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From:   ye xingchen <yexingchen116@gmail.com>
To:     mcgrof@kernel.org
Cc:     akpm@linux-foundation.org, chi.minghao@zte.com.cn,
        hch@infradead.org, keescook@chromium.org, linmiaohe@huawei.com,
        linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-mm@kvack.org, vbabka@suse.cz, willy@infradead.org,
        ye.xingchen@zte.com.cn, yzaikin@google.com
Subject: Re: [PATCH V5 1/2] mm: compaction: move compaction sysctl to its own file
Date:   Fri, 24 Mar 2023 06:24:08 +0000
Message-Id: <20230324062408.49217-1-ye.xingchen@zte.com.cn>
In-Reply-To: <ZByq/TcnxYbeReJZ@bombadil.infradead.org>
References: <ZByq/TcnxYbeReJZ@bombadil.infradead.org>
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>$ ./scripts/bloat-o-meter vmlinux.old vmlinux
>add/remove: 1/0 grow/shrink: 1/2 up/down: 346/-350 (-4)
>Function                                     old     new   delta
>vm_compaction                                  -     320    +320
>kcompactd_init                               167     193     +26
>proc_dointvec_minmax_warn_RT_change          104      10     -94
>vm_table                                    2112    1856    -256
>Total: Before=19287558, After=19287554, chg -0.00%
>
>So I don't think we need to pause this move or others where are have savings.
>
>Minghao, can you fix the commit log, and explain how you are also saving
>4 bytes as per the above bloat-o-meter results?

$ ./scripts/bloat-o-meter vmlinux vmlinux.new
add/remove: 1/0 grow/shrink: 1/1 up/down: 350/-256 (94)
Function                                     old     new   delta
vm_compaction                                  -     320    +320
kcompactd_init                               180     210     +30
vm_table                                    2112    1856    -256
Total: Before=21104198, After=21104292, chg +0.00%

In my environment, kcompactd_init increases by 30 instead of 26.
And proc_dointvec_minmax_warn_RT_change No expansion.

  minghao