From: Jens Axboe <jens.axboe@oracle.com>
Date: Tue, 15 May 2007 12:29:58 +0000 (+0200)
Subject: blktrace replay: delay support
X-Git-Tag: fio-1.16.2~21
X-Git-Url: https://git.kernel.dk/?p=fio.git;a=commitdiff_plain;h=a61eddecca21d19f3f4c297400d6c5d93dc29259;hp=6df8adaaadb71340b47f2c3e971297b656082ca5

blktrace replay: delay support

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

diff --git a/blktrace.c b/blktrace.c
index 1669fe55..5793773a 100644
--- a/blktrace.c
+++ b/blktrace.c
@@ -110,9 +110,10 @@ static void handle_trace(struct thread_data *td, struct blk_io_trace *t,
  */
 int load_blktrace(struct thread_data *td, const char *filename)
 {
-	unsigned long long ttime;
+	unsigned long long ttime, delay;
 	struct blk_io_trace t;
 	unsigned long ios[2];
+	unsigned int cpu;
 	int fd;
 
 	fd = open(filename, O_RDONLY);
@@ -125,6 +126,7 @@ int load_blktrace(struct thread_data *td, const char *filename)
 
 	ios[0] = ios[1] = 0;
 	ttime = 0;
+	cpu = 0;
 	do {
 		/*
 		 * Once this is working fully, I'll add a layer between
@@ -157,10 +159,16 @@ int load_blktrace(struct thread_data *td, const char *filename)
 			td_verror(td, ret, "blktrace lseek");
 			goto err;
 		}
-		if (!ttime)
+		if (!ttime) {
 			ttime = t.time;
-		handle_trace(td, &t, t.time - ttime, ios);
+			cpu = t.cpu;
+		}
+		delay = 0;
+		if (cpu == t.cpu)
+			delay = t.time - ttime;
+		handle_trace(td, &t, delay, ios);
 		ttime = t.time;
+		cpu = t.cpu;
 	} while (1);
 
 	close(fd);
diff --git a/fio.h b/fio.h
index 870b6704..fa0edb1e 100644
--- a/fio.h
+++ b/fio.h
@@ -522,6 +522,7 @@ struct thread_data {
 	struct timeval start;	/* start of this loop */
 	struct timeval epoch;	/* time job was started */
 	struct timeval rw_end[2];
+	struct timeval last_issue;
 	unsigned int rw_end_set[2];
 
 	/*
diff --git a/ioengines.c b/ioengines.c
index 28cdfd49..feb986a8 100644
--- a/ioengines.c
+++ b/ioengines.c
@@ -192,6 +192,7 @@ int td_io_queue(struct thread_data *td, struct io_u *io_u)
 
 	if (td->io_ops->flags & FIO_SYNCIO) {
 		fio_gettime(&io_u->issue_time, NULL);
+		memcpy(&td->last_issue, &io_u->issue_time, sizeof(struct timeval));
 
 		/*
 		 * for a sync engine, set the timeout upfront
@@ -220,6 +221,7 @@ int td_io_queue(struct thread_data *td, struct io_u *io_u)
 
 	if ((td->io_ops->flags & FIO_SYNCIO) == 0) {
 		fio_gettime(&io_u->issue_time, NULL);
+		memcpy(&td->last_issue, &io_u->issue_time, sizeof(struct timeval));
 
 		/*
 		 * async engine, set the timeout here
diff --git a/log.c b/log.c
index c0e9d4ae..5ed30eb6 100644
--- a/log.c
+++ b/log.c
@@ -8,6 +8,24 @@ void write_iolog_put(struct thread_data *td, struct io_u *io_u)
 	fprintf(td->iolog_f, "%u,%llu,%lu\n", io_u->ddir, io_u->offset, io_u->buflen);
 }
 
+static void iolog_delay(struct thread_data *td, unsigned long delay)
+{
+	unsigned long usec = utime_since_now(&td->last_issue);
+
+	if (delay < usec)
+		return;
+
+	delay -= usec;
+
+	/*
+	 * less than 100 usec delay, just regard it as noise
+	 */
+	if (delay < 100)
+		return;
+
+	usec_sleep(td, delay);
+}
+
 int read_iolog_get(struct thread_data *td, struct io_u *io_u)
 {
 	struct io_piece *ipo;
@@ -19,6 +37,10 @@ int read_iolog_get(struct thread_data *td, struct io_u *io_u)
 		io_u->buflen = ipo->len;
 		io_u->ddir = ipo->ddir;
 		io_u->file = ipo->file;
+
+		if (ipo->delay)
+			iolog_delay(td, ipo->delay);
+
 		/*
 		 * work around, this needs a format change to work for > 1 file
 		 */