From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yuval Shaia Subject: Re: Any progress on horrible IPoIB perf with kernel 4.5+? Date: Wed, 6 Jul 2016 20:46:04 +0300 Message-ID: <20160706174603.GF4299@yuval-lap.uk.oracle.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Roland Dreier , Haakon Bugge Cc: "linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Doug Ledford , Konstantin Khlebnikov List-Id: linux-rdma@vger.kernel.org On Wed, Jul 06, 2016 at 10:09:51AM -0700, Roland Dreier wrote: > Hi, >=20 > https://bugzilla.kernel.org/show_bug.cgi?id=3D111921 describes a > performance regression introduced by commit 9207f9d45b0a ("net: > preserve IP control block during GSO segmentation"). I've recently > run into this when updating my system, since that commit hit stable > kernel 4.4.y =E2=80=94 in my case I noticed because scp over an IPoIB= link > went from ~200 MB/sec down to below 1 MB/sec. I confirmed that > reverting that change did fix my performance. Same for us. >=20 > Obviously just reverting that commit isn't the right answer, since I > believe the patch description that says the commit fixes a crash. > However before I start working on this myself, I want to make sure I'= m > not duplicating anyone else's work. Doug, you mentioned having time > to work on it back in May =E2=80=94 did you figure anything out? Or = is anyone > else investigating this? Adding Haakon which as far as i recall has some insights. >=20 > Thanks, > Roland > -- > To unsubscribe from this list: send the line "unsubscribe linux-rdma"= in > the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" i= n the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html