From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751537AbdFIB5r (ORCPT ); Thu, 8 Jun 2017 21:57:47 -0400 Received: from szxga02-in.huawei.com ([45.249.212.188]:7344 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751445AbdFIB5p (ORCPT ); Thu, 8 Jun 2017 21:57:45 -0400 Message-ID: <593A0080.4040806@huawei.com> Date: Fri, 9 Jun 2017 09:57:20 +0800 From: zhong jiang User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:12.0) Gecko/20120428 Thunderbird/12.0.1 MIME-Version: 1.0 To: Minchan Kim , CC: , , Subject: Re: [PATCH] mm: correct the comment when reclaimed pages exceed the scanned pages References: <1496824266-25235-1-git-send-email-zhongjiang@huawei.com> <20170608064658.GA9190@bbox> In-Reply-To: <20170608064658.GA9190@bbox> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.177.29.68] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A090201.593A0095.008A,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=0.0.0.0, so=2014-11-16 11:51:01, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: 564e14e1eeb23481d7c6bc40eff7eef0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2017/6/8 14:46, Minchan Kim wrote: > 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. > > > . > Thanks Regards zhongjiang