From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx160.postini.com [74.125.245.160]) by kanga.kvack.org (Postfix) with SMTP id C2F376B0044 for ; Mon, 30 Apr 2012 18:12:38 -0400 (EDT) From: Naoya Horiguchi Subject: Re: [PATCH bugfix] proc/pagemap: correctly report non-present ptes and holes between vmas Date: Mon, 30 Apr 2012 18:12:14 -0400 Message-Id: <1335823934-25154-1-git-send-email-n-horiguchi@ah.jp.nec.com> In-Reply-To: <4F9EE5BF.9070005@openvz.org> Sender: owner-linux-mm@kvack.org List-ID: To: khlebnikov@openvz.org Cc: Naoya Horiguchi , Andrew Morton , ak@linux.intel.com, xemul@parallels.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, KAMEZAWA Hiroyuki On Mon, Apr 30, 2012 at 11:19:27PM +0400, Konstantin Khlebnikov wrote: > Naoya Horiguchi wrote: > >Hi, > > > >On Sat, Apr 28, 2012 at 08:22:30PM +0400, Konstantin Khlebnikov wrote: > >>This patch resets current pagemap-entry if current pte isn't present, > >>or if current vma is over. Otherwise pagemap reports last entry again and again. > >> > >>non-present pte reporting was broken in commit v3.3-3738-g092b50b > >>("pagemap: introduce data structure for pagemap entry") > >> > >>reporting for holes was broken in commit v3.3-3734-g5aaabe8 > >>("pagemap: avoid splitting thp when reading /proc/pid/pagemap") > >> > >>Signed-off-by: Konstantin Khlebnikov > >>Reported-by: Pavel Emelyanov > >>Cc: Naoya Horiguchi > >>Cc: KAMEZAWA Hiroyuki > >>Cc: Andi Kleen > > > >Thanks for your efforts. > >I confirmed that this patch fixes the problem on v3.4-rc4. > >But originally (before the commits you pointed to above) initializing > >pagemap entries (originally labelled with confusing 'pfn') were done > >in for-loop in pagemap_pte_range(), so I think it's better to get it > >back to things like that. > > > >How about the following? > > I don't like this. Functions which returns void should always initialize its "output" > argument, it much more clear than relying on preinitialized value. OK, it makes sense. Thanks, Naoya -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org