From owner-freebsd-fs@FreeBSD.ORG Fri Aug 8 22:05:59 2008 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id EF0451065670; Fri, 8 Aug 2008 22:05:59 +0000 (UTC) (envelope-from peter.schuller@infidyne.com) Received: from smtp.infidyne.com (ds9.infidyne.com [88.80.6.206]) by mx1.freebsd.org (Postfix) with ESMTP id ABE058FC17; Fri, 8 Aug 2008 22:05:59 +0000 (UTC) (envelope-from peter.schuller@infidyne.com) Received: from c-a916e555.03-51-73746f3.cust.bredbandsbolaget.se (c-a916e555.03-51-73746f3.cust.bredbandsbolaget.se [85.229.22.169]) by smtp.infidyne.com (Postfix) with ESMTPSA id 07A5D8472D; Sat, 9 Aug 2008 00:05:58 +0200 (CEST) From: Peter Schuller To: Pawel Jakub Dawidek Date: Sat, 9 Aug 2008 00:07:15 +0200 User-Agent: KMail/1.9.7 References: <200807262005.54235.peter.schuller@infidyne.com> <200807272026.54907.peter.schuller@infidyne.com> <20080806185909.GC2580@garage.freebsd.pl> In-Reply-To: <20080806185909.GC2580@garage.freebsd.pl> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart46921207.vcrJ7sQpCh"; protocol="application/pgp-signature"; micalg=pgp-sha1 Content-Transfer-Encoding: 7bit Message-Id: <200808090007.25865.peter.schuller@infidyne.com> Cc: freebsd-fs@freebsd.org Subject: Re: Asynchronous writing to zvols (ZFS) X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 08 Aug 2008 22:06:00 -0000 --nextPart46921207.vcrJ7sQpCh Content-Type: text/plain; charset="iso-8859-15" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline [zvol write performance less than file-on-zfs] > Not sure why's that, I spent no time on optimizing ZVOL yet, sorry. Absolutely, I was not complaining! I just felt it was worth mentioning. It = was=20 not meant to be negative criticism. > With the patch above we synchoronize in-memory transactions every 5 > seconds or when queue is full or when we receive BIO_FLUSH.=20 That was my understanding. Sorry, I probably wasn't being clear. I thought= =20 your original comment ("The problem is that we don't between async and sync= =20 I/O request on GEOM level") implied that there was some reason one could no= t=20 trust bio_cmd to be preserved correctly (somehow being downgraded from=20 BIO_FLUSH before it reaches the zvol class). Because if this was the case = it=20 would make perfect sense under the circumstances to treat all writes as=20 flushes, in order to achieve correct semantics for *actual* flushes. So my question was meant to confirm that this was not the case, because if = it=20 were, the patch would mean that *actual* flushes would not get treated as=20 such. Thanks, =2D-=20 / Peter Schuller PGP userID: 0xE9758B7D or 'Peter Schuller ' Key retrieval: Send an E-Mail to getpgpkey@scode.org E-Mail: peter.schuller@infidyne.com Web: http://www.scode.org --nextPart46921207.vcrJ7sQpCh Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part. -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (FreeBSD) iEYEABECAAYFAkicw50ACgkQDNor2+l1i30KQQCg2rGWUR8BACnZ9Yu7x6VpSWhG zdIAoKMXIoljbq6lhcaE5ChgUOA3CpVF =HrQV -----END PGP SIGNATURE----- --nextPart46921207.vcrJ7sQpCh--