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Full Discussion: semaphore access speed
Top Forums Programming semaphore access speed Post 302239172 by jim mcnamara on Tuesday 23rd of September 2008 04:24:15 AM
Old 09-23-2008
Sorry - a little off track - I don't see where the OP has tried running ltrace with syscalls enabled - or strace.

The differences probably are due to OS implementation - maybe a lot of calls to brk in one OS and not the other. It's worth the 2 minutes it takes to execute Otheus' code under strace on each box. That would rule out an odd kernel setting or some implementation "feature" as the root cause of the differences. If you see odd behavior, like a lot of system calls on one box and not on the the other, maybe someone can relate that to something useful.
 

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STRACE-LOG-MERGE(1)					      General Commands Manual					       STRACE-LOG-MERGE(1)

NAME
strace-log-merge - merge strace -ff -tt output SYNOPSIS
strace-log-merge STRACE_LOG strace-log-merge --help DESCRIPTION
strace-log-merge merges the output of strace -ff -tt[t] command, prepending PID to each line and sorting the result using time stamp as a key. OPTIONS
--help Show program usage and exit. STRACE_LOG Output file name prefix of files produced by a strace -ff -tt[t] command. EXIT STATUS
0 Success Non-zero Error occurred: either no argument specified (in that case a usage is printed), or something went wrong during the processing of STRACE_LOG.* files. USAGE EXAMPLE
$ strace -o sleepy -ff -tt -e trace=execve,nanosleep sh -c 'sleep 0.1 & sleep 0.2 & sleep 0.3' $ strace-log-merge sleepy | fold -w 72 -s 13475 21:13:52.040837 execve("/bin/sh", ["sh", "-c", "sleep 0.1 & sleep 0.2 & sleep 0."...], 0x7ffde54b2450 /* 33 vars */) = 0 13478 21:13:52.044050 execve("/bin/sleep", ["sleep", "0.3"], 0x5631be4f87a8 /* 33 vars */) = 0 13476 21:13:52.044269 execve("/bin/sleep", ["sleep", "0.1"], 0x5631be4f87a8 /* 33 vars */) = 0 13477 21:13:52.044389 execve("/bin/sleep", ["sleep", "0.2"], 0x5631be4f87a8 /* 33 vars */) = 0 13478 21:13:52.046207 nanosleep({tv_sec=0, tv_nsec=300000000}, NULL) = 0 13476 21:13:52.046303 nanosleep({tv_sec=0, tv_nsec=100000000}, NULL) = 0 13477 21:13:52.046318 nanosleep({tv_sec=0, tv_nsec=200000000}, NULL) = 0 13476 21:13:52.146852 +++ exited with 0 +++ 13475 21:13:52.146942 --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=13476, si_uid=1000, si_status=0, si_utime=0, si_stime=0} --- 13477 21:13:52.247782 +++ exited with 0 +++ 13475 21:13:52.247885 --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=13477, si_uid=1000, si_status=0, si_utime=0, si_stime=0} --- 13478 21:13:52.347680 +++ exited with 0 +++ 13475 21:13:52.347786 --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=13478, si_uid=1000, si_status=0, si_utime=0, si_stime=0} --- 13475 21:13:52.348069 +++ exited with 0 +++ NOTES
strace-log-merge does not work well with strace logs generated by strace -tt invocation that pass midnight, as those lack the information required for the proper sorting. Employing the -ttt option in the respective strace invocation should solve the problem. BUGS
strace-log-merge does not perform any checks whether the files specified are in the correct format and implies that only files from a sin- gle strace session match STRACE_LOG.* glob pattern. HISTORY
The initial version of strace-log-merge was written by Denys Vlasenko in 2012. REPORTING BUGS
Problems with strace-log-merge should be reported to the strace mailing list at <strace-devel@lists.sourceforge.net>. SEE ALSO
strace(1) strace UNKNOWN 2018-04-11 STRACE-LOG-MERGE(1)
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