From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bill Davidsen Subject: Re: Odd (slow) RAID performance Date: Sat, 09 Dec 2006 15:20:18 -0500 Message-ID: <457B1A82.6070105@tmr.com> References: <456F4872.2090900@tmr.com> <20061201092211.4ACDB12EDE@bluewhale.planbit.co.uk> <45710EDC.9050805@tmr.com> <17784.65477.993729.508985@cse.unsw.edu.au> <17785.5135.749830.180388@cse.unsw.edu.au> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <17785.5135.749830.180388@cse.unsw.edu.au> Sender: linux-raid-owner@vger.kernel.org To: Neil Brown Cc: Dan Williams , Roger Lucas , linux-raid@vger.kernel.org List-Id: linux-raid.ids Neil Brown wrote: > On Friday December 8, neilb@suse.de wrote: > >> I have measured very slow write throughput for raid5 as well, though >> 2.6.18 does seem to have the same problem. I'll double check and do a >> git bisect and see what I can come up with. >> > > Correction... it isn't 2.6.18 that fixes the problem. It is compiling > without LOCKDEP or PROVE_LOCKING. I remove those and suddenly a > 3 drive raid5 is faster than a single drive rather than much slower. > > Bill: Do you have LOCKDEP or PROVE_LOCKING enabled in your .config ?? > I have to check tomorrow, I'm using the Fedora kernel (as noted in the first post on this) rather than one I built, just so others could verify my results as several have been kind enough to do. Have to run, but I will check tomorrow or Monday morning early at the latest. -- bill davidsen CTO TMR Associates, Inc Doing interesting things with small computers since 1979