From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753284AbbDPRkB (ORCPT ); Thu, 16 Apr 2015 13:40:01 -0400 Received: from cantor2.suse.de ([195.135.220.15]:43736 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751207AbbDPRjw (ORCPT ); Thu, 16 Apr 2015 13:39:52 -0400 Date: Thu, 16 Apr 2015 18:39:48 +0100 From: Mel Gorman To: Dave Hansen Cc: Linux-MM , Rik van Riel , Hugh Dickins , Minchan Kim , Andi Kleen , LKML Subject: Re: [PATCH 1/4] x86, mm: Trace when an IPI is about to be sent Message-ID: <20150416173948.GR14842@suse.de> References: <1429179766-26711-1-git-send-email-mgorman@suse.de> <1429179766-26711-2-git-send-email-mgorman@suse.de> <552FE98F.2080705@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <552FE98F.2080705@intel.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Apr 16, 2015 at 09:55:43AM -0700, Dave Hansen wrote: > On 04/16/2015 03:22 AM, Mel Gorman wrote: > > It is easy to trace when an IPI is received to flush a TLB but harder to > > detect what event sent it. This patch makes it easy to identify the source > > of IPIs being transmitted for TLB flushes on x86. > > Looks fine to me. I think I even thought about adding this but didn't > see an immediate need for it. I guess this does let you see how many > IPIs are sent vs. received. > It would but that's not why I wanted it. I wanted a stack track of who was sending the IPI and I can't get that on the receive side. I could have used perf probe and some hackery but this seemed useful in itself. > Reviewed-by: Dave Hansen Thanks. -- Mel Gorman SUSE Labs