Bug #72322 [NoF->ReO]: High sys CPU usage

From: Date: Sun, 25 Dec 2016 10:45:39 +0000
Subject: Bug #72322 [NoF->ReO]: High sys CPU usage
References: 1  Groups: php.bugs 
Request: Send a blank email to php-bugs+get-206196@lists.php.net to get a copy of this message
Edit report at https://bugs.php.net/bug.php?id=72322&edit=1

 ID:                 72322
 Updated by:         nikic@php.net
 Reported by:        jai at vidyamantra dot com
 Summary:            High sys CPU usage
-Status:             No Feedback
+Status:             Re-Opened
 Type:               Bug
 Package:            Performance problem
 Operating System:   Centos 6.8 x64
 PHP Version:        7.0.7
 Block user comment: N
 Private report:     N



Previous Comments:
------------------------------------------------------------------------
[2016-12-25 04:22:19] php-bugs at lists dot php dot net

No feedback was provided. The bug is being suspended because
we assume that you are no longer experiencing the problem.
If this is not the case and you are able to provide the
information that was requested earlier, please do so and
change the status of the bug back to "Re-Opened". Thank you.

------------------------------------------------------------------------
[2016-12-20 07:33:31] jai at vidyamantra dot com

Tested on version 7.0.10 and problem is still present. It happens more often when system memory is
near full (swap still empty), for e.g. system has 256GB of RAM and this happens when about only 10GB
of RAM is used. At this stage, sys time increase significantly.

------------------------------------------------------------------------
[2016-12-17 14:51:26] nikic@php.net

Do you still experience this problem with a current version of PHP 7? I'd assume the issue is
due to huge pages (see https://bugs.php.net/bug.php?id=70984), which are
no longer enabled by default.

------------------------------------------------------------------------
[2016-06-03 06:58:47] jai at vidyamantra dot com

Description:
------------
Upgrade to php 7 and saw high CPU usage.
http://serverfault.com/q/780555/126826 (CPU
graphs and sar output).

==== PHP 7 ====
% time     seconds  usecs/call     calls    errors syscall
------ ----------- ----------- --------- --------- ----------------
 31.24    0.000973           1      1204           munmap
 15.25    0.000475           0      1523         3 open
 12.52    0.000390           0      4012       216 lstat
  7.70    0.000240           0      1363           mmap
  5.81    0.000181           0      1528           close
  5.36    0.000167           1       219           getdents
  5.01    0.000156           0      1618           stat
  4.33    0.000135           0      1433       535 access
  3.69    0.000115           0      3256           fstat
  2.47    0.000077           0       547           write
  1.67    0.000052           0       224           uname
  1.22    0.000038           0       276           sendto
  0.87    0.000027           0       638           read
  0.83    0.000026           0       752           flock
  0.58    0.000018           0       760           poll

==== PHP 5 ====
% time     seconds  usecs/call     calls    errors syscall
------ ----------- ----------- --------- --------- ----------------
 23.32    0.001103           5       206           sendto
 17.45    0.000825           1      1650           getdents
 14.95    0.000707           0      4638       651 stat
 10.59    0.000501           0      3181      1708 access
  7.27    0.000344           0      4918       172 lstat
  6.07    0.000287           0      2391         3 open
  4.76    0.000225           1       314           poll
  3.66    0.000173           0      1526           munmap
  2.56    0.000121           0      4633           fstat
  2.11    0.000100           0      1704           mmap
  1.54    0.000073           1        97           rename
  1.40    0.000066           0       923         2 lseek
  1.08    0.000051           0      2395           close
  0.80    0.000038           0       562        49 ioctl
  0.68    0.000032           0       831           read
  0.57    0.000027           0       406           write
  0.34    0.000016           0       141           mprotect



------------------------------------------------------------------------



--
Edit this bug report at https://bugs.php.net/bug.php?id=72322&edit=1


Thread (11 messages)

« previous php.bugs (#206196) next »