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Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: <492be1c2-9078-1923-51f9-e01156455ea1@redhat.com> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.174.179.79] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To kwepemm600003.china.huawei.com (7.193.23.202) X-CFilter-Loop: Reflected X-Rspam-User: X-Stat-Signature: 7dimcrht11f9bntik9xspm3k5rse4xiw X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: 877A1C0017 X-HE-Tag: 1688644797-692129 X-HE-Meta: U2FsdGVkX1+Jg6c1e7m/W086E9BLTmpotUVe05RKP9vmzp2zc7xtxLQYcZ+5r6FWvyNwC29hPQ4+T7E7OhfNdu/NhJrY5pVdm2lFYa9+5y83MDUJhVc6d2e45VGY4n/WaXRJbN7SOnOG1CwQf5/1eMi0QNeyPhY0MKbxiIQ7nGrMwi+gw10Q0WUp36TDeI6/3lqhF5vj43Jh8xUNVGHkah9OtSZcc3EG/xFuhAtEQ/uWjO2P2xC+KYp7yhro3JAEyKau+loOA7LxBqs/O1M55v9RwQhNHGxnUafrDQm9qdmY7wpVX0hWowEBjN1Cy3rDYckwqZlnsnMDaUEiNTsDiLl6vdWL2F/Vgmkr9QB3suSYxyHoKKjZ5ZLOk73h2dKUMLM6vBbTrJ4ofMCNNrlf2Z4bg/pN1nQGvvM0HqzRSPqwkah49qKTu0jsTUQMWbG0vm3V264J0/OBCzrEZ55f7mPA4DZRdGVBRvi4/CL0dAorKzvj7q7Le2TpxOnT0VGi570VEAvb1RLv+8gwVOqZOftZwpNnZAS1d9chPSFOmi0wECXEAxnI7ryz1KeomhncBELRRknye+XxLBAxcfruZ9CBRK1eqW39f4JMrL0XgDSs2XXn9dXj6yISTNfYdRx+6elh6O12pgqPEErpjhiw4Y7/o9Q+CvtQ2U/zbqcrr0rPr/7BbHsQT9MGgZuSa7IHu8530W28RVXIXlQfoRTENpGRB87dj4RF41brPHTvO4Gsi9AHvyeHwRkd/S0mLfDFPj+ew7lLOF69L3jIM7txZtKtpJkQ38Pbis2iXPA8cYMdylWLefqWthBE18S83dCbZDdFHBD1VXDYy1OrZYry5iDCMtlZs2j6nIuPRR5/UoBXemyUL4RawkGE96nvyp8nEEvm0XWn4CEvEZIyX8/pHjpRW42/NsxP3/wIgM9A1X/LCarcK+3jL3hL6UC6GptuTNTcE2KJhfVUwTwYL3r jcwXAt1I hlPiG8BIfVggxjGI6e+nXoq9ag8k3z1Mb3WcXCr8tH1kw7TqiD2jOkgyzPVWoE4E/3Jez9Fl29QOywzvxBZNuh8vw8ZvIdlyblkOdLBTzim0IifsUP4JPy/7SkQEprgfPQSukynxEXOGNPQCDimTts0vxW6O3nGX1LRQBsrFThLc4BUq/5pkHm2iYo8EiQXirkOy9 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 2023/7/6 16:55, David Hildenbrand wrote: > On 06.07.23 11:49, Nanyong Sun wrote: >> Since the ksm_merging_pages information already included in >> /proc//ksm_stat, we could remove /proc//ksm_merging_pages >> to make the directory more clean, and can save a little bit resources. >> >> To delete this interface more smoothly and avoid userspace break, >> retain this interface temporarily and modify its function to hint >> users to use ksm_stat instead. >> >> Signed-off-by: Nanyong Sun >> --- >>   fs/proc/base.c | 9 +-------- >>   1 file changed, 1 insertion(+), 8 deletions(-) >> >> diff --git a/fs/proc/base.c b/fs/proc/base.c >> index eb2e498e3b8d..d080c58cbe6c 100644 >> --- a/fs/proc/base.c >> +++ b/fs/proc/base.c >> @@ -3189,14 +3189,7 @@ static int proc_pid_patch_state(struct >> seq_file *m, struct pid_namespace *ns, >>   static int proc_pid_ksm_merging_pages(struct seq_file *m, struct >> pid_namespace *ns, >>                   struct pid *pid, struct task_struct *task) >>   { >> -    struct mm_struct *mm; >> - >> -    mm = get_task_mm(task); >> -    if (mm) { >> -        seq_printf(m, "%lu\n", mm->ksm_merging_pages); >> -        mmput(mm); >> -    } >> - >> +    seq_puts(m, "please use /proc//ksm_stat instead\n"); >>       return 0; >>   } >>   static int proc_pid_ksm_stat(struct seq_file *m, struct >> pid_namespace *ns, > > > Why do we care so much about removing 15 simple LOC? That change here > will already mess with user space. > > Sorry, but IMHO it's all not worth the churn. > We do not pay attention to these 15 LOC. We pay more attention to the redundant interface under procfs. This interface is used by developers and has a short history. Therefore, changing it now has no big impact.