From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755433Ab3JIH3O (ORCPT ); Wed, 9 Oct 2013 03:29:14 -0400 Received: from merlin.infradead.org ([205.233.59.134]:60617 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751798Ab3JIH3N (ORCPT ); Wed, 9 Oct 2013 03:29:13 -0400 Date: Wed, 9 Oct 2013 09:28:38 +0200 From: Peter Zijlstra To: Ingo Molnar Cc: Tim Chen , Ingo Molnar , Andrew Morton , Linus Torvalds , Andrea Arcangeli , Alex Shi , Andi Kleen , Michel Lespinasse , Davidlohr Bueso , Matthew R Wilcox , Dave Hansen , Rik van Riel , Peter Hurley , "Paul E.McKenney" , Jason Low , Waiman Long , linux-kernel@vger.kernel.org, linux-mm Subject: Re: [PATCH v8 0/9] rwsem performance optimizations Message-ID: <20131009072838.GY3081@twins.programming.kicks-ass.net> References: <1380753493.11046.82.camel@schen9-DESK> <20131003073212.GC5775@gmail.com> <1381186674.11046.105.camel@schen9-DESK> <20131009061551.GD7664@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20131009061551.GD7664@gmail.com> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Oct 09, 2013 at 08:15:51AM +0200, Ingo Molnar wrote: > So I'd expect this to be a rather sensitive workload and you'd have to > actively engineer it to hit the effect PeterZ mentioned. I could imagine > MPI workloads to run into such patterns - but not deterministically. The workload that I got the report from was a virus scanner, it would spawn nr_cpus threads and {mmap file, scan content, munmap} through your filesystem. Now if I only could remember who reported this.. :/ From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pb0-f50.google.com (mail-pb0-f50.google.com [209.85.160.50]) by kanga.kvack.org (Postfix) with ESMTP id E3BF46B0036 for ; Wed, 9 Oct 2013 03:29:09 -0400 (EDT) Received: by mail-pb0-f50.google.com with SMTP id uo5so503236pbc.9 for ; Wed, 09 Oct 2013 00:29:09 -0700 (PDT) Date: Wed, 9 Oct 2013 09:28:38 +0200 From: Peter Zijlstra Subject: Re: [PATCH v8 0/9] rwsem performance optimizations Message-ID: <20131009072838.GY3081@twins.programming.kicks-ass.net> References: <1380753493.11046.82.camel@schen9-DESK> <20131003073212.GC5775@gmail.com> <1381186674.11046.105.camel@schen9-DESK> <20131009061551.GD7664@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20131009061551.GD7664@gmail.com> Sender: owner-linux-mm@kvack.org List-ID: To: Ingo Molnar Cc: Tim Chen , Ingo Molnar , Andrew Morton , Linus Torvalds , Andrea Arcangeli , Alex Shi , Andi Kleen , Michel Lespinasse , Davidlohr Bueso , Matthew R Wilcox , Dave Hansen , Rik van Riel , Peter Hurley , "Paul E.McKenney" , Jason Low , Waiman Long , linux-kernel@vger.kernel.org, linux-mm On Wed, Oct 09, 2013 at 08:15:51AM +0200, Ingo Molnar wrote: > So I'd expect this to be a rather sensitive workload and you'd have to > actively engineer it to hit the effect PeterZ mentioned. I could imagine > MPI workloads to run into such patterns - but not deterministically. The workload that I got the report from was a virus scanner, it would spawn nr_cpus threads and {mmap file, scan content, munmap} through your filesystem. Now if I only could remember who reported this.. :/ -- 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/ . Don't email: email@kvack.org