From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lb0-f174.google.com (mail-lb0-f174.google.com [209.85.217.174]) by kanga.kvack.org (Postfix) with ESMTP id 22F31900021 for ; Mon, 27 Oct 2014 16:40:07 -0400 (EDT) Received: by mail-lb0-f174.google.com with SMTP id p9so6422833lbv.19 for ; Mon, 27 Oct 2014 13:40:06 -0700 (PDT) Received: from mail.ud10.udmedia.de (ud10.udmedia.de. [194.117.254.50]) by mx.google.com with ESMTPS id j9si21754399lab.13.2014.10.27.13.40.04 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 27 Oct 2014 13:40:05 -0700 (PDT) Date: Mon, 27 Oct 2014 21:40:03 +0100 From: Markus Trippelsdorf Subject: isolate_freepages_block(): very high intermittent overhead Message-ID: <20141027204003.GB348@x4> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Sender: owner-linux-mm@kvack.org List-ID: To: linux-mm@kvack.org Cc: Vlastimil Babka On my v3.18-rc2 kernel isolate_freepages_block() sometimes shows up very high (>20%) in perf top during the configuration phase of software builds. It increases build time considerably. Unfortunately the issue is not 100% reproducible, because it appears only intermittently. And the symptoms vanish after a few minutes. I think the "mm, compaction" series from Vlastimil is to blame, but it's hard to be sure when bisection doesn't work. -- Markus -- 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