From: Alexey Dobriyan <adobriyan@gmail.com>
To: akpm@linux-foundation.org
Cc: linux-kernel@vger.kernel.org, Alexey Dobriyan <adobriyan@gmail.com>
Subject: [PATCH 10/13] proc: convert readdir /proc to _print_integer()
Date: Tue, 28 Aug 2018 02:15:00 +0300 [thread overview]
Message-ID: <20180827231503.26899-10-adobriyan@gmail.com> (raw)
In-Reply-To: <20180827231503.26899-1-adobriyan@gmail.com>
Benchmark readdir("/proc") 2^13 times with 2K processes in a pid
namespace:
850.3750 us per readdir
786.5625
-7.5%
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
---
fs/proc/base.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 79d2f7d72ad1..33f444721965 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -3223,16 +3223,15 @@ int proc_pid_readdir(struct file *file, struct dir_context *ctx)
for (iter = next_tgid(ns, iter);
iter.task;
iter.tgid += 1, iter = next_tgid(ns, iter)) {
- char name[10 + 1];
- unsigned int len;
+ char name[10], *p = name + sizeof(name);
cond_resched();
if (!has_pid_permissions(ns, iter.task, HIDEPID_INVISIBLE))
continue;
- len = snprintf(name, sizeof(name), "%u", iter.tgid);
+ p = _print_integer_u32(p, iter.tgid);
ctx->pos = iter.tgid + TGID_OFFSET;
- if (!proc_fill_cache(file, ctx, name, len,
+ if (!proc_fill_cache(file, ctx, p, name + sizeof(name) - p,
proc_pid_instantiate, iter.task, NULL)) {
put_task_struct(iter.task);
return 0;
--
2.16.4
next prev parent reply other threads:[~2018-08-27 23:16 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 ` Alexey Dobriyan [this message]
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 ` [PATCH 13/13] proc: convert /proc/*/task/*/children " Alexey Dobriyan
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
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20180827231503.26899-10-adobriyan@gmail.com \
--to=adobriyan@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=linux-kernel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).