From owner-svn-src-all@FreeBSD.ORG Thu Oct 24 11:20:23 2013 Return-Path: Delivered-To: svn-src-all@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTP id 0588CE98; Thu, 24 Oct 2013 11:20:23 +0000 (UTC) (envelope-from slw@zxy.spb.ru) Received: from zxy.spb.ru (zxy.spb.ru [195.70.199.98]) by mx1.freebsd.org (Postfix) with ESMTP id B7A29251E; Thu, 24 Oct 2013 11:20:22 +0000 (UTC) Received: from slw by zxy.spb.ru with local (Exim 4.69 (FreeBSD)) (envelope-from ) id 1VZIzd-000GKj-23; Thu, 24 Oct 2013 15:22:21 +0400 Date: Thu, 24 Oct 2013 15:22:21 +0400 From: Slawa Olhovchenkov To: Steven Hartland Subject: Re: svn commit: r256956 - in head/sys: cam/ata cam/scsi cddl/contrib/opensolaris/uts/common/fs/zfs cddl/contrib/opensolaris/uts/common/fs/zfs/sys geom sys Message-ID: <20131024112221.GY63359@zxy.spb.ru> References: <201310230954.r9N9sxAZ011750@svn.freebsd.org> <20131024102118.GA59011@zxy.spb.ru> <062D17FCE7E44812812E249D864EF0DA@multiplay.co.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <062D17FCE7E44812812E249D864EF0DA@multiplay.co.uk> User-Agent: Mutt/1.5.21 (2010-09-15) X-SA-Exim-Connect-IP: X-SA-Exim-Mail-From: slw@zxy.spb.ru X-SA-Exim-Scanned: No (on zxy.spb.ru); SAEximRunCond expanded to false Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.14 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: Thu, 24 Oct 2013 11:20:23 -0000 On Thu, Oct 24, 2013 at 12:00:54PM +0100, Steven Hartland wrote: > Not familiar with that option, but having a quick look in src > it doesn't seem to be FS specific, seems to be handled by vfs. VFS set options include this (in high bits). This options next passed to FS code (.vop_read = zfs_freebsd_read), in FS(zfs) code options filtered: return (zfs_read(ap->a_vp, ap->a_uio, ioflags(ap->a_ioflag), ap->a_cred, NULL)); ioflags(int ioflags) { int flags = 0; if (ioflags & IO_APPEND) flags |= FAPPEND; if (ioflags & IO_NDELAY) flags |= FNONBLOCK; if (ioflags & IO_SYNC) flags |= (FSYNC | FDSYNC | FRSYNC); return (flags); } and we lost FRDAHEAD/ADVISE hints, IO_DIRECT, IO_INVAL and so. > Can anyone confirm or deny this? > > ----- Original Message ----- > From: "Slawa Olhovchenkov" > > > > On Wed, Oct 23, 2013 at 09:54:59AM +0000, Steven Hartland wrote: > > > >> Author: smh > >> Date: Wed Oct 23 09:54:58 2013 > >> New Revision: 256956 > >> URL: http://svnweb.freebsd.org/changeset/base/256956 > >> > >> Log: > >> Improve ZFS N-way mirror read performance by using load and locality > >> information. > > > > What about support F_READAHEAD in ZFS (with prefetch disabled by > > CPU-intensive)? > > > > ================================================ > This e.mail is private and confidential between Multiplay (UK) Ltd. and the person or entity to whom it is addressed. In the event of misdirection, the recipient is prohibited from using, copying, printing or otherwise disseminating it or any information contained in it. > > In the event of misdirection, illegible or incomplete transmission please telephone +44 845 868 1337 > or return the E.mail to postmaster@multiplay.co.uk. >