From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f200.google.com (mail-pf0-f200.google.com [209.85.192.200]) by kanga.kvack.org (Postfix) with ESMTP id BB7416B0279 for ; Thu, 8 Jun 2017 02:47:01 -0400 (EDT) Received: by mail-pf0-f200.google.com with SMTP id n81so11859428pfb.14 for ; Wed, 07 Jun 2017 23:47:01 -0700 (PDT) Received: from lgeamrelo12.lge.com (LGEAMRELO12.lge.com. [156.147.23.52]) by mx.google.com with ESMTP id 20si3771472pft.334.2017.06.07.23.47.00 for ; Wed, 07 Jun 2017 23:47:01 -0700 (PDT) Date: Thu, 8 Jun 2017 15:46:58 +0900 From: Minchan Kim Subject: Re: [PATCH] mm: correct the comment when reclaimed pages exceed the scanned pages Message-ID: <20170608064658.GA9190@bbox> References: <1496824266-25235-1-git-send-email-zhongjiang@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1496824266-25235-1-git-send-email-zhongjiang@huawei.com> Sender: owner-linux-mm@kvack.org List-ID: To: zhongjiang Cc: akpm@linux-foundation.org, vinayakm.list@gmail.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org On Wed, Jun 07, 2017 at 04:31:06PM +0800, zhongjiang wrote: > The commit e1587a494540 ("mm: vmpressure: fix sending wrong events on > underflow") declare that reclaimed pages exceed the scanned pages due > to the thp reclaim. it is incorrect because THP will be spilt to normal > page and loop again. which will result in the scanned pages increment. > > Signed-off-by: zhongjiang > --- > mm/vmpressure.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/mm/vmpressure.c b/mm/vmpressure.c > index 6063581..0e91ba3 100644 > --- a/mm/vmpressure.c > +++ b/mm/vmpressure.c > @@ -116,8 +116,9 @@ static enum vmpressure_levels vmpressure_calc_level(unsigned long scanned, > > /* > * reclaimed can be greater than scanned in cases > - * like THP, where the scanned is 1 and reclaimed > - * could be 512 > + * like reclaimed slab pages, shrink_node just add > + * reclaimed page without a related increment to > + * scanned pages. > */ > if (reclaimed >= scanned) > goto out; Thanks for the fixing my fault! Acked-by: Minchan Kim Frankly speaking, I'm not sure we need such comment in there at the cost of maintainance because it would be fragile but easy to fix by above simple condition so I think it would be better to remove that comment but others might be different. So, don't have any objection. -- 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