Document compress_buffer_percentage, compress_buffer_chunk
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/HOWTO b/HOWTO
index 30e4059..e4614ea 100644
--- a/HOWTO
+++ b/HOWTO
@@ -488,6 +488,22 @@
block compression attempts, but it will stop naive dedupe of
blocks. Default: true.
+buffer_compress_percentage=int If this is set, then fio will attempt to
+ provide IO buffer content (on WRITEs) that compress to
+ the specified level. Fio does this by providing a mix of
+ random data and zeroes. Note that this is per block size
+ unit, for file/disk wide compression level that matches
+ this setting, you'll also want to set refill_buffers.
+
+buffer_compress_chunk=int See buffer_compress_percentage. This
+ setting allows fio to manage how big the ranges of random
+ data and zeroed data is. Without this set, fio will
+ provide buffer_compress_percentage of blocksize random
+ data, followed by the remaining zeroed. With this set
+ to some chunk size smaller than the block size, fio can
+ alternate random and zeroed data throughout the IO
+ buffer.
+
nrfiles=int Number of files to use for this job. Defaults to 1.
openfiles=int Number of files to keep open at the same time. Defaults to
diff --git a/fio.1 b/fio.1
index f7abff8..c4c90b4 100644
--- a/fio.1
+++ b/fio.1
@@ -359,6 +359,20 @@
more clever block compression attempts, but it will stop naive dedupe
of blocks. Default: true.
.TP
+.BI buffer_compress_percentage \fR=\fPint
+If this is set, then fio will attempt to provide IO buffer content (on WRITEs)
+that compress to the specified level. Fio does this by providing a mix of
+random data and zeroes. Note that this is per block size unit, for file/disk
+wide compression level that matches this setting, you'll also want to set
+\fBrefill_buffers\fR.
+.TP
+.BI buffer_compress_chunk \fR=\fPint
+See \fBbuffer_compress_percentage\fR. This setting allows fio to manage how
+big the ranges of random data and zeroed data is. Without this set, fio will
+provide \fBbuffer_compress_percentage\fR of blocksize random data, followed by
+the remaining zeroed. With this set to some chunk size smaller than the block
+size, fio can alternate random and zeroed data throughout the IO buffer.
+.TP
.BI nrfiles \fR=\fPint
Number of files to use for this job. Default: 1.
.TP