From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ee0-f53.google.com (mail-ee0-f53.google.com [74.125.83.53]) by kanga.kvack.org (Postfix) with ESMTP id A41686B0081 for ; Tue, 10 Dec 2013 03:43:00 -0500 (EST) Received: by mail-ee0-f53.google.com with SMTP id b57so2050581eek.12 for ; Tue, 10 Dec 2013 00:43:00 -0800 (PST) Received: from mx2.suse.de (cantor2.suse.de. [195.135.220.15]) by mx.google.com with ESMTP id h45si13345992eeo.25.2013.12.10.00.42.59 for ; Tue, 10 Dec 2013 00:42:59 -0800 (PST) Date: Tue, 10 Dec 2013 08:42:57 +0000 From: Mel Gorman Subject: Re: [PATCH 17/18] sched: Tracepoint task movement Message-ID: <20131210084257.GD11295@suse.de> References: <1386572952-1191-1-git-send-email-mgorman@suse.de> <1386572952-1191-18-git-send-email-mgorman@suse.de> <52A611FB.7000305@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <52A611FB.7000305@redhat.com> Sender: owner-linux-mm@kvack.org List-ID: To: Rik van Riel Cc: Andrew Morton , Alex Thorlton , Linux-MM , LKML , Drew Jones On Mon, Dec 09, 2013 at 01:54:51PM -0500, Rik van Riel wrote: > On 12/09/2013 02:09 AM, Mel Gorman wrote: > > move_task() is called from move_one_task and move_tasks and is an > > approximation of load balancer activity. We should be able to track > > tasks that move between CPUs frequently. If the tracepoint included node > > information then we could distinguish between in-node and between-node > > traffic for load balancer decisions. The tracepoint allows us to track > > local migrations, remote migrations and average task migrations. > > > > Signed-off-by: Mel Gorman > > Does this replicate the task_sched_migrate_task tracepoint in > set_task_cpu() ? > There is significant overlap but bits missing. We do not necessarily know where the task was previously running and whether this is a local->remote migration. We also cannot tell the difference between load balancer activity, numa balancing and try_to_wake_up. Still, you're right, this patch is not painting a full picture either. I'll drop it for now and look at improving the existing task_sched_migrate_task tracepoint. -- Mel Gorman SUSE Labs -- 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