From: Vincent Fu Date: Thu, 9 Jan 2020 16:15:00 +0000 (-0500) Subject: docs: updates for slat, clat, lat percentile reporting X-Git-Tag: fio-3.18~1^2~6 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=dd39b9cec30fd0540f62aef9db8cb2b565b0a8e6;p=fio.git docs: updates for slat, clat, lat percentile reporting Modify the HOWTO and man page to reflect changes to the slat, clat, and lat percentile reporting options. Signed-off-by: Vincent Fu --- diff --git a/HOWTO b/HOWTO index f19f9226..d7634790 100644 --- a/HOWTO +++ b/HOWTO @@ -3346,27 +3346,28 @@ Measurements and reporting Disable measurements of throughput/bandwidth numbers. See :option:`disable_lat`. +.. option:: slat_percentiles=bool + + Report submission latency percentiles. Submission latency is not recorded + for synchronous ioengines. + .. option:: clat_percentiles=bool - Enable the reporting of percentiles of completion latencies. This - option is mutually exclusive with :option:`lat_percentiles`. + Report completion latency percentiles. .. option:: lat_percentiles=bool - Enable the reporting of percentiles of I/O latencies. This is similar - to :option:`clat_percentiles`, except that this includes the - submission latency. This option is mutually exclusive with - :option:`clat_percentiles`. + Report total latency percentiles. Total latency is the sum of submission + latency and completion latency. .. option:: percentile_list=float_list - Overwrite the default list of percentiles for completion latencies and - the block error histogram. Each number is a floating number in the - range (0,100], and the maximum length of the list is 20. Use ``:`` to - separate the numbers, and list the numbers in ascending order. For + Overwrite the default list of percentiles for latencies and the block error + histogram. Each number is a floating point number in the range (0,100], and + the maximum length of the list is 20. Use ``:`` to separate the numbers. For example, ``--percentile_list=99.5:99.9`` will cause fio to report the - values of completion latency below which 99.5% and 99.9% of the observed - latencies fell, respectively. + latency durations below which 99.5% and 99.9% of the observed latencies fell, + respectively. .. option:: significant_figures=int diff --git a/fio.1 b/fio.1 index a58632b4..0c1a5c76 100644 --- a/fio.1 +++ b/fio.1 @@ -3000,23 +3000,24 @@ Disable measurements of submission latency numbers. See Disable measurements of throughput/bandwidth numbers. See \fBdisable_lat\fR. .TP +.BI slat_percentiles \fR=\fPbool +Report submission latency percentiles. Submission latency is not recorded +for synchronous ioengines. +.TP .BI clat_percentiles \fR=\fPbool -Enable the reporting of percentiles of completion latencies. This option is -mutually exclusive with \fBlat_percentiles\fR. +Report completion latency percentiles. .TP .BI lat_percentiles \fR=\fPbool -Enable the reporting of percentiles of I/O latencies. This is similar to -\fBclat_percentiles\fR, except that this includes the submission latency. -This option is mutually exclusive with \fBclat_percentiles\fR. +Report total latency percentiles. Total latency is the sum of submission +latency and completion latency. .TP .BI percentile_list \fR=\fPfloat_list -Overwrite the default list of percentiles for completion latencies and the -block error histogram. Each number is a floating number in the range +Overwrite the default list of percentiles for latencies and the +block error histogram. Each number is a floating point number in the range (0,100], and the maximum length of the list is 20. Use ':' to separate the -numbers, and list the numbers in ascending order. For example, -`\-\-percentile_list=99.5:99.9' will cause fio to report the values of -completion latency below which 99.5% and 99.9% of the observed latencies -fell, respectively. +numbers. For example, `\-\-percentile_list=99.5:99.9' will cause fio to +report the latency durations below which 99.5% and 99.9% of the observed +latencies fell, respectively. .TP .BI significant_figures \fR=\fPint If using \fB\-\-output\-format\fR of `normal', set the significant figures