From mboxrd@z Thu Jan 1 00:00:00 1970 From: Leon Romanovsky Subject: Re: [PATCH] IB/mlx4: Allocation of CQ resize structure doesn't need to be atomic Date: Sun, 31 Jul 2016 09:42:45 +0300 Message-ID: <20160731064245.GX4628@leon.nu> References: <1469768323-8093-1-git-send-email-roland@kernel.org> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="1IWgL8yD8uKyf/Tu" Return-path: Content-Disposition: inline In-Reply-To: <1469768323-8093-1-git-send-email-roland-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Roland Dreier Cc: Yishai Hadas , Doug Ledford , linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-rdma@vger.kernel.org --1IWgL8yD8uKyf/Tu Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Jul 28, 2016 at 09:58:43PM -0700, Roland Dreier wrote: > From: Roland Dreier >=20 > We allocate a small tracking structure as part of mlx4_ib_resize_cq(). > However, we don't need to use GFP_ATOMIC -- immediately after the > allocation, we call mlx4_cq_resize(), which allocates a command > mailbox with GFP_KERNEL and then sleeps on a firmware command, so we > better not be in an atomic context. >=20 > This actually has a real impact, because when this GFP_ATOMIC > allocation fails (and GFP_ATOMIC does fail in practice) then a > userspace consumer resizing a CQ will get a spurious failure that we > can easily avoid. >=20 > Signed-off-by: Roland Dreier Thanks, Reviewed-by: Leon Romanovsky --1IWgL8yD8uKyf/Tu Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJXnZ3lAAoJEORje4g2clinpsEP/3D9Xn+use53YJPSK05XfBgs 6ofXhaO284qK27qihdEWNbjDBbqw9VP8apd2wFb6s20KeZAPRtOAV96P4zeziUA6 0EbgmsBbf8/1IG2g4r2mxkL36p5Ji0p+d4MVht75SD1nZg6rfT7TWsM+eKsvqmRC kHbRtyokIVOvkQzqAOcwCcRzb3TS/N400LGRhTXLe4aLJ+9qKqshn0wkeR4UNze0 SkgIvVVbcsVC1TnXjvHXajOW3G+qyEPPPqCu/DxUoIiHtCo35TznHoCfC7S3B5zf SrL47L7tCElcObNHGGXWqlPjgN+lzDKh8E6Z/GspV9rkzmM6JUM2ntNbbJK32Zom 5S5FM1tcYOhBtiO9WxqjElW5yBbsVX8t+KpXoH23eGv3/5S8gBwKl0ubNV6jLeSw dmxyv+jSzoO6KitTEujlCl5OX5cQ5MGCRfltur//r1AEUlWYdXQetP/BZzhZlt17 QORmzai0YS1iIoYVsZfKNJyJCrFBAmViQu6mZvWELoMl0ze9k95AhRiBV1fzfoEW c2Z2Mo2c/JXtP7al14v/GiFE/aYHcNnLIUqJlnx1niOy38LvkuJsH4YwzSRLoWFJ Eu06BAUxEr/2moFGNQ7ctlGMFP9kFWBCuOFpf2CUhoGZYrO7ubqdXJkVIoMxUk0G UfvfuZPXFTXj8OToDrzk =djYK -----END PGP SIGNATURE----- --1IWgL8yD8uKyf/Tu-- -- 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