From: Jens Axboe <jens.axboe@oracle.com>
Date: Wed, 14 Mar 2007 09:59:33 +0000 (+0100)
Subject: Update io engine comments
X-Git-Tag: fio-1.14~2
X-Git-Url: https://git.kernel.dk/?p=fio.git;a=commitdiff_plain;h=da751ca9665bcdeca56d2eec5b629a0953c07662;hp=cfc99db7b9e806e7739b360dfa005360d0fe8837

Update io engine comments

Some were plain wrong, mainly because they were born through
copying an existing engine.

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

diff --git a/engines/cpu.c b/engines/cpu.c
index b6f9075d..d10669df 100644
--- a/engines/cpu.c
+++ b/engines/cpu.c
@@ -1,3 +1,10 @@
+/*
+ * CPU engine
+ *
+ * Doesn't transfer any data, merely burns CPU cycles according to
+ * the settings.
+ *
+ */
 #include "../fio.h"
 #include "../os.h"
 
diff --git a/engines/libaio.c b/engines/libaio.c
index 5295eadf..78f43ef1 100644
--- a/engines/libaio.c
+++ b/engines/libaio.c
@@ -1,5 +1,7 @@
 /*
- * native linux aio io engine
+ * libaio engine
+ *
+ * IO engine using the Linux native aio interface.
  *
  */
 #include <stdio.h>
diff --git a/engines/mmap.c b/engines/mmap.c
index 0922e97e..17cf5fcf 100644
--- a/engines/mmap.c
+++ b/engines/mmap.c
@@ -1,5 +1,8 @@
 /*
- * regular read/write sync io engine
+ * mmap engine
+ *
+ * IO engine that reads/writes from files by doing memcpy to/from
+ * a memory mapped region of the file.
  *
  */
 #include <stdio.h>
diff --git a/engines/net.c b/engines/net.c
index cd1fda9f..51bc671f 100644
--- a/engines/net.c
+++ b/engines/net.c
@@ -1,5 +1,8 @@
 /*
- * Transfer data over the net.
+ * net engine
+ *
+ * IO engine that reads/writes to/from sockets.
+ *
  */
 #include <stdio.h>
 #include <stdlib.h>
diff --git a/engines/null.c b/engines/null.c
index 42a780aa..6397ec07 100644
--- a/engines/null.c
+++ b/engines/null.c
@@ -1,5 +1,8 @@
 /*
- * null engine - doesn't do any transfers. Used to test fio.
+ * null engine
+ *
+ * IO engine that doesn't do any real IO transfers, it just pretends to.
+ * The main purpose is to test fio itself.
  *
  */
 #include <stdio.h>
diff --git a/engines/posixaio.c b/engines/posixaio.c
index 9ee3ca6b..7d9aaaf1 100644
--- a/engines/posixaio.c
+++ b/engines/posixaio.c
@@ -1,5 +1,7 @@
 /*
- * posix aio io engine
+ * posixaio engine
+ *
+ * IO engine that uses the posix defined aio interface.
  *
  */
 #include <stdio.h>
diff --git a/engines/sg.c b/engines/sg.c
index 98ecbd1c..84c2afe6 100644
--- a/engines/sg.c
+++ b/engines/sg.c
@@ -1,5 +1,7 @@
 /*
- * scsi generic sg v3 io engine
+ * sg engine
+ *
+ * IO engine that uses the Linux SG v3 interface to talk to SCSI devices
  *
  */
 #include <stdio.h>
diff --git a/engines/splice.c b/engines/splice.c
index c366a2eb..59bf7e4f 100644
--- a/engines/splice.c
+++ b/engines/splice.c
@@ -1,5 +1,8 @@
 /*
- * splice io engine
+ * splice engine
+ *
+ * IO engine that transfers data by doing splices to/from pipes and
+ * the files.
  *
  */
 #include <stdio.h>
diff --git a/engines/sync.c b/engines/sync.c
index b1776d21..a1372827 100644
--- a/engines/sync.c
+++ b/engines/sync.c
@@ -1,5 +1,8 @@
 /*
- * regular read/write sync io engine
+ * sync engine
+ *
+ * IO engine that does regular read(2)/write(2) with lseek(2) to transfer
+ * data.
  *
  */
 #include <stdio.h>
diff --git a/engines/syslet-rw.c b/engines/syslet-rw.c
index fe400daa..279884a5 100644
--- a/engines/syslet-rw.c
+++ b/engines/syslet-rw.c
@@ -1,5 +1,8 @@
 /*
- * read/write() engine that uses syslet to be async
+ * syslet engine
+ *
+ * IO engine that does regular pread(2)/pwrite(2) to transfer data, but
+ * with syslets to make the execution async.
  *
  */
 #include <stdio.h>