X-Git-Url: https://git.kernel.dk/?p=fio.git;a=blobdiff_plain;f=blktrace.c;h=1669fe556bc3324d2b40567e0afdab0f0e359667;hp=988ce5917cd564f13aadd00402501e7f6713385a;hb=6df8adaaadb71340b47f2c3e971297b656082ca5;hpb=fdefd987d7ba284c7a9e101911c4b8e72fe326ad

diff --git a/blktrace.c b/blktrace.c
index 988ce591..1669fe55 100644
--- a/blktrace.c
+++ b/blktrace.c
@@ -3,10 +3,14 @@
  */
 #include <stdio.h>
 #include <stdlib.h>
+
 #include "list.h"
 #include "fio.h"
 #include "blktrace_api.h"
 
+/*
+ * Just discard the pdu by seeking past it.
+ */
 static int discard_pdu(int fd, struct blk_io_trace *t)
 {
 	if (t->pdu_len == 0)
@@ -18,6 +22,10 @@ static int discard_pdu(int fd, struct blk_io_trace *t)
 	return 0;
 }
 
+/*
+ * Check if this is a blktrace binary data file. We read a single trace
+ * into memory and check for the magic signature.
+ */
 int is_blktrace(const char *filename)
 {
 	struct blk_io_trace t;
@@ -46,15 +54,22 @@ int is_blktrace(const char *filename)
 	return 0;
 }
 
+/*
+ * Store blk_io_trace data in an ipo for later retrieval.
+ */
 static void store_ipo(struct thread_data *td, unsigned long long offset,
-		      unsigned int bytes, int rw)
+		      unsigned int bytes, int rw, unsigned long long ttime)
 {
 	struct io_piece *ipo = malloc(sizeof(*ipo));
 
 	memset(ipo, 0, sizeof(*ipo));
 	INIT_LIST_HEAD(&ipo->list);
-	ipo->offset = offset;
+	/*
+	 * the 512 is wrong here, it should be the hardware sector size...
+	 */
+	ipo->offset = offset * 512;
 	ipo->len = bytes;
+	ipo->delay = ttime / 1000;
 	if (rw)
 		ipo->ddir = DDIR_WRITE;
 	else
@@ -63,20 +78,41 @@ static void store_ipo(struct thread_data *td, unsigned long long offset,
 	list_add_tail(&ipo->list, &td->io_log_list);
 }
 
-static void handle_trace(struct thread_data *td, struct blk_io_trace *t)
+/*
+ * We only care for queue traces, most of the others are side effects
+ * due to internal workings of the block layer.
+ */
+static void handle_trace(struct thread_data *td, struct blk_io_trace *t,
+			 unsigned long long ttime, unsigned long *ios)
 {
 	int rw;
 
 	if ((t->action & 0xffff) != __BLK_TA_QUEUE)
 		return;
+	if (t->action & BLK_TC_ACT(BLK_TC_PC))
+		return;
 
-	w = (t->action & BLK_TC_ACT(BLK_TC_WRITE)) != 0;
-	store_ipo(td, t->sector, t->bytes, rw);
+	/*
+	 * should not happen, need to look into that...
+	 */
+	if (!t->bytes)
+		return;
+
+	rw = (t->action & BLK_TC_ACT(BLK_TC_WRITE)) != 0;
+	ios[rw]++;
+	td->o.size += t->bytes;
+	store_ipo(td, t->sector, t->bytes, rw, ttime);
 }
 
+/*
+ * Load a blktrace file by reading all the blk_io_trace entries, and storing
+ * them as io_pieces like the fio text version would do.
+ */
 int load_blktrace(struct thread_data *td, const char *filename)
 {
+	unsigned long long ttime;
 	struct blk_io_trace t;
+	unsigned long ios[2];
 	int fd;
 
 	fd = open(filename, O_RDONLY);
@@ -85,35 +121,68 @@ int load_blktrace(struct thread_data *td, const char *filename)
 		return 1;
 	}
 
+	td->o.size = 0;
+
+	ios[0] = ios[1] = 0;
+	ttime = 0;
 	do {
+		/*
+		 * Once this is working fully, I'll add a layer between
+		 * here and read to cache trace data. Then we can avoid
+		 * doing itsy bitsy reads, but instead pull in a larger
+		 * chunk of data at the time.
+		 */
 		int ret = read(fd, &t, sizeof(t));
 
 		if (ret < 0) {
 			td_verror(td, errno, "read blktrace file");
-			return 1;
+			goto err;
 		} else if (!ret) {
 			break;
 		} else if (ret != sizeof(t)) {
 			log_err("fio: short read on blktrace file\n");
-			return 1;
+			goto err;
 		}
 
 		if ((t.magic & 0xffffff00) != BLK_IO_TRACE_MAGIC) {
 			log_err("fio: bad magic in blktrace data\n");
-			return 1;
+			goto err;
 		}
 		if ((t.magic & 0xff) != BLK_IO_TRACE_VERSION) {
 			log_err("fio: bad blktrace version %d\n", t.magic & 0xff);
-			return 1;
+			goto err;
 		}
 		ret = discard_pdu(fd, &t);
 		if (ret) {
 			td_verror(td, ret, "blktrace lseek");
-			return 1;
+			goto err;
 		}
-		handle_trace(td, &t);
+		if (!ttime)
+			ttime = t.time;
+		handle_trace(td, &t, t.time - ttime, ios);
+		ttime = t.time;
 	} while (1);
 
 	close(fd);
+
+	if (!ios[DDIR_READ] && !ios[DDIR_WRITE]) {
+		log_err("fio: found no ios in blktrace data\n");
+		return 1;
+	} else if (ios[DDIR_READ] && !ios[DDIR_READ])
+		td->o.td_ddir = TD_DDIR_READ;
+	else if (!ios[DDIR_READ] && ios[DDIR_WRITE])
+		td->o.td_ddir = TD_DDIR_WRITE;
+	else
+		td->o.td_ddir = TD_DDIR_RW;
+
+	/*
+	 * We need to do direct/raw ios to the device, to avoid getting
+	 * read-ahead in our way.
+	 */
+	td->o.odirect = 1;
+
 	return 0;
+err:
+	close(fd);
+	return 1;
 }