blktrace support: fixups/cleanups/improvements
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/blktrace.c b/blktrace.c
index 698d16f..8ba538a 100644
--- a/blktrace.c
+++ b/blktrace.c
@@ -8,7 +8,7 @@
#include "fio.h"
#include "blktrace_api.h"
-#define TRACE_FIFO_SIZE (sizeof(struct blk_io_trace) * 1000)
+#define TRACE_FIFO_SIZE 65536
/*
* fifo refill frontend, to avoid reading data in trace sized bites
@@ -16,28 +16,23 @@
static int refill_fifo(struct thread_data *td, struct fifo *fifo, int fd)
{
char buf[TRACE_FIFO_SIZE];
- unsigned int total, left;
- void *ptr;
+ unsigned int total;
int ret;
- total = 0;
- ptr = buf;
- while (total < TRACE_FIFO_SIZE) {
- left = TRACE_FIFO_SIZE - total;
+ total = sizeof(buf);
+ if (total > fifo_room(fifo))
+ total = fifo_room(fifo);
- ret = read(fd, ptr, left);
- if (ret < 0) {
- td_verror(td, errno, "read blktrace file");
- return -1;
- } else if (!ret)
- break;
-
- fifo_put(fifo, ptr, ret);
- ptr += ret;
- total += ret;
+ ret = read(fd, buf, total);
+ if (ret < 0) {
+ td_verror(td, errno, "read blktrace file");
+ return -1;
}
- return 0;
+ if (ret > 0)
+ ret = fifo_put(fifo, buf, ret);
+
+ return ret;
}
/*
@@ -46,17 +41,12 @@
static int trace_fifo_get(struct thread_data *td, struct fifo *fifo, int fd,
void *buf, unsigned int len)
{
- int ret;
+ if (fifo_len(fifo) < len) {
+ int ret = refill_fifo(td, fifo, fd);
- if (fifo_len(fifo) >= len)
- return fifo_get(fifo, buf, len);
-
- ret = refill_fifo(td, fifo, fd);
- if (ret < 0)
- return ret;
-
- if (fifo_len(fifo) < len)
- return 0;
+ if (ret < 0)
+ return ret;
+ }
return fifo_get(fifo, buf, len);
}
@@ -64,15 +54,13 @@
/*
* Just discard the pdu by seeking past it.
*/
-static int discard_pdu(int fd, struct blk_io_trace *t)
+static int discard_pdu(struct thread_data *td, struct fifo *fifo, int fd,
+ struct blk_io_trace *t)
{
if (t->pdu_len == 0)
return 0;
- if (lseek(fd, t->pdu_len, SEEK_CUR) < 0)
- return errno;
-
- return 0;
+ return trace_fifo_get(td, fifo, fd, NULL, t->pdu_len);
}
/*
@@ -203,17 +191,20 @@
}
if ((t.magic & 0xffffff00) != BLK_IO_TRACE_MAGIC) {
- log_err("fio: bad magic in blktrace data\n");
+ log_err("fio: bad magic in blktrace data: %x\n", t.magic);
goto err;
}
if ((t.magic & 0xff) != BLK_IO_TRACE_VERSION) {
log_err("fio: bad blktrace version %d\n", t.magic & 0xff);
goto err;
}
- ret = discard_pdu(fd, &t);
- if (ret) {
+ ret = discard_pdu(td, fifo, fd, &t);
+ if (ret < 0) {
td_verror(td, ret, "blktrace lseek");
goto err;
+ } else if (t.pdu_len != ret) {
+ log_err("fio: discarded %d of %d\n", ret, t.pdu_len);
+ goto err;
}
if (!ttime) {
ttime = t.time;
diff --git a/fifo.c b/fifo.c
index 5406aa5..df165f7 100644
--- a/fifo.c
+++ b/fifo.c
@@ -35,7 +35,7 @@
fifo->buffer = malloc(size);
fifo->size = size;
- fifo->in = fifo->out = 0xffff0000;
+ fifo->in = fifo->out = 0;
return fifo;
}