* + proc-replace-seq_printf-by-seq_put_smth-to-speed-up-proc-pid-status.patch added to -mm tree
@ 2018-02-16 23:51 akpm
0 siblings, 0 replies; only message in thread
From: akpm @ 2018-02-16 23:51 UTC (permalink / raw)
To: avagin, adobriyan, kamezawa.hiroyu, mm-commits
The patch titled
Subject: proc: replace seq_printf by seq_put_smth to speed up /proc/pid/status
has been added to the -mm tree. Its filename is
proc-replace-seq_printf-by-seq_put_smth-to-speed-up-proc-pid-status.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/proc-replace-seq_printf-by-seq_put_smth-to-speed-up-proc-pid-status.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/proc-replace-seq_printf-by-seq_put_smth-to-speed-up-proc-pid-status.patch
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*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Andrei Vagin <avagin@openvz.org>
Subject: proc: replace seq_printf by seq_put_smth to speed up /proc/pid/status
seq_printf() works slower than seq_puts, seq_puts, etc.
== test_proc.c
int main(int argc, char **argv)
{
int n, i, fd;
char buf[16384];
n = atoi(argv[1]);
for (i = 0; i < n; i++) {
fd = open(argv[2], O_RDONLY);
if (fd < 0)
return 1;
if (read(fd, buf, sizeof(buf)) <= 0)
return 1;
close(fd);
}
return 0;
}
==
$ time ./test_proc 1000000 /proc/1/status
== Before path ==
real 0m5.171s
user 0m0.328s
sys 0m4.783s
== After patch ==
real 0m4.761s
user 0m0.334s
sys 0m4.366s
Link: http://lkml.kernel.org/r/20180212074931.7227-4-avagin@openvz.org
Signed-off-by: Andrei Vagin <avagin@openvz.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
fs/proc/array.c | 16 +++++++++++-----
1 file changed, 11 insertions(+), 5 deletions(-)
diff -puN fs/proc/array.c~proc-replace-seq_printf-by-seq_put_smth-to-speed-up-proc-pid-status fs/proc/array.c
--- a/fs/proc/array.c~proc-replace-seq_printf-by-seq_put_smth-to-speed-up-proc-pid-status
+++ a/fs/proc/array.c
@@ -174,7 +174,8 @@ static inline void task_state(struct seq
if (umask >= 0)
seq_printf(m, "Umask:\t%#04o\n", umask);
- seq_printf(m, "State:\t%s", get_task_state(p));
+ seq_puts(m, "State:\t");
+ seq_puts(m, get_task_state(p));
seq_put_decimal_ull(m, "\nTgid:\t", tgid);
seq_put_decimal_ull(m, "\nNgid:\t", ngid);
@@ -300,8 +301,8 @@ static void render_cap_t(struct seq_file
seq_puts(m, header);
CAP_FOR_EACH_U32(__capi) {
- seq_printf(m, "%08x",
- a->cap[CAP_LAST_U32 - __capi]);
+ seq_put_hex_ll(m, NULL,
+ a->cap[CAP_LAST_U32 - __capi], 8);
}
seq_putc(m, '\n');
}
@@ -355,7 +356,8 @@ static void task_cpus_allowed(struct seq
static inline void task_core_dumping(struct seq_file *m, struct mm_struct *mm)
{
- seq_printf(m, "CoreDumping:\t%d\n", !!mm->core_state);
+ seq_put_decimal_ull(m, "CoreDumping:\t", !!mm->core_state);
+ seq_putc(m, '\n');
}
int proc_pid_status(struct seq_file *m, struct pid_namespace *ns,
@@ -491,7 +493,11 @@ static int do_task_stat(struct seq_file
/* convert nsec -> ticks */
start_time = nsec_to_clock_t(task->real_start_time);
- seq_printf(m, "%d (%s) %c", pid_nr_ns(pid, ns), tcomm, state);
+ seq_put_decimal_ull(m, "", pid_nr_ns(pid, ns));
+ seq_puts(m, " (");
+ seq_puts(m, tcomm);
+ seq_puts(m, ") ");
+ seq_putc(m, state);
seq_put_decimal_ll(m, " ", ppid);
seq_put_decimal_ll(m, " ", pgid);
seq_put_decimal_ll(m, " ", sid);
_
Patches currently in -mm which might be from avagin@openvz.org are
procfs-add-seq_put_hex_ll-to-speed-up-proc-pid-maps.patch
procfs-add-seq_put_hex_ll-to-speed-up-proc-pid-maps-v3.patch
procfs-optimize-seq_pad-to-speed-up-proc-pid-maps.patch
proc-add-seq_put_decimal_ull_width-to-speed-up-proc-pid-smaps.patch
proc-replace-seq_printf-on-seq_putc-to-speed-up-proc-pid-smaps.patch
proc-optimize-single-symbol-delimiters-to-spead-up-seq_put_decimal_ull.patch
proc-replace-seq_printf-by-seq_put_smth-to-speed-up-proc-pid-status.patch
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2018-02-16 23:51 + proc-replace-seq_printf-by-seq_put_smth-to-speed-up-proc-pid-status.patch added to -mm tree akpm
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