From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx113.postini.com [74.125.245.113]) by kanga.kvack.org (Postfix) with SMTP id EB8546B0044 for ; Tue, 6 Nov 2012 13:56:04 -0500 (EST) Message-ID: <50995DD2.8000200@redhat.com> Date: Tue, 06 Nov 2012 13:58:26 -0500 From: Rik van Riel MIME-Version: 1.0 Subject: Re: [PATCH 08/19] mm: numa: Create basic numa page hinting infrastructure References: <1352193295-26815-1-git-send-email-mgorman@suse.de> <1352193295-26815-9-git-send-email-mgorman@suse.de> In-Reply-To: <1352193295-26815-9-git-send-email-mgorman@suse.de> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Mel Gorman Cc: Peter Zijlstra , Andrea Arcangeli , Ingo Molnar , Johannes Weiner , Hugh Dickins , Thomas Gleixner , Linus Torvalds , Andrew Morton , Linux-MM , LKML On 11/06/2012 04:14 AM, Mel Gorman wrote: > Note: This patch started as "mm/mpol: Create special PROT_NONE > infrastructure" and preserves the basic idea but steals *very* > heavily from "autonuma: numa hinting page faults entry points" for > the actual fault handlers without the migration parts. The end > result is barely recognisable as either patch so all Signed-off > and Reviewed-bys are dropped. If Peter, Ingo and Andrea are ok with > this version, I will re-add the signed-offs-by to reflect the history. > > In order to facilitate a lazy -- fault driven -- migration of pages, create > a special transient PAGE_NUMA variant, we can then use the 'spurious' > protection faults to drive our migrations from. > > Pages that already had an effective PROT_NONE mapping will not be detected The patch itself is good, but the changelog needs a little fix. While you are defining _PAGE_NUMA to _PAGE_PROTNONE on x86, this may be different on other architectures. Therefore, the changelog should refer to PAGE_NUMA, not PROT_NONE. > to generate these 'spurious' faults for the simple reason that we cannot > distinguish them on their protection bits, see pte_numa(). This isn't > a problem since PROT_NONE (and possible PROT_WRITE with dirty tracking) > aren't used or are rare enough for us to not care about their placement. > > Signed-off-by: Mel Gorman Other than the changelog ... Reviewed-by: Rik van Riel -- 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