(PHP 4, PHP 5, PHP 7, PHP 8)

getrusageGets the current resource usages


getrusage(int $mode = 0): array|false

This is an interface to getrusage(2). It gets data returned from the system call.



If mode is 1, getrusage will be called with RUSAGE_CHILDREN.

Return Values

Returns an associative array containing the data returned from the system call. All entries are accessible by using their documented field names. Returns false on failure.


Version Description
7.0.0 This function is now supported on Windows.


Example #1 getrusage() example

= getrusage();
$dat["ru_oublock"]; // number of block output operations
echo $dat["ru_inblock"]; // number of block input operations
echo $dat["ru_msgsnd"]; // number of IPC messages sent
echo $dat["ru_msgrcv"]; // number of IPC messages received
echo $dat["ru_maxrss"]; // maximum resident set size
echo $dat["ru_ixrss"]; // integral shared memory size
echo $dat["ru_idrss"]; // integral unshared data size
echo $dat["ru_minflt"]; // number of page reclaims (soft page faults)
echo $dat["ru_majflt"]; // number of page faults (hard page faults)
echo $dat["ru_nsignals"]; // number of signals received
echo $dat["ru_nvcsw"]; // number of voluntary context switches
echo $dat["ru_nivcsw"]; // number of involuntary context switches
echo $dat["ru_nswap"]; // number of swaps
echo $dat["ru_utime.tv_usec"]; // user time used (microseconds)
echo $dat["ru_utime.tv_sec"]; // user time used (seconds)
echo $dat["ru_stime.tv_usec"]; // system time used (microseconds)
echo $dat["ru_stime.tv_sec"]; // system time used (seconds)



On Windows getrusage() will only return the following members:

  • "ru_stime.tv_sec"
  • "ru_stime.tv_usec"
  • "ru_utime.tv_sec"
  • "ru_utime.tv_usec"
  • "ru_majflt" (only if mode is RUSAGE_SELF)
  • "ru_maxrss" (only if mode is RUSAGE_SELF)

If getrusage() is called with mode set to 1 (RUSAGE_CHILDREN), then resource usage for threads are collected (meaning that internally the function is called with RUSAGE_THREAD).


on BeOS 2000, only the following members are returned:

  • "ru_stime.tv_sec"
  • "ru_stime.tv_usec"
  • "ru_utime.tv_sec"
  • "ru_utime.tv_usec"

See Also

  • Your system's man page on getrusage(2)

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User Contributed Notes 3 notes

jlh at gmx dot ch
7 years ago
Note that this function returns rusage of the current process. In a web environment where you have long running apache processes that serve several requests with PHP executions, this will return cumulative timings and is therefore not suitable for telling how much user time your used. The best you could do is to call getrusage() once at the beginning and once at the end and calculate the difference.
5 years ago
Domas Mituzas
16 years ago
getrusage() reports kernel counters that are updated only once application loses context and a switch to kernel space happens. For example on modern Linux server kernels that would mean that getrusage() calls would return information rounded at 10ms, desktop kernels - at 1ms.

getrusage() isn't usable for micro-measurements at all - and getmicrotime(true) might be much more valuable resource.
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