From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Paul E. McKenney" Subject: Re: [PATCH RT] convert RCU Preempt tasklet into softirq. Date: Fri, 8 Jun 2007 08:00:10 -0700 Message-ID: <20070608150010.GA24579@linux.vnet.ibm.com> References: <1181180051.18444.31.camel@localhost.localdomain> <20070607041411.GB1783@linux.vnet.ibm.com> <1181226138.18444.54.camel@localhost.localdomain> <20070607161754.GA11941@linux.vnet.ibm.com> <1181240819.10408.14.camel@localhost.localdomain> <1181242307.10408.17.camel@localhost.localdomain> <1181247369.10408.20.camel@localhost.localdomain> <20070608041651.GA19912@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: john stultz , Ingo Molnar , Thomas Gleixner , Oleg Nesterov , LKML , Dipankar Sarma , RT To: Steven Rostedt Return-path: Received: from e3.ny.us.ibm.com ([32.97.182.143]:33274 "EHLO e3.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755968AbXFHPAO (ORCPT ); Fri, 8 Jun 2007 11:00:14 -0400 Content-Disposition: inline In-Reply-To: <20070608041651.GA19912@linux.vnet.ibm.com> Sender: linux-rt-users-owner@vger.kernel.org List-Id: linux-rt-users.vger.kernel.org On Thu, Jun 07, 2007 at 09:16:51PM -0700, Paul E. McKenney wrote: > On Thu, Jun 07, 2007 at 04:16:09PM -0400, Steven Rostedt wrote: > > On Thu, 2007-06-07 at 14:51 -0400, Steven Rostedt wrote: > > > > > There might still be an issue here. With the patch I'm getting a really > > > slow response time on networking. But that be because of other patches I > > > have applied. > > > > I removed this patch and I can still get the network slowdown/hang. So > > this patch is unrelated to this issue. RCU on the otherhand has not been > > cleared of suspicion. > > Might the slowdown be due to different kernel threads running at different > priorities? I could easily believe that changing the priority of the > kernel thread processing RCU callbacks could have a noticeable effect > on performance in some cases. > > In other news, passed a set of kernbenches at this end, so starting > an rcutorture. And rcutorture passed 8 hours on a 4-CPU Opteron box. Thanx, Paul