From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH] increase ple_gap default to 64 Date: Tue, 04 Jan 2011 16:29:05 +0200 Message-ID: <4D232EB1.1000304@redhat.com> References: <20110103101907.2926ecca@annuminas.surriel.com> <4D229221.8070305@intel.com> <4D232C20.80306@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: "Zhai, Edwin" , "linux-kernel@vger.kernel.org" , "kvm@vger.kernel.org" , "mtosatti@redhat.com" To: Rik van Riel Return-path: Received: from mx1.redhat.com ([209.132.183.28]:43669 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751249Ab1ADO3J (ORCPT ); Tue, 4 Jan 2011 09:29:09 -0500 In-Reply-To: <4D232C20.80306@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On 01/04/2011 04:18 PM, Rik van Riel wrote: > On 01/03/2011 10:21 PM, Zhai, Edwin wrote: >> Riel, >> Thanks for your patch. I have changed the ple_gap to 128 on xen side, >> but forget the patch for KVM:( >> >> A little bit big is no harm, but more perf data is better. > > So should I resend the patch with the ple_gap default > changed to 128, or are you willing to ack the current > patch? > I think 128 is safer given than 41 was too low. We have to take into account newer cpus and slower spin loops. If the spin loop does a cache ping-pong (which would be a bad, bad possible, implementation), even 128 might be too low. -- error compiling committee.c: too many arguments to function