In fio.1 and HOWTO, add link to Poisson process in wikipedia

Signed-off-by: Jens Axboe <axboe@fb.com>

diff --git a/HOWTO b/HOWTO
index 03a0060c4ede820428d491f7d10b4a8143c07ed6..f8b488faac91285682cb9a9027b9ddaa7ecc804a 100644 (file)
--- a/HOWTO
+++ b/HOWTO
@@ -1064,8 +1064,11 @@ rate_iops_min=int If fio doesn't meet this rate of IO, it will cause
                the job to exit. The same format as rate is used for read vs
                write separation.
 
-rate_poisson=bool      When rate limited, try to simulate request flow under
-               Poisson process (instead of even distribution). Default: false.
+rate_poisson=bool      Real world random request flow follows Poisson process
+               (https://en.wikipedia.org/wiki/Poisson_process). With
+               rate_poisson=1, fio tries to simulate request flow under Poisson
+               process (instead of even distribution, which is the default).
+               Default: false.
 
 latency_target=int     If set, fio will attempt to find the max performance
                point that the given workload will run at while maintaining a

diff --git a/fio.1 b/fio.1
index 99d9f9e07e63a7ccb2c6462bef9e70843ebc82a0..b8e31db691842695567d7e058733d6051c91384f 100644 (file)
--- a/fio.1
+++ b/fio.1
@@ -964,8 +964,10 @@ If this rate of I/O is not met, the job will exit. The same format as \fBrate\fR
 is used for read vs write separation.
 .TP
 .BI rate_poisson \fR=\fPbool
-When rate limited, try to simulate request flow under Poisson process (instead
-of even distribution). Default: false.
+Real world random request flow follows Poisson process
+(https://en.wikipedia.org/wiki/Poisson_process). With \fBrate_poisson\fR=1, fio
+tries to simulate request flow under Poisson process (instead of even
+distribution, which is the default). Default: false.
 .TP
 .BI ratecycle \fR=\fPint
 Average bandwidth for \fBrate\fR and \fBratemin\fR over this number of