From owner-freebsd-fs@freebsd.org Wed Feb 14 18:18:53 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 7BD57F1483A for ; Wed, 14 Feb 2018 18:18:53 +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 191B686267 for ; Wed, 14 Feb 2018 18:18:53 +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 6897316361 for ; Wed, 14 Feb 2018 18:18:52 +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 w1EIIqc3024552 for ; Wed, 14 Feb 2018 18:18:52 GMT (envelope-from bugzilla-noreply@freebsd.org) Received: (from www@localhost) by kenobi.freebsd.org (8.15.2/8.15.2/Submit) id w1EIIqCo024551 for freebsd-fs@FreeBSD.org; Wed, 14 Feb 2018 18:18:52 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 18:18:50 +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: cem@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: cc short_desc 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 18:18:53 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D209571 Conrad Meyer changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |cem@freebsd.org Summary|ZFS and NVMe performing |NVMe performing poorly. |poorly. TRIM requests stall |TRIM requests stall I/O |I/O activity |activity --- Comment #6 from Conrad Meyer --- I see the exact same problem with TRIM, Samsung 960 EVO, and UFS. Part of the problem is consumer controller (960 EVO) doing a bad job with T= RIM. Part of the problem is nvd does not coalesces TRIMs. Part of the problem is cam_iosched separates out and prioritizes TRIM over all other IO; see cam_iosched_next_bio(). (Separating out is useful for coalescing, but we d= on't actually coalesce yet.) I observed iostat showing non-zero queue depths and long IO latencies with = TRIM enabled (960 EVO). With TRIM disabled, qdepth was at most ever 1 and IO latency fell drastically under the same workload. --=20 You are receiving this mail because: You are the assignee for the bug.=