From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kara Subject: Re: [MMTests] dbench4 async on ext3 Date: Wed, 22 Aug 2012 00:00:38 +0200 Message-ID: <20120821220038.GA19171@quack.suse.cz> References: <20120620113252.GE4011@suse.de> <20120629111932.GA14154@suse.de> <20120723212146.GG9222@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org To: Mel Gorman Return-path: Content-Disposition: inline In-Reply-To: <20120723212146.GG9222@suse.de> Sender: owner-linux-mm@kvack.org List-Id: linux-fsdevel.vger.kernel.org On Mon 23-07-12 22:21:46, Mel Gorman wrote: > Configuration: global-dhp__io-dbench4-async-ext3 > Result: http://www.csn.ul.ie/~mel/postings/mmtests-20120424/global-dhp__io-dbench4-async-ext3 > Benchmarks: dbench4 > > Summary > ======= > > In general there was a massive drop in throughput after 3.0. Very broadly > speaking it looks like the Read operation got faster but at the cost of > a big regression in the Flush operation. Mel, I had a look into this and it's actually very likely only a configuration issue. In 3.1 ext3 started to default to enabled barriers (barrier=1 in mount options) which is a safer but slower choice. When I set barriers explicitely, I see no performance difference for dbench4 between 3.0 and 3.1. Honza -- Jan Kara SUSE Labs, CR -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org