From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?iso-8859-1?Q?Bj=F6rn?= JACKE Subject: Re: [PATCH] cifs: lower default wsize when unix extensions are not used Date: Wed, 23 Nov 2011 19:34:05 +0100 Message-ID: References: <1320863843-29406-1-git-send-email-jlayton@redhat.com> <20111109134140.2105ed9e@corrin.poochiereds.net> <20111109160408.44947815@corrin.poochiereds.net> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Steve French , linux-cifs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, phireph0x-/E1597aS9LQAvxtiuMwx3w@public.gmane.org, piastry-7qunaywFIewox3rIn2DAYQ@public.gmane.org To: Jeff Layton Return-path: Content-Disposition: inline In-Reply-To: <20111109160408.44947815-4QP7MXygkU+dMjc06nkz3ljfA9RmPOcC@public.gmane.org> Sender: linux-cifs-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: On 2011-11-09 at 16:04 -0500 Jeff Layton sent off: > On Wed, 9 Nov 2011 14:55:36 -0600 > Steve French wrote: >=20 > > How much of a performance hit does this make? I would expect that > > dropping the writesize by more than 50% to most non-Samba servers t= o > > work around a bug in Solaris seems extreme. If this hurts our > > performance measurably, it may be more pragmatic to limit the wsize > > change to a subset of these (e.g. based on server type) - seems mor= e > > fair to not punish other servers for a Solaris bug. > >=20 >=20 > I'm not sure how big a hit it will be, but it won't be 0. As always, = it > depends on workload. The problem is, I'm not sure we can reliably > detect when the server can't handle larger writes like this. I've seen a performance drop from 60MB/s to 50MB/s on a 1GB switched ne= twork when unix extensions were disabled just because the rsize was limited f= rom 128k to 64k. That was tested with Darwin's smbfs but the dropdown in perform= ance of cifs vfs will be similar. If this can be seen as a server bug I'd also = like to see Oracle fix their server and keep cifs vfs be able to use 128k. Bj=F6rn