Date: Wed, 7 Jun 2017 15:12:16 +0900
From: Minchan Kim <minchan@kernel.org>
To: zhong jiang <zhongjiang@huawei.com>
CC: <akpm@linux-foundation.org>, <vinayakm.list@gmail.com>,
        <mhocko@suse.com>, <linux-mm@kvack.org>,
        <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] Revert "mm: vmpressure: fix sending wrong events on
 underflow"
Message-ID: <20170607061216.GA5929@bbox>
References: <1496804917-7628-1-git-send-email-zhongjiang@huawei.com>
 <20170607035540.GA5687@bbox>
 <59378799.1050000@huawei.com>
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On Wed, Jun 07, 2017 at 12:56:57PM +0800, zhong jiang wrote:
> On 2017/6/7 11:55, Minchan Kim wrote:
> > On Wed, Jun 07, 2017 at 11:08:37AM +0800, zhongjiang wrote:
> >> This reverts commit e1587a4945408faa58d0485002c110eb2454740c.
> >>
> >> THP lru page is reclaimed , THP is split to normal page and loop again.
> >> reclaimed pages should not be bigger than nr_scan.  because of each
> >> loop will increase nr_scan counter.
> > Unfortunately, there is still underflow issue caused by slab pages as
> > Vinayak reported in description of e1587a4945408 so we cannot revert.
> > Please correct comment instead of removing the logic.
> >
> > Thanks.
>   we calculate the vmpressue based on the Lru page, exclude the slab pages by previous
>   discussion.    is it not this?
> 

IIRC, It is not merged into mainline although mmotm has it.