Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751429AbWACOKS (ORCPT ); Tue, 3 Jan 2006 09:10:18 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751430AbWACOKR (ORCPT ); Tue, 3 Jan 2006 09:10:17 -0500 Received: from e2.ny.us.ibm.com ([32.97.182.142]:5573 "EHLO e2.ny.us.ibm.com") by vger.kernel.org with ESMTP id S1751429AbWACOKQ (ORCPT ); Tue, 3 Jan 2006 09:10:16 -0500 Date: Tue, 3 Jan 2006 19:41:01 +0530 From: Dipankar Sarma To: David Lang 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 Message-ID: <20060103141101.GC5075@in.ibm.com> Reply-To: dipankar@in.ibm.com References: <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 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.10i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1123 Lines: 25 On Tue, Jan 03, 2006 at 05:28:15AM -0800, David Lang wrote: > 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. Yes, I think it would make sense to try something like that. See Paul's earlier mail in this thread for an example code snippet. Thanks Dipankar - 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/