From owner-svn-src-all@freebsd.org Mon Nov 20 22:27:35 2017 Return-Path: Delivered-To: svn-src-all@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 3268EDF7370; Mon, 20 Nov 2017 22:27:35 +0000 (UTC) (envelope-from asomers@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (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 F05B570446; Mon, 20 Nov 2017 22:27:34 +0000 (UTC) (envelope-from asomers@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id vAKMRY1Y001933; Mon, 20 Nov 2017 22:27:34 GMT (envelope-from asomers@FreeBSD.org) Received: (from asomers@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id vAKMRYvW001932; Mon, 20 Nov 2017 22:27:34 GMT (envelope-from asomers@FreeBSD.org) Message-Id: <201711202227.vAKMRYvW001932@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: asomers set sender to asomers@FreeBSD.org using -f From: Alan Somers Date: Mon, 20 Nov 2017 22:27:34 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r326036 - head/sys/cam/scsi X-SVN-Group: head X-SVN-Commit-Author: asomers X-SVN-Commit-Paths: head/sys/cam/scsi X-SVN-Commit-Revision: 326036 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.25 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 20 Nov 2017 22:27:35 -0000 Author: asomers Date: Mon Nov 20 22:27:33 2017 New Revision: 326036 URL: https://svnweb.freebsd.org/changeset/base/326036 Log: da(4): Short-circuit unnecessary BIO_FLUSH commands sys/cam/scsi/scsi_da.c Complete BIO_FLUSH commands immediately if the da(4) device hasn't been written to since the last flush. If we haven't written to the device, there is no reason to send a flush. Submitted by: gibbs Reviewed by: imp MFC after: 3 weeks Sponsored by: Spectra Logic Corp Differential Revision: https://reviews.freebsd.org/D13106 Modified: head/sys/cam/scsi/scsi_da.c Modified: head/sys/cam/scsi/scsi_da.c ============================================================================== --- head/sys/cam/scsi/scsi_da.c Mon Nov 20 22:18:24 2017 (r326035) +++ head/sys/cam/scsi/scsi_da.c Mon Nov 20 22:27:33 2017 (r326036) @@ -3038,6 +3038,18 @@ more: } case BIO_FLUSH: /* + * If we don't support sync cache, or the disk + * isn't dirty, FLUSH is a no-op. Use the + * allocated * CCB for the next bio if one is + * available. + */ + if ((softc->quirks & DA_Q_NO_SYNC_CACHE) != 0 || + (softc->flags & DA_FLAG_DIRTY) == 0) { + biodone(bp); + goto skipstate; + } + + /* * BIO_FLUSH doesn't currently communicate * range data, so we synchronize the cache * over the whole disk. We also force @@ -3052,6 +3064,15 @@ more: /*lb_count*/0, SSD_FULL_SIZE, da_default_timeout*1000); + /* + * Clear the dirty flag before sending the command. + * Either this sync cache will be successful, or it + * will fail after a retry. If it fails, it is + * unlikely to be successful if retried later, so + * we'll save ourselves time by just marking the + * device clean. + */ + softc->flags &= ~DA_FLAG_DIRTY; break; case BIO_ZONE: { int error, queue_ccb;