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Date:   Thu, 12 May 2022 17:36:20 -0700
From:   Andrew Morton <akpm@linux-foundation.org>
To:     Peter Xu <peterx@redhat.com>
Cc:     David Hildenbrand <david@redhat.com>,
        Bibo Mao <maobibo@loongson.cn>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org, Yang Shi <shy828301@gmail.com>
Subject: Re: [PATCH v3] mm/khugepaged: sched to numa node when collapse huge
 page
Message-Id: <20220512173620.2f5175c7a321e6ccea6e58e9@linux-foundation.org>
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References: <20220317065024.2635069-1-maobibo@loongson.cn>
        <3a441789-b3e4-236e-2e44-e7a1c7258a94@redhat.com>
        <YmrB/7ehG2kj2RMn@xz-m1.local>
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On Thu, 28 Apr 2022 12:34:07 -0400 Peter Xu <peterx@redhat.com> wrote:

> On Thu, Apr 28, 2022 at 05:17:07PM +0200, David Hildenbrand wrote:
> > On 17.03.22 07:50, Bibo Mao wrote:
> > > collapse huge page will copy huge page from general small pages,
> > > dest node is calculated from most one of source pages, however
> > > THP daemon is not scheduled on dest node. The performance may be
> > > poor since huge page copying across nodes, also cache is not used
> > > for target node. With this patch, khugepaged daemon switches to
> > > the same numa node with huge page. It saves copying time and makes
> > > use of local cache better.
> > > 
> > > With this patch, specint 2006 base performance is improved with 6%
> > > on Loongson 3C5000L platform with 32 cores and 8 numa nodes.
> > 
> > If it helps, that's nice as long as it doesn't hurt other cases.
> > 

Quite a bit of doubtful feedback and we have yet to hear from the
author.  I'll drop the patch.

Bibo, please resend at a later time if you feel the patch remains
desirable.  Please attempt to address the feedback via code changes
and/or changelogging.