michal Hocko <mhocko@kernel.org> - 2015-12-03 09:20 +0100

csiph-web