OSLAT(8)                    System Manager's Manual                   OSLAT(8)

NAME
       oslat - OS Latency Detector

SYNOPSIS
       oslat [ -shvz ] [ -b bucket-size ] [ -B bias ] [ -c cpu-list ] [ -C
             cpu-main-thread ] [ -f rt-prio ] [ --json filename ] [ -m
             workload-mem ] [-t runtime ] [ -T trace-threshold ] [ -w workload
             ] [ -W bucket-width ]

DESCRIPTION
       oslat is an open source userspace polling mode stress program to detect
       OS level latency.  The program runs a busy loop with no or various
       workloads, collecting TSC information and measuring the time frequently
       during the process.

OPTIONS
       -b, --bucket-size=N
              Specify the number of the buckets (4-1024).

       -B, --bias
              Add a bias to all the buckets using the estimated mininum.

       -c, --cpu-list=CPULIST
              Specify CPUs to run on.  For example, '1,3,5,7-15'.

       -C, --cpu-main-thread=CORE
              Specify which CPU the main thread runs on.  Default is cpu0.

       -f, --rtprio=PRIORITY
              Using specific SCHED_FIFO priority (1-99).  Otherwise use the
              default priority, normally it will be SCHED_OTHER.

       --json=FILENAME
              Write final results into FILENAME, JSON formatted.

       -m, --workload-mem=SIZE
              Size of the memory to use for the workload (e.g., 4K, 1M).
              Total memory usage will be this value multiplies 2*N, because
              there will be src/dst buffers for each thread, and N is the
              number of processors for testing.

       -D, --duration=TIME
              Specify test duration, e.g., 60, 20m, 2H (m/M: minutes, h/H:
              hours, d/D: days).  By default the unit is s/second.

       -T, --trace-threshold=THRESHOLD
              Stop the test when threshold triggered (in USEC).  At the
              meantime, print a marker in ftrace and stop ftrace too.

       -w, --workload=WORKLOAD
              Specify a kind of workload, default is no workload.  Options:
              "no", "memmove".

       -s, --single-preheat
              Use a single thread when measuring latency at preheat stage
              NOTE: please make sure the CPU frequency on all testing cores
              are locked before using this parmater.  If you don't know how to
              lock the freq then please don't use this parameter.

       -W, --bucket-width
              Interval between buckets in nanoseconds

              NOTE: Widths not a multiple of 1000 cause ns-precision output
              You are responsible for considering the impact of measurement
              overhead at the nanosecond scale.

       -h, --help
              Show the help message.

       -v, --version
              Show the version of the program.

       -z, --zero-omit
              Don't display buckets in the output histogram if all zeros.

AUTHOR
       oslat was written by Peter Xu <peterx@redhat.com>.

                                August 17, 2020                       OSLAT(8)