From: Jens Axboe <jens.axboe@oracle.com>
Date: Tue, 27 Mar 2007 08:59:49 +0000 (+0200)
Subject: Improve random verify block sorting
X-Git-Tag: fio-1.15~26
X-Git-Url: https://git.kernel.dk/?p=fio.git;a=commitdiff_plain;h=160b966d83adace2629de10f85ed269ab2e587f5

Improve random verify block sorting

Add an option to control it and also check the nosort flag in file
layout to further catch a case where sorting isn't needed.

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

diff --git a/HOWTO b/HOWTO
index a5be9dbd..7cab0537 100644
--- a/HOWTO
+++ b/HOWTO
@@ -563,6 +563,14 @@ verify=str	If writing to a file, fio can verify the file contents
 		system to make sure that the written data is also
 		correctly read back.
 
+verifysort=bool	If set, fio will sort written verify blocks when it deems
+		it faster to read them back in a sorted manner. This is
+		often the case when overwriting an existing file, since
+		the blocks are already laid out in the file system. You
+		can ignore this option unless doing huge amounts of really
+		fast IO where the red-black tree sorting CPU time becomes
+		significant.
+		
 stonewall	Wait for preceeding jobs in the job file to exit, before
 		starting this one. Can be used to insert serialization
 		points in the job file. A stone wall also implies starting
diff --git a/filesetup.c b/filesetup.c
index d8b7401b..a059df66 100644
--- a/filesetup.c
+++ b/filesetup.c
@@ -249,6 +249,7 @@ static int create_files(struct thread_data *td)
 			if (td->o.unlink)
 				f->flags |= FIO_FILE_UNLINK;
 
+			f->flags |= FIO_FILE_NOSORT;
 			err = create_file(td, f);
 			if (err)
 				break;
diff --git a/fio.h b/fio.h
index ec08e423..ddc7e239 100644
--- a/fio.h
+++ b/fio.h
@@ -238,6 +238,7 @@ enum fio_file_flags {
 	FIO_FILE_UNLINK		= 1 << 1,	/* unlink on close */
 	FIO_FILE_CLOSING	= 1 << 2,	/* file being closed */
 	FIO_FILE_EXISTS		= 1 << 3,	/* no need to create */
+	FIO_FILE_NOSORT		= 1 << 4,	/* don't sort verify blocks */
 };
 
 /*
@@ -356,6 +357,7 @@ struct thread_options {
 	unsigned int end_fsync;
 	unsigned int sync_io;
 	unsigned int verify;
+	unsigned int verifysort;
 	unsigned int use_thread;
 	unsigned int unlink;
 	unsigned int do_disk_util;
diff --git a/log.c b/log.c
index 6c7c4d6b..45be5fb6 100644
--- a/log.c
+++ b/log.c
@@ -60,7 +60,8 @@ void log_io_piece(struct thread_data *td, struct io_u *io_u)
 	 * For both these cases, just reading back data in the order we
 	 * wrote it out is the fastest.
 	 */
-	if (!td_random(td) || !td->o.overwrite) {
+	if (!td_random(td) || !td->o.overwrite ||
+	     (io_u->file->flags & FIO_FILE_NOSORT)) {
 		INIT_LIST_HEAD(&ipo->list);
 		list_add_tail(&ipo->list, &td->io_hist_list);
 		return;
diff --git a/options.c b/options.c
index 5401f903..aeba5201 100644
--- a/options.c
+++ b/options.c
@@ -538,6 +538,13 @@ static struct fio_option options[] = {
 			  },
 		},
 	},
+	{
+		.name	= "verifysort",
+		.type	= FIO_OPT_BOOL,
+		.off1	= td_var_offset(verifysort),
+		.help	= "Sort written verify blocks for read back",
+		.def	= "1",
+	},
 	{
 		.name	= "write_iolog",
 		.type	= FIO_OPT_STR_STORE,