From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750923AbcFVEXE (ORCPT ); Wed, 22 Jun 2016 00:23:04 -0400 Received: from mail-pa0-f65.google.com ([209.85.220.65]:35584 "EHLO mail-pa0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750727AbcFVEXB (ORCPT ); Wed, 22 Jun 2016 00:23:01 -0400 Date: Wed, 22 Jun 2016 11:27:51 +0800 From: Ganesh Mahendran To: David Rientjes Cc: devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org, gregkh@linuxfoundation.org, arve@android.com, riandrews@android.com Subject: Re: [PATCH 2/3] staging: lowmemorykiller: count anon pages only when we have swap devices Message-ID: <20160622032751.GB5683@leo-test> References: <1466487018-5410-1-git-send-email-opensource.ganesh@gmail.com> <1466487018-5410-2-git-send-email-opensource.ganesh@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, David: On Tue, Jun 21, 2016 at 01:22:00PM -0700, David Rientjes wrote: > On Tue, 21 Jun 2016, Ganesh Mahendran wrote: > > > lowmem_count() should only count anon pages when we have swap device. > > > > Why? I make a mistake. I thought lowmem_count will return the shrinkalbe page of a process. > > > Signed-off-by: Ganesh Mahendran > > --- > > drivers/staging/android/lowmemorykiller.c | 12 ++++++++---- > > 1 file changed, 8 insertions(+), 4 deletions(-) > > > > diff --git a/drivers/staging/android/lowmemorykiller.c b/drivers/staging/android/lowmemorykiller.c > > index 6da9260..1d8de47 100644 > > --- a/drivers/staging/android/lowmemorykiller.c > > +++ b/drivers/staging/android/lowmemorykiller.c > > @@ -73,10 +73,14 @@ static unsigned long lowmem_deathpending_timeout; > > static unsigned long lowmem_count(struct shrinker *s, > > struct shrink_control *sc) > > { > > - return global_page_state(NR_ACTIVE_ANON) + > > - global_page_state(NR_ACTIVE_FILE) + > > - global_page_state(NR_INACTIVE_ANON) + > > - global_page_state(NR_INACTIVE_FILE); > > + unsigned long freeable = global_page_state(NR_ACTIVE_FILE) + > > + global_page_state(NR_INACTIVE_FILE); > > + > > + if (get_nr_swap_pages() > 0) > > + freeable += global_page_state(NR_ACTIVE_ANON) + > > + global_page_state(NR_INACTIVE_ANON); > > + > > + return freeable; > > } > > > > static unsigned long lowmem_scan(struct shrinker *s, struct shrink_control *sc) > > Shouldn't this be advertising the amount of memory that is freeable by > killing the process with the highest priority oom_score_adj? It's not > legitimate to say it can free all anon and file memory if nothing is oom > killable, so this function is wrong both originally and with your patched > version. Yes, so should we just simply return 1 to make do_shrink_slab() go ahead? Then lowmem_scan() will do the real job to scan all the process. Thanks.