The patch titled
Subject: procfs: speed up /proc/pid/stat, statm
has been added to the -mm tree. Its filename is
procfs-speed-up-proc-pid-stat-statm.patch
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From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Subject: procfs: speed up /proc/pid/stat, statm
Process accounting applications as top, ps visit some files under
/proc/<pid>. With seq_put_decimal_ull(), we can optimize /proc/<pid>/stat
and /proc/<pid>/statm files.
This patch adds
- seq_put_decimal_ll() for signed values.
- allow delimiter == 0.
- convert seq_printf() to seq_put_decimal_ull/ll in /proc/stat, statm.
Test result on a system with 2000+ procs.
Before patch:
[kamezawa@bluextal test]$ top -b -n 1 | wc -l
2223
[kamezawa@bluextal test]$ time top -b -n 1 > /dev/null
real 0m0.675s
user 0m0.044s
sys 0m0.121s
[kamezawa@bluextal test]$ time ps -elf > /dev/null
real 0m0.236s
user 0m0.056s
sys 0m0.176s
After patch:
kamezawa@bluextal ~]$ time top -b -n 1 > /dev/null
real 0m0.657s
user 0m0.052s
sys 0m0.100s
[kamezawa@bluextal ~]$ time ps -elf > /dev/null
real 0m0.198s
user 0m0.050s
sys 0m0.145s
Considering top, ps tend to scan /proc periodically, this will reduce cpu
consumption by top/ps to some extent.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Cc: Alexey Dobriyan <adobriyan@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/proc/array.c | 119 +++++++++++++++++++------------------
fs/seq_file.c | 21 ++++++
include/linux/seq_file.h | 2
3 files changed, 86 insertions(+), 56 deletions(-)
diff -puN fs/proc/array.c~procfs-speed-up-proc-pid-stat-statm fs/proc/array.c
--- a/fs/proc/array.c~procfs-speed-up-proc-pid-stat-statm
+++ a/fs/proc/array.c
@@ -462,59 +462,56 @@ static int do_task_stat(struct seq_file
/* convert nsec -> ticks */
start_time = nsec_to_clock_t(start_time);
- seq_printf(m, "%d (%s) %c %d %d %d %d %d %u %lu \
-%lu %lu %lu %lu %lu %ld %ld %ld %ld %d 0 %llu %lu %ld %lu %lu %lu %lu %lu \
-%lu %lu %lu %lu %lu %lu %lu %lu %d %d %u %u %llu %lu %ld %lu %lu %lu\n",
- pid_nr_ns(pid, ns),
- tcomm,
- state,
- ppid,
- pgid,
- sid,
- tty_nr,
- tty_pgrp,
- task->flags,
- min_flt,
- cmin_flt,
- maj_flt,
- cmaj_flt,
- cputime_to_clock_t(utime),
- cputime_to_clock_t(stime),
- cputime_to_clock_t(cutime),
- cputime_to_clock_t(cstime),
- priority,
- nice,
- num_threads,
- start_time,
- vsize,
- mm ? get_mm_rss(mm) : 0,
- rsslim,
- mm ? (permitted ? mm->start_code : 1) : 0,
- mm ? (permitted ? mm->end_code : 1) : 0,
- (permitted && mm) ? mm->start_stack : 0,
- esp,
- eip,
- /* The signal information here is obsolete.
- * It must be decimal for Linux 2.0 compatibility.
- * Use /proc/#/status for real-time signals.
- */
- task->pending.signal.sig[0] & 0x7fffffffUL,
- task->blocked.sig[0] & 0x7fffffffUL,
- sigign .sig[0] & 0x7fffffffUL,
- sigcatch .sig[0] & 0x7fffffffUL,
- wchan,
- 0UL,
- 0UL,
- task->exit_signal,
- task_cpu(task),
- task->rt_priority,
- task->policy,
- (unsigned long long)delayacct_blkio_ticks(task),
- cputime_to_clock_t(gtime),
- cputime_to_clock_t(cgtime),
- (mm && permitted) ? mm->start_data : 0,
- (mm && permitted) ? mm->end_data : 0,
- (mm && permitted) ? mm->start_brk : 0);
+ seq_printf(m,"%d (%s) %c", pid_nr_ns(pid, ns), tcomm, state);
+ seq_put_decimal_ll(m, ' ', ppid);
+ seq_put_decimal_ll(m, ' ', pgid);
+ seq_put_decimal_ll(m, ' ', sid);
+ seq_put_decimal_ll(m, ' ', tty_nr);
+ seq_put_decimal_ll(m, ' ', tty_pgrp);
+ seq_put_decimal_ull(m, ' ', task->flags);
+ seq_put_decimal_ull(m, ' ', min_flt);
+ seq_put_decimal_ull(m, ' ', cmin_flt);
+ seq_put_decimal_ull(m, ' ', maj_flt);
+ seq_put_decimal_ull(m, ' ', cmaj_flt);
+ seq_put_decimal_ull(m, ' ', cputime_to_clock_t(utime));
+ seq_put_decimal_ull(m, ' ', cputime_to_clock_t(stime));
+ seq_put_decimal_ll(m, ' ', cputime_to_clock_t(cutime));
+ seq_put_decimal_ll(m, ' ', cputime_to_clock_t(cstime));
+ seq_put_decimal_ll(m, ' ', priority);
+ seq_put_decimal_ll(m, ' ', nice);
+ seq_put_decimal_ll(m, ' ', num_threads);
+ seq_put_decimal_ull(m, ' ', 0);
+ seq_put_decimal_ull(m, ' ', start_time);
+ seq_put_decimal_ull(m, ' ', vsize);
+ seq_put_decimal_ll(m, ' ', mm ? get_mm_rss(mm) : 0);
+ seq_put_decimal_ull(m, ' ', rsslim);
+ seq_put_decimal_ull(m, ' ', mm ? (permitted ? mm->start_code : 1) : 0);
+ seq_put_decimal_ull(m, ' ', mm ? (permitted ? mm->end_code : 1) : 0);
+ seq_put_decimal_ull(m, ' ', (permitted && mm) ? mm->start_stack : 0);
+ seq_put_decimal_ull(m, ' ', esp);
+ seq_put_decimal_ull(m, ' ', eip);
+ /* The signal information here is obsolete.
+ * It must be decimal for Linux 2.0 compatibility.
+ * Use /proc/#/status for real-time signals.
+ */
+ seq_put_decimal_ull(m, ' ', task->pending.signal.sig[0] & 0x7fffffffUL);
+ seq_put_decimal_ull(m, ' ', task->blocked.sig[0] & 0x7fffffffUL);
+ seq_put_decimal_ull(m, ' ', sigign.sig[0] & 0x7fffffffUL);
+ seq_put_decimal_ull(m, ' ', sigcatch.sig[0] & 0x7fffffffUL);
+ seq_put_decimal_ull(m, ' ', wchan);
+ seq_put_decimal_ull(m, ' ', 0);
+ seq_put_decimal_ull(m, ' ', 0);
+ seq_put_decimal_ll(m, ' ', task->exit_signal);
+ seq_put_decimal_ll(m, ' ', task_cpu(task));
+ seq_put_decimal_ull(m, ' ', task->rt_priority);
+ seq_put_decimal_ull(m, ' ', task->policy);
+ seq_put_decimal_ull(m, ' ', delayacct_blkio_ticks(task));
+ seq_put_decimal_ull(m, ' ', cputime_to_clock_t(gtime));
+ seq_put_decimal_ll(m, ' ', cputime_to_clock_t(cgtime));
+ seq_put_decimal_ull(m, ' ', (mm && permitted) ? mm->start_data : 0);
+ seq_put_decimal_ull(m, ' ', (mm && permitted) ? mm->end_data : 0);
+ seq_put_decimal_ull(m, ' ', (mm && permitted) ? mm->start_brk : 0);
+ seq_putc(m, '\n');
if (mm)
mmput(mm);
return 0;
@@ -542,8 +539,20 @@ int proc_pid_statm(struct seq_file *m, s
size = task_statm(mm, &shared, &text, &data, &resident);
mmput(mm);
}
- seq_printf(m, "%lu %lu %lu %lu 0 %lu 0\n",
- size, resident, shared, text, data);
+ /*
+ * For quick read, open code by putting numbers directly
+ * expected format is
+ * seq_printf(m, "%lu %lu %lu %lu 0 %lu 0\n",
+ * size, resident, shared, text, data);
+ */
+ seq_put_decimal_ull(m, 0, size);
+ seq_put_decimal_ull(m, ' ', resident);
+ seq_put_decimal_ull(m, ' ', shared);
+ seq_put_decimal_ull(m, ' ', text);
+ seq_put_decimal_ull(m, ' ', 0);
+ seq_put_decimal_ull(m, ' ', text);
+ seq_put_decimal_ull(m, ' ', 0);
+ seq_putc(m, '\n');
return 0;
}
diff -puN fs/seq_file.c~procfs-speed-up-proc-pid-stat-statm fs/seq_file.c
--- a/fs/seq_file.c~procfs-speed-up-proc-pid-stat-statm
+++ a/fs/seq_file.c
@@ -659,7 +659,8 @@ int seq_put_decimal_ull(struct seq_file
if (m->count + 2 >= m->size) /* we'll write 2 bytes at least */
goto overflow;
- m->buf[m->count++] = delimiter;
+ if (delimiter)
+ m->buf[m->count++] = delimiter;
if (num < 10) {
m->buf[m->count++] = num + '0';
@@ -677,6 +678,24 @@ overflow:
}
EXPORT_SYMBOL(seq_put_decimal_ull);
+int seq_put_decimal_ll(struct seq_file *m, char delimiter,
+ long long num)
+{
+ if (num < 0) {
+ if (m->count + 3 >= m->size) {
+ m->count = m->size;
+ return -1;
+ }
+ if (delimiter)
+ m->buf[m->count++] = delimiter;
+ num = -num;
+ delimiter = '-';
+ }
+ return seq_put_decimal_ull(m, delimiter, num);
+
+}
+EXPORT_SYMBOL(seq_put_decimal_ll);
+
/**
* seq_write - write arbitrary data to buffer
* @seq: seq_file identifying the buffer to which data should be written
diff -puN include/linux/seq_file.h~procfs-speed-up-proc-pid-stat-statm include/linux/seq_file.h
--- a/include/linux/seq_file.h~procfs-speed-up-proc-pid-stat-statm
+++ a/include/linux/seq_file.h
@@ -123,6 +123,8 @@ int seq_open_private(struct file *, cons
int seq_release_private(struct inode *, struct file *);
int seq_put_decimal_ull(struct seq_file *m, char delimiter,
unsigned long long num);
+int seq_put_decimal_ll(struct seq_file *m, char delimiter,
+ long long num);
#define SEQ_START_TOKEN ((void *)1)
/*
_
Subject: Subject: procfs: speed up /proc/pid/stat, statm
Patches currently in -mm which might be from kamezawa.hiroyu@xxxxxxxxxxxxxx are
origin.patch
mm-postpone-migrated-page-mapping-reset.patch
linux-next.patch
mm-memcontrolc-fix-warning-with-config_numa=n.patch
mm-oom-avoid-looping-when-chosen-thread-detaches-its-mm.patch
mm-oom-fold-oom_kill_task-into-oom_kill_process.patch
mm-oom-do-not-emit-oom-killer-warning-if-chosen-thread-is-already-exiting.patch
mm-add-rss-counters-consistency-check.patch
mm-vmscanc-cleanup-with-s-reclaim_mode-isolate_mode.patch
mm-make-get_mm_counter-static-inline.patch
mm-vmscan-fix-misused-nr_reclaimed-in-shrink_mem_cgroup_zone.patch
memcg-replace-mem_cont-by-mem_res_ctlr.patch
memcg-replace-mem-and-mem_cont-stragglers.patch
memcg-lru_size-instead-of-mem_cgroup_zstat.patch
memcg-enum-lru_list-lru.patch
memcg-remove-redundant-returns.patch
memcg-remove-unnecessary-thp-check-in-page-stat-accounting.patch
idr-make-idr_get_next-good-for-rcu_read_lock.patch
cgroup-revert-ss_id_lock-to-spinlock.patch
memcg-let-css_get_next-rely-upon-rcu_read_lock.patch
memcg-remove-pcg_cache-page_cgroup-flag.patch
memcg-remove-pcg_cache-page_cgroup-flag-checkpatch-fixes.patch
proc-speedup-proc-stat-handling.patch
procfs-add-num_to_str-to-speed-up-proc-stat.patch
procfs-add-num_to_str-to-speed-up-proc-stat-fix.patch
procfs-speed-up-proc-pid-stat-statm.patch
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