Add completion latency percentiles to terse output format

[fio.git] / HOWTO

diff --git a/HOWTO b/HOWTO
index 11ade8c1a500440f27d1774257ef0c9754020877..a0d244bc6daf3d92f8c4786f27a055761ae59906 100644 (file)
--- a/HOWTO
+++ b/HOWTO
@@ -1365,12 +1365,14 @@ Split up, the format is as follows:
                Total IO (KB), bandwidth (KB/sec), IOPS, runtime (msec)
                Submission latency: min, max, mean, deviation
                Completion latency: min, max, mean, deviation
+               Completion latency percentiles: 20 fields (see below)
                Total latency: min, max, mean, deviation
                Bw: min, max, aggregate percentage of total, mean, deviation
        WRITE status:
                Total IO (KB), bandwidth (KB/sec), IOPS, runtime (msec)
                Submission latency: min, max, mean, deviation
                Completion latency: min, max, mean, deviation
+               Completion latency percentiles: 20 fields (see below)
                Total latency: min, max, mean, deviation
                Bw: min, max, aggregate percentage of total, mean, deviation
        CPU usage: user, system, context switches, major faults, minor faults
@@ -1381,6 +1383,13 @@ Split up, the format is as follows:
        
        Additional Info (dependant on description being set): Text description
 
+Completion latency percentiles can be a grouping of up to 20 sets, so
+for the terse output fio writes all of them. Each field will look like this:
+
+       1.00%=6112
+
+which is the Xth percentile, and the usec latency associated with it.
+
 
 8.0 Trace file format
 ---------------------