From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f50.google.com (mail-pa0-f50.google.com [209.85.220.50]) by kanga.kvack.org (Postfix) with ESMTP id DE21E6B0032 for ; Wed, 25 Mar 2015 19:09:48 -0400 (EDT) Received: by pacwe9 with SMTP id we9so43666479pac.1 for ; Wed, 25 Mar 2015 16:09:48 -0700 (PDT) Received: from mail-pd0-x236.google.com (mail-pd0-x236.google.com. [2607:f8b0:400e:c02::236]) by mx.google.com with ESMTPS id gl5si5659017pbc.6.2015.03.25.16.09.47 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 25 Mar 2015 16:09:48 -0700 (PDT) Received: by pdbcz9 with SMTP id cz9so43016896pdb.3 for ; Wed, 25 Mar 2015 16:09:47 -0700 (PDT) Date: Wed, 25 Mar 2015 16:09:38 -0700 (PDT) From: Hugh Dickins Subject: Re: [PATCH] mm: avoid tail page refcounting on non-THP compound pages In-Reply-To: <20150325225633.GA14549@node.dhcp.inet.fi> Message-ID: References: <1427323275-114866-1-git-send-email-kirill.shutemov@linux.intel.com> <20150325225633.GA14549@node.dhcp.inet.fi> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: "Kirill A. Shutemov" Cc: Hugh Dickins , "Kirill A. Shutemov" , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org On Thu, 26 Mar 2015, Kirill A. Shutemov wrote: > On Wed, Mar 25, 2015 at 03:48:48PM -0700, Hugh Dickins wrote: > > On Wed, 25 Mar 2015, Hugh Dickins wrote: > > > On Thu, 26 Mar 2015, Kirill A. Shutemov wrote: > > > > > > > > Since currently all THP pages are anonymous and all drivers pages are > > > > not, we can fix the __compound_tail_refcounted() check by requiring > > > > PageAnon() to enable tail page refcounting. > > > > > > > > Signed-off-by: Kirill A. Shutemov > > > > > > Acked-by: Hugh Dickins > > > > Oh, hold on a moment: does this actually build in a tree without your > > page-flags.h consolidation? It didn't when I tried to add a PageAnon > > test there for my series against v3.19, has something changed in v4.0? > > No. I haven't tried to build it without my patchset, but it seems it > wouldn't. > > Just check: it would build for me on top of [PATCH 01/16], you've acked. Yes, I'm happy with your 1/16 (which is already there in mmotm), it's just that I'd imagined this __compound_tail_refcounted() fix should go to v4.0 (if not stable too: you've decided against, okay). What do you think, should Andrew hold it back for v4.1, or should your page-flags.h accelerate into v4.0 as precondition for this fix? Either is fine with me; but if the latter, then a week's exposure in linux-next first would probably be best. Hugh -- 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