t/io_uring: fixes

[fio.git] / HOWTO

diff --git a/HOWTO b/HOWTO
index 45cf0bdf4b7367a870f472d23aac8e45de60e43c..468772d7227a3a2c9a9cca50436e7c4bc4ebbf0b 100644 (file)
--- a/HOWTO
+++ b/HOWTO
@@ -2339,8 +2339,13 @@ I/O depth
        ``serialize_overlap`` tells fio to avoid provoking this behavior by explicitly
        serializing in-flight I/Os that have a non-zero overlap. Note that setting
        this option can reduce both performance and the :option:`iodepth` achieved.
-       Additionally this option does not work when :option:`io_submit_mode` is set to
-       offload. Default: false.
+
+       This option only applies to I/Os issued for a single job except when it is
+       enabled along with :option:`io_submit_mode`=offload. In offload mode, fio
+       will check for overlap among all I/Os submitted by offload jobs with :option:`serialize_overlap`
+       enabled.
+
+       Default: false.
 
 .. option:: io_submit_mode=str
 
@@ -2559,12 +2564,13 @@ I/O replay
 
 .. option:: replay_align=int
 
-       Force alignment of I/O offsets and lengths in a trace to this power of 2
-       value.
+       Force alignment of the byte offsets in a trace to this value. The value
+       must be a power of 2.
 
 .. option:: replay_scale=int
 
-       Scale sector offsets down by this factor when replaying traces.
+       Scale byte offsets down by this factor when replaying traces. Should most
+       likely use :option:`replay_align` as well.
 
 .. option:: replay_skip=str
 
@@ -3000,6 +3006,10 @@ Steady state
        data from the rolling collection window. Threshold limits can be expressed
        as a fixed value or as a percentage of the mean in the collection window.
 
+       When using this feature, most jobs should include the :option:`time_based`
+       and :option:`runtime` options or the :option:`loops` option so that fio does not
+       stop running after it has covered the full size of the specified file(s) or device(s).
+
                **iops**
                        Collect IOPS data. Stop the job if all individual IOPS measurements
                        are within the specified limit of the mean IOPS (e.g., ``iops:2``