From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752897AbaEUTet (ORCPT ); Wed, 21 May 2014 15:34:49 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:48255 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752629AbaEUTes (ORCPT ); Wed, 21 May 2014 15:34:48 -0400 Date: Wed, 21 May 2014 12:34:46 -0700 From: Andrew Morton To: "Kirill A. Shutemov" Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Andrea Arcangeli , Pavel Emelyanov , Cyrill Gorcunov , Dave Hansen Subject: Re: [PATCH] mm: /prom/pid/clear_refs: avoid split_huge_page() Message-Id: <20140521123446.ae45fa676cae27fffbd96cfd@linux-foundation.org> In-Reply-To: <1400699062-20123-1-git-send-email-kirill.shutemov@linux.intel.com> References: <1400699062-20123-1-git-send-email-kirill.shutemov@linux.intel.com> X-Mailer: Sylpheed 3.2.0beta5 (GTK+ 2.24.10; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 21 May 2014 22:04:22 +0300 "Kirill A. Shutemov" wrote: > Currently we split all THP pages on any clear_refs request. It's not > necessary. We can handle this on PMD level. > > One side effect is that soft dirty will potentially see more dirty > memory, since we will mark whole THP page dirty at once. This clashes pretty badly with http://ozlabs.org/~akpm/mmots/broken-out/clear_refs-redefine-callback-functions-for-page-table-walker.patch > Sanity checked with CRIU test suite. More testing is required. Will you be doing that testing or was this a request for Cyrill & co to help? Perhaps this is post-3.15 material.