X-Git-Url: https://git.kernel.dk/?a=blobdiff_plain;f=HOWTO;h=dce96bcd8103f075d56b21173659f3061f6600b1;hb=c492cb1a9b1c327e985c89eb517d58bd5323880c;hp=f151350ce39b221246316848c4648b80b7a9b1c0;hpb=e2b7f9fb0d105de217fe97817b47c594232ac14f;p=fio.git

diff --git a/HOWTO b/HOWTO
index f151350c..dce96bcd 100644
--- a/HOWTO
+++ b/HOWTO
@@ -1453,8 +1453,8 @@ Buffers and memory
 	mix of random data and a fixed pattern. The fixed pattern is either zeros,
 	or the pattern specified by :option:`buffer_pattern`. If the pattern option
 	is used, it might skew the compression ratio slightly. Note that this is per
-	block size unit, for file/disk wide compression level that matches this
-	setting, you'll also want to set :option:`refill_buffers`.
+	block size unit, see :option:`buffer_compress_chunk` for setting a finer
+	granularity of compression regions.
 
 .. option:: buffer_compress_chunk=int
 
@@ -1463,7 +1463,8 @@ Buffers and memory
 	will provide :option:`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
-	I/O buffer.
+	I/O buffer. This is particularly useful when bigger block sizes are used
+	for a job. Defaults to 512.
 
 .. option:: buffer_pattern=str
 
@@ -1819,6 +1820,11 @@ I/O engine
 			set  `filesize` so that all the accounting still occurs, but no
 			actual I/O will be done other than creating the file.
 
+		**libpmem**
+			Read and write using mmap I/O to a file on a filesystem
+			mounted with DAX on a persistent memory device through the NVML
+			libpmem library.
+
 I/O engine specific parameters
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~