From owner-freebsd-fs@freebsd.org Wed Feb 14 23:34:43 2018 Return-Path: Delivered-To: freebsd-fs@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id AB43EF064C2 for ; Wed, 14 Feb 2018 23:34:43 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mxrelay.ysv.freebsd.org (mxrelay.ysv.freebsd.org [IPv6:2001:1900:2254:206a::19:3]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "mxrelay.ysv.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 3D092734B0 for ; Wed, 14 Feb 2018 23:34:43 +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 mxrelay.ysv.freebsd.org (Postfix) with ESMTPS id 6F3E119043 for ; Wed, 14 Feb 2018 23:34:42 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org ([127.0.1.118]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id w1ENYgvb037970 for ; Wed, 14 Feb 2018 23:34:42 GMT (envelope-from bugzilla-noreply@freebsd.org) Received: (from www@localhost) by kenobi.freebsd.org (8.15.2/8.15.2/Submit) id w1ENYgQv037969 for freebsd-fs@FreeBSD.org; Wed, 14 Feb 2018 23:34:42 GMT (envelope-from bugzilla-noreply@freebsd.org) X-Authentication-Warning: kenobi.freebsd.org: www set sender to bugzilla-noreply@freebsd.org using -f From: bugzilla-noreply@freebsd.org To: freebsd-fs@FreeBSD.org Subject: [Bug 209571] NVMe performing poorly. TRIM requests stall I/O activity Date: Wed, 14 Feb 2018 23:34:42 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: kern X-Bugzilla-Version: 10.3-RELEASE X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Many People X-Bugzilla-Who: imp@FreeBSD.org X-Bugzilla-Status: New X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: freebsd-fs@FreeBSD.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: 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-fs@freebsd.org X-Mailman-Version: 2.1.25 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 14 Feb 2018 23:34:43 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D209571 --- Comment #8 from Warner Losh --- Only if you are using nda, which most people aren't. It doesn't exist in 10= or 11 (well, until last week). It's not turned on by default in 12. So talking about cam_ioschded and nvd in the same breath misunderstands the problem. nvd doesn't collapse trims and that's the problem there. It doesn't use CAM at all so no tweaks to cam_iosched is going to help because it's completely unused. nda, on the other hand, has the collapsing trim issue and the priority inversion issue cem points out. I've been tweaking the code to reduce trim priority as well as collapse trims, but that won't help nvd. I = have no plans on doing anything with nvd. So if you are using nvd, the whole problem is lack of trim collapsing. If y= ou are using nda, that problem is compounded by the I/O scheduler. I should ha= ve a fix for nda by the end of next week. --=20 You are receiving this mail because: You are the assignee for the bug.=