Edit File: rwtime-nd.8
.TH rwtime-nd 8 "2015-01-30" "USER COMMANDS" .SH NAME rwtime-nd \- summarize syscall read() and write() times. Uses Linux SystemTap (non-debuginfo). .SH SYNOPSIS .B rwtime-nd.stp [execname] .SH DESCRIPTION This traces read() and write() syscalls, producing a histogram summary of their durations (aka latencies). .SH REQUIREMENTS SystemTap. .SH OPTIONS .TP execname An optional argument to specify the process name to trace. All PIDs with this process name will be observed. .SH EXAMPLES .TP Trace all syscall read()s and write()s, showing latency summaries: # .B rwtime-nd.stp .TP Trace all syscall read()s and write()s for processes named "node": .B rwtime-nd.stp node .SH OVERHEAD While these syscalls are frequent, the overhead should be low as this uses in-kernel summaries. Test before use to confirm. .SH SOURCE This is from the SystemTap lwtools collection. .IP https://github.com/brendangregg/systemtap-lwtools .PP Also look under the examples directory for a text file containing example usage, output, and commentary for this tool. .SH OS Linux .SH STABILITY Unstable - in development. .SH AUTHOR Brendan Gregg .SH SEE ALSO strace(1)