Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932362AbWACNaw (ORCPT ); Tue, 3 Jan 2006 08:30:52 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932373AbWACNar (ORCPT ); Tue, 3 Jan 2006 08:30:47 -0500 Received: from warden-p.diginsite.com ([208.29.163.248]:38399 "HELO warden.diginsite.com") by vger.kernel.org with SMTP id S932367AbWACNaW (ORCPT ); Tue, 3 Jan 2006 08:30:22 -0500 Date: Tue, 3 Jan 2006 05:28:15 -0800 (PST) From: David Lang X-X-Sender: dlang@dlang.diginsite.com To: Dipankar Sarma cc: Linus Torvalds , Lee Revell , paulmck@us.ibm.com, Ingo Molnar , Dave Jones , Hugh Dickins , linux-kernel , Eric Dumazet , vatsa@in.ibm.com Subject: Re: [patch] latency tracer, 2.6.15-rc7 In-Reply-To: <20060103111211.GA5075@in.ibm.com> Message-ID: References: <1135990270.31111.46.camel@mindpipe> <1135991732.31111.57.camel@mindpipe> <1136001615.3050.5.camel@mindpipe> <20051231042902.GA3428@us.ibm.com> <1136004855.3050.8.camel@mindpipe> <20051231201426.GD5124@us.ibm.com> <1136094372.7005.19.camel@mindpipe> <20060103111211.GA5075@in.ibm.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1146 Lines: 25 On Tue, 3 Jan 2006, Dipankar Sarma wrote: > I do agree that the two layers of batching really makes things > subtle. I think the best we can do is to figure out some way of > automatic throttling in RCU and forced quiescent state under extreme > conditions. That way we will have less dependency on softirq > throttling. would it make sense to have the RCU subsystems with a threshold so that when more then X items are outstanding they trigger a premption of all other CPU's ASAP (forceing the scheduling break needed to make progress on clearing RCU)? This wouldn't work in all cases, but it could significantly reduce the problem situations. David Lang -- There are two ways of constructing a software design. One way is to make it so simple that there are obviously no deficiencies. And the other way is to make it so complicated that there are no obvious deficiencies. -- C.A.R. Hoare - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/