From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f179.google.com (mail-pd0-f179.google.com [209.85.192.179]) by kanga.kvack.org (Postfix) with ESMTP id 87219900021 for ; Tue, 28 Oct 2014 08:12:35 -0400 (EDT) Received: by mail-pd0-f179.google.com with SMTP id g10so558881pdj.24 for ; Tue, 28 Oct 2014 05:12:35 -0700 (PDT) Received: from mga03.intel.com (mga03.intel.com. [134.134.136.65]) by mx.google.com with ESMTP id tv2si1245868pac.25.2014.10.28.05.12.33 for ; Tue, 28 Oct 2014 05:12:34 -0700 (PDT) From: Andi Kleen Subject: Re: [PATCH 0/4] Convert khugepaged to a task_work function References: <1414032567-109765-1-git-send-email-athorlton@sgi.com> Date: Tue, 28 Oct 2014 05:12:26 -0700 In-Reply-To: <1414032567-109765-1-git-send-email-athorlton@sgi.com> (Alex Thorlton's message of "Wed, 22 Oct 2014 21:49:23 -0500") Message-ID: <87lho0pf4l.fsf@tassilo.jf.intel.com> MIME-Version: 1.0 Content-Type: text/plain Sender: owner-linux-mm@kvack.org List-ID: To: Alex Thorlton Cc: linux-mm@kvack.org, Andrew Morton , Bob Liu , David Rientjes , "Eric W. Biederman" , Hugh Dickins , Ingo Molnar , Kees Cook , "Kirill A. Shutemov" , Mel Gorman , Oleg Nesterov , Peter Zijlstra , Rik van Riel , Thomas Gleixner , Vladimir Davydov , linux-kernel@vger.kernel.org Alex Thorlton writes: > Last week, while discussing possible fixes for some unexpected/unwanted behavior > from khugepaged (see: https://lkml.org/lkml/2014/10/8/515) several people > mentioned possibly changing changing khugepaged to work as a task_work function > instead of a kernel thread. This will give us finer grained control over the > page collapse scans, eliminate some unnecessary scans since tasks that are > relatively inactive will not be scanned often, and eliminate the unwanted > behavior described in the email thread I mentioned. With your change, what would happen in a single threaded case? Previously one core would scan and another would run the workload. With your change both scanning and running would be on the same core. Would seem like a step backwards to me. -Andi -- ak@linux.intel.com -- Speaking for myself only -- 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