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.
 
                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
 
 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
 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
 .TP
 .BI ratecycle \fR=\fPint
 Average bandwidth for \fBrate\fR and \fBratemin\fR over this number of