From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx186.postini.com [74.125.245.186]) by kanga.kvack.org (Postfix) with SMTP id 54DF56B0083 for ; Tue, 15 May 2012 09:16:37 -0400 (EDT) Date: Tue, 15 May 2012 21:15:33 +0800 From: Fengguang Wu Subject: Re: [PATCH 0/2 v2] Flexible proportions for BDIs Message-ID: <20120515131533.GA4753@localhost> References: <1336084760-19534-1-git-send-email-jack@suse.cz> <20120507144344.GA13983@localhost> <20120509113720.GC5092@quack.suse.cz> <20120510073123.GA7523@localhost> <20120511145114.GA18227@localhost> <20120513032952.GA8099@localhost> <20120514212803.GT5353@quack.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120514212803.GT5353@quack.suse.cz> Sender: owner-linux-mm@kvack.org List-ID: To: Jan Kara Cc: linux-mm@kvack.org, peterz@infradead.org Hi Jan, > > The observations for this box are > > > > - the 3s and 8s periods result in roughly the same adaption speed > > > > - the patch makes a really *big* difference in systems with big > > memory:bandwidth ratio. It's sweet! In comparison, the vanilla > > kernel adapts to new write bandwidth so much slower. > Yes, in this configuration the benefit of the new algorithm can be clearly > seen. Together with the results of previous test I'd say 3s period is the > best candidate. Agreed. I'm fine with the fixed 3s period. > Just I was thinking whether the period shouldn't be somehow set > automatically because I'm not convinced 3s will be right for everybody... > Maybe something based on how big fluctuations in completion rate we > observe. But it would be tricky given the load itself changes as well. So > for now we'll have to live with a hardwired period I guess. Yeah, simple fixed periods should be good enough. > Thanks for the tests Fengguang! So is anybody against merging this? No problem for me, when Peter's concern is addressed. Thanks! Fengguang -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org