Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934485AbcLBKmq (ORCPT ); Fri, 2 Dec 2016 05:42:46 -0500 Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:40103 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934445AbcLBKmm (ORCPT ); Fri, 2 Dec 2016 05:42:42 -0500 Date: Fri, 2 Dec 2016 11:42:38 +0100 From: Pavel Machek To: Giuseppe CAVALLARO Cc: David Miller , alexandre.torgue@st.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: stmmac: turn coalescing / NAPI off in stmmac Message-ID: <20161202104238.GA31172@amd> References: <20161124085506.GA25007@amd> <20161124.110416.198867271899443489.davem@davemloft.net> <20161130114431.GB14296@amd> <20161201.152303.425589678238707778.davem@davemloft.net> <20161201224827.GA26301@amd> <2ceae6dc-3a48-3212-c634-cc6f1f0b363f@st.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="PNTmBPCT7hxwcZjr" Content-Disposition: inline In-Reply-To: <2ceae6dc-3a48-3212-c634-cc6f1f0b363f@st.com> 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 Content-Length: 2780 Lines: 84 --PNTmBPCT7hxwcZjr Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi! > >Anyway... since you asked. I belive I have way to disable NAPI / tx > >coalescing in the driver. Unfortunately, locking is missing on the rx > >path, and needs to be extended to _irqsave variant on tx path. >=20 > I have just replied to a previous thread about that... Yeah, please reply to David's mail where he describes why it can't work. > >So patch currently looks like this (hand edited, can't be > >applied, got it working few hours ago). Does it look acceptable? > > > >I'd prefer this to go after the patch that pulls common code to single > >place, so that single place needs to be patched. Plus I guess I should > >add ifdefs, so that more advanced NAPI / tx coalescing code can be > >reactivated when it is fixed. Trivial fixes can go on top. Does that > >sound like a plan? >=20 > Hmm, what I find strange is that, just this code is running since a > long time on several platforms and Chip versions. No raise condition > have been found or lock protection problems (also proving look > mechanisms). Well, it works better for me when I disable CONFIG_SMP. It is normal that locking problems are hard to reproduce :-(. > Pavel, I ask you sorry if I missed some problems so, if you can > (as D. Miller asked) to send us a cover letter + all patches > I will try to reply soon. I can do also some tests if you ask > me that! I could run on 3.x and 4.x but I cannot promise you > benchmarks. Actually... I have questions here. David normally pulls from you (can I have a address of your git tree?). Could you apply these to your git? [PATCH] stmmac ethernet: unify locking [PATCH] stmmac: simplify flag assignment [PATCH] stmmac: cleanup documenation, make it match reality They are rather trivial and independend, I'm not sure what cover letter would say, besides "simple fixes". Then I can re-do the reset on top of that... > >Which tree do you want patches against? > > > >https://git.kernel.org/cgit/linux/kernel/git/davem/net-next.git/ ? >=20 > I think that bug fixing should be on top of net.git but I let Miller > to decide. Hmm. It is "only" a performance problem (40msec delays).. I guess -next is better target. Best regards, Pavel --=20 (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blo= g.html --PNTmBPCT7hxwcZjr Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEARECAAYFAlhBUB4ACgkQMOfwapXb+vIyUACdG+ClPNPRNSYutf9Mh5cJLl8A EwoAniX6EFkyByRMkJmLHyW4uJo/uc5q =WhY6 -----END PGP SIGNATURE----- --PNTmBPCT7hxwcZjr--