FreeBSD Manual Pages
LAT_SYSCALL(8) LMBENCH LAT_SYSCALL(8) NAME lat_syscall - time simple entry into the operating system SYNOPSIS lat_syscall [ -P _parallelism_ ] [ -W _warmups_ ] [ -N _repetitions_ ] null|read|write|stat|fstat|open [ file ] DESCRIPTION null measures how long it takes to do getppid(). We chose getppid() because in all UNIX variants we are aware of, it requires a round-trip to/from kernel space and the actual work required in- side the kernel is small and bounded. read measures how long it takes to read one byte from /dev/zero. Note that some operating systems do not support /dev/zero. write times how long it takes to write one byte to /dev/null. This is useful as a lower bound cost on anything that has to interact with the operating system. stat measures how long it takes to stat() a file whose inode is al- ready cached. fstat measures how long it takes to fstat() an open file whose inode is already cached. open measures how long it takes to open() and then close() a file. OUTPUT Output format is Null syscall: 67 microseconds ACKNOWLEDGEMENT Funding for the development of this tool was provided by Sun Microsys- tems Computer Corporation. SEE ALSO lmbench(8). AUTHOR Carl Staelin and Larry McVoy Comments, suggestions, and bug reports are always welcome. (c)1994 Larry McVoy $Date$ LAT_SYSCALL(8)
NAME | SYNOPSIS | DESCRIPTION | OUTPUT | ACKNOWLEDGEMENT | SEE ALSO | AUTHOR
Want to link to this manual page? Use this URL:
<https://www.freebsd.org/cgi/man.cgi?query=lat_syscall&sektion=8&manpath=FreeBSD+12.1-RELEASE+and+Ports>