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From: Alexey Dobriyan <adobriyan@gmail.com>
To: akpm@linux-foundation.org
Cc: linux-kernel@vger.kernel.org, Alexey Dobriyan <adobriyan@gmail.com>
Subject: [PATCH 13/13] proc: convert /proc/*/task/*/children to _print_integer()
Date: Tue, 28 Aug 2018 02:15:03 +0300	[thread overview]
Message-ID: <20180827231503.26899-13-adobriyan@gmail.com> (raw)
In-Reply-To: <20180827231503.26899-1-adobriyan@gmail.com>

Benchmark pread /proc/1/task/1/children 2^21 times on the same system:

	6.766400479 s
	4.328648442

	-36%

(need to remeasure on a controlled set of children)

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
---
 fs/proc/array.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/fs/proc/array.c b/fs/proc/array.c
index d0565527166a..045ce2cac1dd 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -710,9 +710,11 @@ get_children_pid(struct inode *inode, struct pid *pid_prev, loff_t pos)
 static int children_seq_show(struct seq_file *seq, void *v)
 {
 	struct inode *inode = file_inode(seq->file);
+	char buf[10 + 1], *p = buf + sizeof(buf);
 
-	seq_printf(seq, "%d ", pid_nr_ns(v, proc_pid_ns(inode)));
-	return 0;
+	*--p = ' ';
+	p = _print_integer_u32(p, pid_nr_ns(v, proc_pid_ns(inode)));
+	return seq_write(seq, p, buf + sizeof(buf) - p);
 }
 
 static void *children_seq_start(struct seq_file *seq, loff_t *pos)
-- 
2.16.4


  parent reply	other threads:[~2018-08-27 23:15 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-08-27 23:14 [PATCH 01/13] seq_file: rewrite seq_puts() in terms of seq_write() Alexey Dobriyan
2018-08-27 23:14 ` [PATCH 02/13] proc: apply seq_puts() whenever possible Alexey Dobriyan
2018-08-27 23:14 ` [PATCH 03/13] proc: rename "p" variable in proc_readfd_common() Alexey Dobriyan
2018-08-27 23:14 ` [PATCH 04/13] proc: rename "p" variable in proc_map_files_readdir() Alexey Dobriyan
2018-08-27 23:14 ` [PATCH 05/13] proc: new and improved way to print decimals Alexey Dobriyan
2018-08-27 23:14 ` [PATCH 06/13] proc: convert /proc/self to _print_integer() Alexey Dobriyan
2018-08-29  9:50   ` David Laight
2018-08-30 13:13     ` Alexey Dobriyan
2018-08-27 23:14 ` [PATCH 07/13] proc: convert /proc/thread-self " Alexey Dobriyan
2018-08-27 23:14 ` [PATCH 08/13] proc: convert /proc/*/fd " Alexey Dobriyan
2018-08-27 23:14 ` [PATCH 09/13] proc: convert dentry flushing on exit " Alexey Dobriyan
2018-08-27 23:15 ` [PATCH 10/13] proc: convert readdir /proc " Alexey Dobriyan
2018-08-27 23:15 ` [PATCH 11/13] proc: readdir /proc/*/task Alexey Dobriyan
2018-08-28 12:36   ` Ahmed S. Darwish
2018-08-28 13:04     ` Ahmed S. Darwish
2018-08-28 19:35       ` Alexey Dobriyan
2018-08-29 23:43         ` Andrew Morton
2018-08-30 13:20           ` Alexey Dobriyan
2018-08-28 19:31     ` Alexey Dobriyan
2018-08-27 23:15 ` [PATCH 12/13] proc: convert /proc/*/statm to _print_integer() Alexey Dobriyan
2018-08-27 23:15 ` Alexey Dobriyan [this message]
2018-08-28 18:24 ` [PATCH 01/13] seq_file: rewrite seq_puts() in terms of seq_write() Joe Perches
2018-08-28 20:48   ` Joe Perches
2018-09-03 14:17 ` Alexey Dobriyan

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