From owner-freebsd-bugs@freebsd.org Fri Sep 1 10:09:31 2017 Return-Path: Delivered-To: freebsd-bugs@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 0D8F1E0324C for ; Fri, 1 Sep 2017 10:09:31 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2001:1900:2254:206a::16:76]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id F00C86B392 for ; Fri, 1 Sep 2017 10:09:30 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from bugs.freebsd.org ([127.0.1.118]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id v81A9UZ7039706 for ; Fri, 1 Sep 2017 10:09:30 GMT (envelope-from bugzilla-noreply@freebsd.org) From: bugzilla-noreply@freebsd.org To: freebsd-bugs@FreeBSD.org Subject: [Bug 221973] cam iosched: BIO_ZONE commands probably shouldn't use the read queue Date: Fri, 01 Sep 2017 10:09:30 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: new X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: kern X-Bugzilla-Version: CURRENT X-Bugzilla-Keywords: patch X-Bugzilla-Severity: Affects Some People X-Bugzilla-Who: fk@fabiankeil.de X-Bugzilla-Status: New X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: freebsd-bugs@FreeBSD.org X-Bugzilla-Flags: mfc-stable11? X-Bugzilla-Changed-Fields: bug_id short_desc product version rep_platform op_sys bug_status keywords bug_severity priority component assigned_to reporter flagtypes.name attachments.created Message-ID: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 01 Sep 2017 10:09:31 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D221973 Bug ID: 221973 Summary: cam iosched: BIO_ZONE commands probably shouldn't use the read queue Product: Base System Version: CURRENT Hardware: Any OS: Any Status: New Keywords: patch Severity: Affects Some People Priority: --- Component: kern Assignee: freebsd-bugs@FreeBSD.org Reporter: fk@fabiankeil.de Flags: mfc-stable11? Created attachment 185970 --> https://bugs.freebsd.org/bugzilla/attachment.cgi?id=3D185970&action= =3Dedit cam iosched: Use the write queue for BIO_ZONE commands The attached patch lets iosched put BIO_ZONE commands on the write queue so they can't get executed ahead of writes that were sent after them. I'm not completely sure but believe that this is less likely to cause probl= ems than putting them one the read queue. As I currently don't use SMR drives the patch hasn't been properly tested. It prevents the kernel message: kernel: Found bio_cmd =3D 0x9 which cam_iosched_next_bio() emits when finding commands other than BIO_READ in the read queue, though. The fact that BIO_ZONE commands are sometimes sent to non-SMR drives may indicate another problem but I haven't looked into this yet. Obtained from: ElectroBSD --=20 You are receiving this mail because: You are the assignee for the bug.=