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From:   Linus Torvalds <torvalds@linux-foundation.org>
Date:   Sat, 22 Aug 2020 09:05:37 -0700
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Subject: Re: [PATCH 0/4] mm: Simplfy cow handling
To:     Peter Xu <peterx@redhat.com>
Cc:     Linux-MM <linux-mm@kvack.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        "Maya B . Gokhale" <gokhale2@llnl.gov>,
        Yang Shi <yang.shi@linux.alibaba.com>,
        Marty Mcfadden <mcfadden8@llnl.gov>,
        Kirill Shutemov <kirill@shutemov.name>,
        Oleg Nesterov <oleg@redhat.com>, Jann Horn <jannh@google.com>,
        Jan Kara <jack@suse.cz>, Kirill Tkhai <ktkhai@virtuozzo.com>,
        Andrea Arcangeli <aarcange@redhat.com>,
        Christoph Hellwig <hch@lst.de>,
        Andrew Morton <akpm@linux-foundation.org>
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On Fri, Aug 21, 2020 at 4:50 PM Peter Xu <peterx@redhat.com> wrote:
>
>   - Run a busy loop dirty program [1] that uses 6G of memory, restrict to 1G
>     RAM + 5G swap (cgroup).  A few hours later, all things still look good.
>     Make sure to observe (still massive) correct page reuses using the new
>     counter using the last patch, probably when swapping in.
>
>   - Run umapsort [2] to make sure uffd-wp will work again after applying this
>     series upon master 5.9-rc1 (5.9-rc1 is broken).

I obviously like the diffstat, am wondering if you saw any throughput
changes or similar for the busy-loop dirtying thing?

              Linus