Add gtod_reduce option
[fio.git] / HOWTO
diff --git a/HOWTO b/HOWTO
index 1d1aa61..f4efd28 100644 (file)
--- a/HOWTO
+++ b/HOWTO
@@ -848,6 +848,13 @@ disable_slat=bool Disable measurements of submission latency numbers. See
 disable_bw=bool        Disable measurements of throughput/bandwidth numbers. See
                disable_clat.
 
+gtod_reduce=bool Enable all of the gettimeofday() reducing options
+               (disable_clat, disable_slat, disable_bw) plus reduce
+               precision of the timeout somewhat to really shrink
+               the gettimeofday() call count. With this option enabled,
+               we only do about 0.4% of the gtod() calls we would have
+               done if all time keeping was enabled.
+
 
 6.0 Interpreting the output
 ---------------------------