Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751930Ab0KWE5U (ORCPT ); Mon, 22 Nov 2010 23:57:20 -0500 Received: from mail-iw0-f174.google.com ([209.85.214.174]:53607 "EHLO mail-iw0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751719Ab0KWE5T convert rfc822-to-8bit (ORCPT ); Mon, 22 Nov 2010 23:57:19 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=svoYIo2EWY66N+oBRksXMG9TmltTPXYEYrFcz7whNVe9xLDTlsYjJ1F3QYtf2+zhXD YVnIZbsMSXbWGxQ0iNdpVo2ST2cCmBSX+BBEmnD+W9mczTUKIVhlkQj11Wyif8XKabF8 q2/LGF94AIReUZD0dWKu5+TKe2y3KeuPmfJFg= MIME-Version: 1.0 In-Reply-To: <20101122142109.2f3e168c.akpm@linux-foundation.org> References: <5d205f8a4df078b0da3681063bbf37382b02dd23.1290349672.git.minchan.kim@gmail.com> <20101122142109.2f3e168c.akpm@linux-foundation.org> Date: Tue, 23 Nov 2010 13:57:17 +0900 Message-ID: Subject: Re: [RFC 2/2] Prevent promotion of page in madvise_dontneed From: Minchan Kim To: Andrew Morton Cc: linux-mm , LKML , Rik van Riel , KOSAKI Motohiro , Johannes Weiner , Nick Piggin Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1844 Lines: 51 On Tue, Nov 23, 2010 at 7:21 AM, Andrew Morton wrote: > On Sun, 21 Nov 2010 23:30:24 +0900 > Minchan Kim wrote: > >> Now zap_pte_range alwayas promotes pages which are pte_young && >> !VM_SequentialReadHint(vma). But in case of calling MADV_DONTNEED, >> it's unnecessary since the page wouldn't use any more. >> >> If the page is sharred by other processes and it's real working set > > This patch doesn't actually do anything. ?It passes variable `promote' > all the way down to unmap_vmas(), but unmap_vmas() doesn't use that new > variable. Oops. Sorry for that. I will resend the patch with your fixlet and Ben's point. Thank you. > Have a comment fixlet: > > --- a/mm/memory.c~mm-prevent-promotion-of-page-in-madvise_dontneed-fix > +++ a/mm/memory.c > @@ -1075,7 +1075,7 @@ static unsigned long unmap_page_range(st > ?* @end_addr: virtual address at which to end unmapping > ?* @nr_accounted: Place number of unmapped pages in vm-accountable vma's here > ?* @details: details of nonlinear truncation or shared cache invalidation > - * @promote: whether pages inclued vma would be promoted or not > + * @promote: whether pages included in the vma should be promoted or not > ?* > ?* Returns the end address of the unmapping (restart addr if interrupted). > ?* > _ > > Also, I'd suggest that we avoid introducing the term "promote". ?It > isn't a term which is presently used in Linux MM. ?Probably "activate" > has a better-known meaning. > > And `activate' could be a bool if one is in the mood for that. > -- Kind regards, Minchan Kim -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/