blktrace support: fixups/cleanups/improvements

[fio.git] / blktrace.c

diff --git a/blktrace.c b/blktrace.c
index 698d16ff11949482d1099283db5a06b7cc2bde67..8ba538ae8abc57dc1093df9273b2a894aae81cd8 100644 (file)
--- 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 refill_fifo(struct thread_data *td, struct fifo *fifo, int fd)
 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)
-               return fifo_get(fifo, buf, len);
+       if (fifo_len(fifo) < len) {
+               int ret = refill_fifo(td, fifo, fd);
 
-       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 @@ static int trace_fifo_get(struct thread_data *td, struct fifo *fifo, int fd,
 /*
  * 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 @@ int load_blktrace(struct thread_data *td, const char *filename)
                }
 
                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;