Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161251AbWASHfX (ORCPT ); Thu, 19 Jan 2006 02:35:23 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1161246AbWASHfW (ORCPT ); Thu, 19 Jan 2006 02:35:22 -0500 Received: from viper.oldcity.dca.net ([216.158.38.4]:48063 "HELO viper.oldcity.dca.net") by vger.kernel.org with SMTP id S1161251AbWASHfV (ORCPT ); Thu, 19 Jan 2006 02:35:21 -0500 Subject: Re: 2.6.15-rc5: latency regression vs 2.6.14 in exit_mmap->free_pgtables From: Lee Revell To: Hugh Dickins Cc: linux-kernel , Ingo Molnar , Linus Torvalds In-Reply-To: References: <1135726300.22744.25.camel@mindpipe> <1137634961.626.2.camel@mindpipe> Content-Type: text/plain Date: Thu, 19 Jan 2006 02:35:18 -0500 Message-Id: <1137656119.4736.39.camel@mindpipe> Mime-Version: 1.0 X-Mailer: Evolution 2.5.4 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1355 Lines: 30 On Thu, 2006-01-19 at 07:29 +0000, Hugh Dickins wrote: > On Wed, 18 Jan 2006, Lee Revell wrote: > > On Wed, 2005-12-28 at 22:59 +0000, Hugh Dickins wrote: > > > > > > On my list to work on; but the TLB always needs great care, and this > > > goes down into architectural divergences, with truncation of a mapped > > > file adding further awkward constraints. I imagine 2.6.16-rc1 is only > > > a couple of weeks away, so it's unlikely to be fixed in 2.6.16 either. > > > > Is this believed to be fixed in 2.6.16-rc1? > > Not at all, I'm afraid. Do you think I ought to try to persuade Linus > and Andrew to take that ugly free_pgtables #ifdef CONFIG_PREEMPT patch > in the interim before we've the proper latency fix there? (I doubt the > mmu_gather rewrite in 2.6.17 too, but perhaps a reasonable compromise.) For the time being, this is overshadowed by long latencies (~8ms or so) in rt_garbage_collect() and rt_run_flush(). Previously I was under the impression those could be worked around by sysctl/proc tuning, but this is not the case. Until those are fixed I would say it's low priority. Lee - 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/