From mboxrd@z Thu Jan 1 00:00:00 1970 From: Doug Ledford Subject: Re: [PATCH] IB/mlx5: Expose correct max_sge_rd limit Date: Thu, 28 Apr 2016 10:53:14 -0400 Message-ID: <572223DA.7030805@redhat.com> References: <1459440205-25208-1-git-send-email-sagig@grimberg.me> <20160401000426.GF2670@leon.nu> <570606B4.5040402@grimberg.me> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="PCGETE7X1QtowVqX7EWrQnqpVHV6uJDkU" Return-path: In-Reply-To: <570606B4.5040402-NQWnxTmZq1alnMjI0IkVqw@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Sagi Grimberg Cc: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Matan Barak , Leon Romanovsky List-Id: linux-rdma@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --PCGETE7X1QtowVqX7EWrQnqpVHV6uJDkU Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable On 04/07/2016 03:05 AM, Sagi Grimberg wrote: >=20 >=20 > On 01/04/16 03:04, Leon Romanovsky wrote: >> On Thu, Mar 31, 2016 at 07:03:25PM +0300, Sagi Grimberg wrote: >>> mlx5 devices (Connect-IB, ConnectX-4, ConnectX-4-LX) has a limitation= >>> where rdma read work queue entries cannot exceed 512 bytes. >>> A rdma_read wqe needs to fit in 512 bytes: >>> - wqe control segment (16 bytes) >>> - rdma segment (16 bytes) >>> - scatter elements (16 bytes each) >>> >>> So max_sge_rd should be: (512 - 16 - 16) / 16 =3D 30. >>> >>> Reported-by: Christoph Hellwig >>> Tested-by: Christoph Hellwig >>> Signed-off-by: Sagi Grimberg >> >> Thanks Sagi, >> >> Excellent catch, the same as in commit: a5e4ba334e2 >> ("mlx4: Expose correct max_sge_rd limit") >> >> Signed-off-by: Leon Romanovsky >=20 > Doug, this is stable material, can we get it to 4.6-rc > and place a stable tag on it? >=20 > Thanks, > Sagi. Done, thanks. --=20 Doug Ledford GPG KeyID: 0E572FDD --PCGETE7X1QtowVqX7EWrQnqpVHV6uJDkU 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/ iQIcBAEBCAAGBQJXIiPaAAoJELgmozMOVy/dprIP/jHduLmPbrDJTHwHQiJmZ/4d +apUurwwql/JyPHpFeXm5zxN4iMt5/7b1BkvQpXxLmM5RWMa1KoHAovlZWws22On i9UwExxwLkTz88xJzGfdJa4GhYDHSSBH6go7VxVvtkCgMdPC7Z2sqQO3TzGrhByO g4pWXDWwuQUtZQy50JEbMS/Qq9kKOHiGc/iFgO7L8JLZizFoFZc4HTkNJLhWoFq1 47w33cGASVaasrJc5tj4I5t1pMOgsdgxZ1PQDGspIXeK29oGzPNG8PhQsLOGx/Cy A8uhHaFm1Mc0EpZIKnpDuREqNwZ4HNmoeNNSLgftietBvWwst9OlsWlFMgbYrqqw gUuoVadIe1/fRJdg2jUSEjEekqG3tWYHJRZqPEOY7UpkQ+AKoFt+gQ9PLMwgciqv qtuc1TVsmd94mSaMIA0T9ZlsBdJQAOtEAF3MOO05atMRQLzkfoVJCdYrJS9YWB9p sr0BGJOTfrx8ki0BxK8u09ur80hkx90wmRR9t3W+5TtU7jTVxIChzjxpCN3RvFCM JFpWJkskU/wN6v/mldSWGGUeFvZ95v6V1y0slCiHPb5ERhEmzqvmJxQA9fe95Rz/ MemTZT2P6CfuS/6HwX5LTbjIc4n+MKuE/BmWKvVhYxKsGxzOYwHz1EpppeIJlY8n M3ULesYNmrmAYnWEY7Hh =pOWR -----END PGP SIGNATURE----- --PCGETE7X1QtowVqX7EWrQnqpVHV6uJDkU-- -- 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