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Date:   Tue, 27 Jun 2023 12:22:01 -0700
From:   Andrew Morton <akpm@linux-foundation.org>
To:     Nanyong Sun <sunnanyong@huawei.com>
Cc:     <xu.xin16@zte.com.cn>, <wangkefeng.wang@huawei.com>,
        <linux-kernel@vger.kernel.org>, <linux-mm@kvack.org>
Subject: Re: [PATCH] mm/ksm: delete the redundant ksm_merging_pages
 interafce in proc
Message-Id: <20230627122201.6e25819493823dfc7cca4741@linux-foundation.org>
In-Reply-To: <20230627133542.2446285-1-sunnanyong@huawei.com>
References: <20230627133542.2446285-1-sunnanyong@huawei.com>
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On Tue, 27 Jun 2023 21:35:42 +0800 Nanyong Sun <sunnanyong@huawei.com> wrote:

> Since the ksm_merging_pages information already included in
> /proc/<pid>/ksm_stat, we can delete /proc/<pid>/ksm_merging_pages to
> make the directory more clean, and can save a little bit resources.

Well, this is a non backward compatible change - any userspace
which depends on ksm_merging_pages will break.

Yes, we could remove this but it will be a lengthy process involving
emitting a "please use ksm_stat instead" message for a few
years before removal.