From mboxrd@z Thu Jan 1 00:00:00 1970 From: Doug Ledford Subject: Re: Any progress on horrible IPoIB perf with kernel 4.5+? Date: Tue, 12 Jul 2016 10:25:25 -0400 Message-ID: <447685d8-1380-2a57-dc83-88b3871fee3f@redhat.com> References: Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="fExPd6Mra78HM2owwwMskkplf5IVEVf8f" Return-path: In-Reply-To: Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Roland Dreier , "linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" Cc: Konstantin Khlebnikov List-Id: linux-rdma@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --fExPd6Mra78HM2owwwMskkplf5IVEVf8f Content-Type: multipart/mixed; boundary="8rfjGCW0BIripubedboMFc7W59fi80tnr" From: Doug Ledford To: Roland Dreier , "linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" Cc: Konstantin Khlebnikov Message-ID: <447685d8-1380-2a57-dc83-88b3871fee3f-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> Subject: Re: Any progress on horrible IPoIB perf with kernel 4.5+? References: In-Reply-To: --8rfjGCW0BIripubedboMFc7W59fi80tnr Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On 7/6/2016 1:09 PM, 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 l= ink > went from ~200 MB/sec down to below 1 MB/sec. I confirmed that > reverting that change did fix my performance. >=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? >=20 > Thanks, > Roland >=20 I *just* came back from PTO. I'm still working through my email (where I saw your writeup of this issue). I didn't get very far with the issue back in May, but that's because I didn't have a lot of the background information you supplied in the other thread and didn't have the time to dig it out on my own. I could probably make some progress now. --=20 Doug Ledford GPG Key ID: 0E572FDD --8rfjGCW0BIripubedboMFc7W59fi80tnr-- --fExPd6Mra78HM2owwwMskkplf5IVEVf8f Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQIcBAEBCAAGBQJXhP3VAAoJELgmozMOVy/dBSoP/A6NY8bhE7sjsMLDZgnmZbWf FW97dUE9mx+U1K1QVDdiEbGyLDUrk31iKwG5fimR+0aXqoqxcHE9ha4Fal1k6J5o WvVX8e35uykeR6h8oyQ4C9Cum/KWKq1+3hXr34w1xsALmkL0QMfPt8eJFBPvnAD2 a/D7sx+sq+cWu+deDEWvGIWHlaCKYlofl01JhgCTswGeA7DdCKbuDoBsheWCFPjc ZK9JwFCl/LncW5DoBrvJMynTElfA9yyCesAyQj+h0NDv6zF/lCulC+/hScy2vesS XTHekIyOQJyf4bnyInF7oSEC0pHLCFp/l634WNPT6KZgFChlYLUytYrteQgyRcwC /GgZgs5hJtl3ici2ZVeF3K+IAdYNxmx4dWTYUgySBojwWOEYd9IzgSX72zqOsAKp HM0O1iQgbOusI7ZbJJ5VclTdxRnhUtYCI799Cl6W0QjSl4FnsYAHIxbzvG1OkTj5 q9UmWOkXOScWlS4mG04MEQh+hB+Bk66HNV5hBy6n4tmRRgg690Gsy7RHO9eh6lrt aB4LWELLavn34ZEn+WYTaQcH534hr1VrSLyT+lIf1lk05ODOJ+Dow4+9Ip9ByX4c WQMkPyYtnmA9IAvAShSX0cUGaC+sTpvhrEKaPqf0MKbTK4mqLhIOz5c3E+GOIkFj qZkLHINmV+RJNSNsHMiM =oaEv -----END PGP SIGNATURE----- --fExPd6Mra78HM2owwwMskkplf5IVEVf8f-- -- 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