From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lf0-f71.google.com (mail-lf0-f71.google.com [209.85.215.71]) by kanga.kvack.org (Postfix) with ESMTP id DD5CE6B0005 for ; Thu, 16 Jun 2016 11:10:52 -0400 (EDT) Received: by mail-lf0-f71.google.com with SMTP id g18so28619117lfg.2 for ; Thu, 16 Jun 2016 08:10:52 -0700 (PDT) Received: from mail-wm0-f67.google.com (mail-wm0-f67.google.com. [74.125.82.67]) by mx.google.com with ESMTPS id gh2si5890182wjd.127.2016.06.16.08.10.51 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 16 Jun 2016 08:10:51 -0700 (PDT) Received: by mail-wm0-f67.google.com with SMTP id k184so12189101wme.2 for ; Thu, 16 Jun 2016 08:10:51 -0700 (PDT) Date: Thu, 16 Jun 2016 17:10:49 +0200 From: Michal Hocko Subject: Re: [PATCH 1/2] Revert "mm: make faultaround produce old ptes" Message-ID: <20160616151049.GM6836@dhcp22.suse.cz> References: <1465893750-44080-1-git-send-email-kirill.shutemov@linux.intel.com> <1465893750-44080-2-git-send-email-kirill.shutemov@linux.intel.com> <20160616122001.GJ6836@dhcp22.suse.cz> <20160616122735.GB108167@black.fi.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160616122735.GB108167@black.fi.intel.com> Sender: owner-linux-mm@kvack.org List-ID: To: "Kirill A. Shutemov" Cc: Linus Torvalds , Andrew Morton , Rik van Riel , Mel Gorman , "Huang, Ying" , Minchan Kim , Vinayak Menon , Dave Hansen , linux-kernel@vger.kernel.org, linux-mm@kvack.org On Thu 16-06-16 15:27:35, Kirill A. Shutemov wrote: > On Thu, Jun 16, 2016 at 02:20:02PM +0200, Michal Hocko wrote: > > On Tue 14-06-16 11:42:29, Kirill A. Shutemov wrote: > > > This reverts commit 5c0a85fad949212b3e059692deecdeed74ae7ec7. > > > > > > The commit causes ~6% regression in unixbench. > > > > Is the regression fully explained? My understanding from the email > > thread is that this is suspiciously too high. It is not like I would > > be against the revert but having an explanation would be really > > appreciated. > > My understanding is that it's overhead on setting accessed bit: > > http://lkml.kernel.org/r/20160613125248.GA30109@black.fi.intel.com But those numbers cannot explain the regression completely AFAIU. It smells like something else is going on. Anyway, as I've said I do not have anything against the revert just more than "unixbench regresses" would be nice. -- Michal Hocko 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