![]() ![]() I finally switched to using clock_gettime() and have much more believable results, but I am left wondering why the two system calls exist, and why they behave so differently. The only effect I have seen is that the non-zero values reported by getrusage() change from 1000us to a range of higher precision values centered about 1000us. I have tried enabling high res timers in the kernel and various combinations of VIRT_CPU_ACCOUNTING and/or VIRT_CPU_ACCOUNTING_GEN. When I implement tick() & tock() using clock_gettime(), I get values centered about 13us (with bizarre excursions to 75us or 100us occasionally, but I'll deal with later). When I implement tick() and tock() using getrusage(), I get mostly 0's out, and occasionally 1000us or 10000us values (according to whether I have configured my kernel. When I implement tick() and tock() using getrusage(), I get mostly 0's out, and occasionally 1000us or 10000us values (according to whether I have configured my kernel for 1kHz or 100Hz operation). The tick() function records the time at which it was run, the tock() function records the time at which it was run, computes the delta between the two, and reports that delta. The tick() function records the time at which it was run, the tock() function records the time at which it was run, computes the delta between the two, and reports that delta. EDIT: Since CPU is not straight forward to calculate, You could use sampling kind of stuff here. But all details will be in /proc/ PID /stat, so if we could parse it, we can get the percentage. As I have been digging into this, I have degenerated one part of my application to be: tick() getrusage () can help you in determining the usage of current process or its child Update: I cant remember an API. That application has an internal profiling capability implemented with tick() and tock() functions. There are two fields utime and stime in /proc//stat file, whose documentation says. Obviously, I'm asking because I see a difference between the two in an application I have ported to Linux (from a custom RTOS). I want to calculate CPU time consumption of a particular process in system mode and user mode using statistics present in /proc/.So, how does (thread specific) "user/system CPU time used" differ from a thread-specific CPU-time clock? deviation 3.86455 stime mean 0.000, deviation 0.0 utime mean 0.000, deviation 0.0 sleep. Struct timeval ru_stime /* system CPU time used */Īccording to the man page for clock_gettime(), it returns: CLOCK_THREAD_CPUTIME_ID (since Linux 2.6.12) Basic benchmarking of two programs using the time. According to the man page for getrusage(), it returns: struct timeval ru_utime /* user CPU time used */ Header('HTTP/1.0 500 Internal Server Error') ![]() $byteSize = $this->image->getImageSize() Have to workaround bugs in Imagick that return 0 for size by counting ourselves. $modifiedDate = gmdate('D, d M Y H:i:s'). getrusage (RUSAGETHREAD, ) calls taskcputimeadjusted (current, &utime, &stime), for which two definitions a, b exist which of them is used depends on the Linux kernel configuration item CONFIGVIRTCPUACCOUNTINGNATIVE: Select this option to enable more accurate task and CPU time accounting. Throw new ImThumbException("Could not set image headers, output already started", ImThumb::ERR_OUTPUTTING) three web servers (Apache, Nginx, Lighttpd) to measure the runtime performance of serving. Public function sendHeaders($serverErrorString = null) reconstruct a certain part of the trace (e.g., a limited time. Both tools (mkdosfs and dosfsck) have been unmaintained since some time. List($micro, $seconds) = split(" ", microtime()) Standard License Files > GNU General Public License, V2.0 > Apache License. List($micro, $seconds) = split(" ", $thold_start_rusage) This tutorial shows you how to use int64t. List($micro, $seconds) = explode(' ', microtime()) C (int64t)sec, (int64t)usec, Previous Next. List($micro, $seconds) = explode(' ', $thold_start_rusage) ![]() $i_s_time = $thold_start_rusage + $thold_start_rusage * 1.0E-6 $i_u_time = $thold_start_rusage + $thold_start_rusage * 1.0E-6 Print "ERROR: Can not display RUSAGE please call thold_initialize_rusage first" SEE ALSO clockgettime(2), getrlimit(2), times(2), wait(2), wait4(2), clock(3) This page is part of release 5.13 of the Linux man-pages project. (Since version 2.33, glibc no longer provides an vtimes () implementation.) See also the description of /proc/ pid/stat in proc(5). Html_start_box('', '100%', '', '3', 'left', '') All new applications should be written using getrusage (). ![]()
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