Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756465Ab2EAMrH (ORCPT ); Tue, 1 May 2012 08:47:07 -0400 Received: from mail-vx0-f174.google.com ([209.85.220.174]:38395 "EHLO mail-vx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753303Ab2EAMrF (ORCPT ); Tue, 1 May 2012 08:47:05 -0400 MIME-Version: 1.0 In-Reply-To: References: Date: Tue, 1 May 2012 05:47:04 -0700 X-Google-Sender-Auth: WkBLcVZB8jfWt5SgdMhwyWxGCe8 Message-ID: Subject: Re: read() syscall slowing down due to other threads? From: George Porter To: Nick Piggin Cc: linux-kernel@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 793 Lines: 19 On Mon, Apr 30, 2012 at 11:40 PM, Nick Piggin wrote: > It could be memory or coherency traffic that's causing a slowdown across > the system? > > Could a dynamic core frequency / thermal throttling explain any of the > slowdown? Thanks for these suggestions. I checked the BIOS, and indeed it was set to "Hybrid power/performance." I just reset the server to "Static high performance" which I believe turns off processor frequency power optimizations. I'll re-run our workload and see if that has an effect. Thanks, George -- 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/