From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Fri, 11 May 2007 11:05:22 -0700 From: Andrew Morton Subject: Re: [PATCH 1/2] scalable rw_mutex Message-Id: <20070511110522.ed459635.akpm@linux-foundation.org> In-Reply-To: References: <20070511131541.992688403@chello.nl> <20070511132321.895740140@chello.nl> <20070511093108.495feb70.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Christoph Lameter Cc: Peter Zijlstra , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Oleg Nesterov , Ingo Molnar , Thomas Gleixner , Nick Piggin List-ID: On Fri, 11 May 2007 10:07:17 -0700 (PDT) Christoph Lameter wrote: > On Fri, 11 May 2007, Andrew Morton wrote: > > > yipes. percpu_counter_sum() is expensive. > > Capable of triggering NMI watchdog on 4096+ processors? Well. That would be a millisecond per cpu which sounds improbable. And we'd need to be calling it under local_irq_save() which we presently don't. And nobody has reported any problems against the existing callsites. But it's no speed demon, that's for sure. -- 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