*/
#include <stdio.h>
#include <stdlib.h>
+#include <unistd.h>
-#include "list.h"
+#include "flist.h"
#include "fio.h"
+#include "blktrace.h"
#include "blktrace_api.h"
+#include "oslib/linux-dev-lookup.h"
+
+#define TRACE_FIFO_SIZE 8192
+
+/*
+ * fifo refill frontend, to avoid reading data in trace sized bites
+ */
+static int refill_fifo(struct thread_data *td, struct fifo *fifo, int fd)
+{
+ char buf[TRACE_FIFO_SIZE];
+ unsigned int total;
+ int ret;
+
+ total = sizeof(buf);
+ if (total > fifo_room(fifo))
+ total = fifo_room(fifo);
+
+ ret = read(fd, buf, total);
+ if (ret < 0) {
+ int read_err = errno;
+
+ assert(read_err > 0);
+ td_verror(td, read_err, "read blktrace file");
+ return -read_err;
+ }
+
+ if (ret > 0)
+ ret = fifo_put(fifo, buf, ret);
+
+ dprint(FD_BLKTRACE, "refill: filled %d bytes\n", ret);
+ return ret;
+}
+
+/*
+ * Retrieve 'len' bytes from the fifo, refilling if necessary.
+ */
+static int trace_fifo_get(struct thread_data *td, struct fifo *fifo, int fd,
+ void *buf, unsigned int len)
+{
+ if (fifo_len(fifo) < len) {
+ int ret = refill_fifo(td, fifo, fd);
+
+ if (ret < 0)
+ return ret;
+ }
+
+ return fifo_get(fifo, buf, len);
+}
/*
* 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;
+ dprint(FD_BLKTRACE, "discard pdu len %u\n", t->pdu_len);
+ return trace_fifo_get(td, fifo, fd, NULL, t->pdu_len);
}
/*
* 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)
+bool is_blktrace(const char *filename, int *need_swap)
{
struct blk_io_trace t;
int fd, ret;
fd = open(filename, O_RDONLY);
- if (fd < 0) {
- perror("open blktrace");
- return 0;
- }
+ if (fd < 0)
+ return false;
ret = read(fd, &t, sizeof(t));
close(fd);
if (ret < 0) {
perror("read blktrace");
- return 0;
+ return false;
} else if (ret != sizeof(t)) {
log_err("fio: short read on blktrace file\n");
- return 0;
+ return false;
}
- if ((t.magic & 0xffffff00) == BLK_IO_TRACE_MAGIC)
- return 1;
+ if ((t.magic & 0xffffff00) == BLK_IO_TRACE_MAGIC) {
+ *need_swap = 0;
+ return true;
+ }
- return 0;
+ /*
+ * Maybe it needs to be endian swapped...
+ */
+ t.magic = fio_swap32(t.magic);
+ if ((t.magic & 0xffffff00) == BLK_IO_TRACE_MAGIC) {
+ *need_swap = 1;
+ return true;
+ }
+
+ return false;
+}
+
+#define FMINORBITS 20
+#define FMINORMASK ((1U << FMINORBITS) - 1)
+#define FMAJOR(dev) ((unsigned int) ((dev) >> FMINORBITS))
+#define FMINOR(dev) ((unsigned int) ((dev) & FMINORMASK))
+
+static void trace_add_open_close_event(struct thread_data *td, int fileno, enum file_log_act action)
+{
+ struct io_piece *ipo;
+
+ ipo = calloc(1, sizeof(*ipo));
+ init_ipo(ipo);
+
+ ipo->ddir = DDIR_INVAL;
+ ipo->fileno = fileno;
+ ipo->file_action = action;
+ flist_add_tail(&ipo->list, &td->io_log_list);
+}
+
+static int trace_add_file(struct thread_data *td, __u32 device)
+{
+ static unsigned int last_maj, last_min, last_fileno;
+ unsigned int maj = FMAJOR(device);
+ unsigned int min = FMINOR(device);
+ struct fio_file *f;
+ char dev[256];
+ unsigned int i;
+
+ if (last_maj == maj && last_min == min)
+ return last_fileno;
+
+ last_maj = maj;
+ last_min = min;
+
+ /*
+ * check for this file in our list
+ */
+ for_each_file(td, f, i)
+ if (f->major == maj && f->minor == min) {
+ last_fileno = f->fileno;
+ return last_fileno;
+ }
+
+ strcpy(dev, "/dev");
+ if (blktrace_lookup_device(td->o.replay_redirect, dev, maj, min)) {
+ int fileno;
+
+ if (td->o.replay_redirect)
+ dprint(FD_BLKTRACE, "device lookup: %d/%d\n overridden"
+ " with: %s\n", maj, min,
+ td->o.replay_redirect);
+ else
+ dprint(FD_BLKTRACE, "device lookup: %d/%d\n", maj, min);
+
+ dprint(FD_BLKTRACE, "add devices %s\n", dev);
+ fileno = add_file_exclusive(td, dev);
+ td->o.open_files++;
+ td->files[fileno]->major = maj;
+ td->files[fileno]->minor = min;
+ trace_add_open_close_event(td, fileno, FIO_LOG_OPEN_FILE);
+ last_fileno = fileno;
+ }
+
+ return last_fileno;
+}
+
+static void t_bytes_align(struct thread_options *o, struct blk_io_trace *t)
+{
+ if (!o->replay_align)
+ return;
+
+ t->bytes = (t->bytes + o->replay_align - 1) & ~(o->replay_align - 1);
}
/*
* 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 long long ttime)
+ unsigned int bytes, int rw, unsigned long long ttime,
+ int fileno)
{
- struct io_piece *ipo = malloc(sizeof(*ipo));
+ struct io_piece *ipo;
+
+ ipo = calloc(1, sizeof(*ipo));
+ init_ipo(ipo);
- memset(ipo, 0, sizeof(*ipo));
- INIT_LIST_HEAD(&ipo->list);
- /*
- * the 512 is wrong here, it should be the hardware sector size...
- */
ipo->offset = offset * 512;
+ if (td->o.replay_scale)
+ ipo->offset = ipo->offset / td->o.replay_scale;
+ ipo_bytes_align(td->o.replay_align, ipo);
ipo->len = bytes;
ipo->delay = ttime / 1000;
if (rw)
ipo->ddir = DDIR_WRITE;
else
ipo->ddir = DDIR_READ;
+ ipo->fileno = fileno;
+
+ dprint(FD_BLKTRACE, "store ddir=%d, off=%llu, len=%lu, delay=%lu\n",
+ ipo->ddir, ipo->offset,
+ ipo->len, ipo->delay);
+ queue_io_piece(td, ipo);
+}
+
+static void handle_trace_notify(struct blk_io_trace *t)
+{
+ switch (t->action) {
+ case BLK_TN_PROCESS:
+ dprint(FD_BLKTRACE, "got process notify: %x, %d\n",
+ t->action, t->pid);
+ break;
+ case BLK_TN_TIMESTAMP:
+ dprint(FD_BLKTRACE, "got timestamp notify: %x, %d\n",
+ t->action, t->pid);
+ break;
+ case BLK_TN_MESSAGE:
+ break;
+ default:
+ dprint(FD_BLKTRACE, "unknown trace act %x\n", t->action);
+ break;
+ }
+}
+
+static void handle_trace_discard(struct thread_data *td,
+ struct blk_io_trace *t,
+ unsigned long long ttime,
+ unsigned long *ios, unsigned int *bs)
+{
+ struct io_piece *ipo;
+ int fileno;
+
+ if (td->o.replay_skip & (1u << DDIR_TRIM))
+ return;
+
+ ipo = calloc(1, sizeof(*ipo));
+ init_ipo(ipo);
+ fileno = trace_add_file(td, t->device);
+
+ ios[DDIR_TRIM]++;
+ if (t->bytes > bs[DDIR_TRIM])
+ bs[DDIR_TRIM] = t->bytes;
+
+ td->o.size += t->bytes;
+
+ INIT_FLIST_HEAD(&ipo->list);
- list_add_tail(&ipo->list, &td->io_log_list);
+ ipo->offset = t->sector * 512;
+ if (td->o.replay_scale)
+ ipo->offset = ipo->offset / td->o.replay_scale;
+ ipo_bytes_align(td->o.replay_align, ipo);
+ ipo->len = t->bytes;
+ ipo->delay = ttime / 1000;
+ ipo->ddir = DDIR_TRIM;
+ ipo->fileno = fileno;
+
+ dprint(FD_BLKTRACE, "store discard, off=%llu, len=%lu, delay=%lu\n",
+ ipo->offset, ipo->len,
+ ipo->delay);
+ queue_io_piece(td, ipo);
+}
+
+static void dump_trace(struct blk_io_trace *t)
+{
+ log_err("blktrace: ignoring zero byte trace: action=%x\n", t->action);
+}
+
+static void handle_trace_fs(struct thread_data *td, struct blk_io_trace *t,
+ unsigned long long ttime, unsigned long *ios,
+ unsigned int *bs)
+{
+ int rw;
+ int fileno;
+
+ fileno = trace_add_file(td, t->device);
+
+ rw = (t->action & BLK_TC_ACT(BLK_TC_WRITE)) != 0;
+
+ if (rw) {
+ if (td->o.replay_skip & (1u << DDIR_WRITE))
+ return;
+ } else {
+ if (td->o.replay_skip & (1u << DDIR_READ))
+ return;
+ }
+
+ if (!t->bytes) {
+ if (!fio_did_warn(FIO_WARN_BTRACE_ZERO))
+ dump_trace(t);
+ return;
+ }
+
+ if (t->bytes > bs[rw])
+ bs[rw] = t->bytes;
+
+ ios[rw]++;
+ td->o.size += t->bytes;
+ store_ipo(td, t->sector, t->bytes, rw, ttime, fileno);
+}
+
+static void handle_trace_flush(struct thread_data *td, struct blk_io_trace *t,
+ unsigned long long ttime, unsigned long *ios)
+{
+ struct io_piece *ipo;
+ int fileno;
+
+ if (td->o.replay_skip & (1u << DDIR_SYNC))
+ return;
+
+ ipo = calloc(1, sizeof(*ipo));
+ init_ipo(ipo);
+ fileno = trace_add_file(td, t->device);
+
+ ipo->delay = ttime / 1000;
+ ipo->ddir = DDIR_SYNC;
+ ipo->fileno = fileno;
+
+ ios[DDIR_SYNC]++;
+ dprint(FD_BLKTRACE, "store flush delay=%lu\n", ipo->delay);
+ queue_io_piece(td, ipo);
}
/*
* 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)
+ unsigned long *ios, unsigned int *bs)
{
- int rw;
+ static unsigned long long last_ttime;
+ unsigned long long delay = 0;
if ((t->action & 0xffff) != __BLK_TA_QUEUE)
return;
- if (t->action & BLK_TC_ACT(BLK_TC_PC))
- return;
- /*
- * should not happen, need to look into that...
- */
- if (!t->bytes)
- return;
+ if (!(t->action & BLK_TC_ACT(BLK_TC_NOTIFY))) {
+ if (!last_ttime || td->o.no_stall)
+ delay = 0;
+ else if (td->o.replay_time_scale == 100)
+ delay = t->time - last_ttime;
+ else {
+ double tmp = t->time - last_ttime;
+ double scale;
- rw = (t->action & BLK_TC_ACT(BLK_TC_WRITE)) != 0;
- ios[rw]++;
- store_ipo(td, t->sector, t->bytes, rw, ttime);
+ scale = (double) 100.0 / (double) td->o.replay_time_scale;
+ tmp *= scale;
+ delay = tmp;
+ }
+ last_ttime = t->time;
+ }
+
+ t_bytes_align(&td->o, t);
+
+ if (t->action & BLK_TC_ACT(BLK_TC_NOTIFY))
+ handle_trace_notify(t);
+ else if (t->action & BLK_TC_ACT(BLK_TC_DISCARD))
+ handle_trace_discard(td, t, delay, ios, bs);
+ else if (t->action & BLK_TC_ACT(BLK_TC_FLUSH))
+ handle_trace_flush(td, t, delay, ios);
+ else
+ handle_trace_fs(td, t, delay, ios, bs);
+}
+
+static void byteswap_trace(struct blk_io_trace *t)
+{
+ t->magic = fio_swap32(t->magic);
+ t->sequence = fio_swap32(t->sequence);
+ t->time = fio_swap64(t->time);
+ t->sector = fio_swap64(t->sector);
+ t->bytes = fio_swap32(t->bytes);
+ t->action = fio_swap32(t->action);
+ t->pid = fio_swap32(t->pid);
+ t->device = fio_swap32(t->device);
+ t->cpu = fio_swap32(t->cpu);
+ t->error = fio_swap16(t->error);
+ t->pdu_len = fio_swap16(t->pdu_len);
+}
+
+static bool t_is_write(struct blk_io_trace *t)
+{
+ return (t->action & BLK_TC_ACT(BLK_TC_WRITE | BLK_TC_DISCARD)) != 0;
+}
+
+static enum fio_ddir t_get_ddir(struct blk_io_trace *t)
+{
+ if (t->action & BLK_TC_ACT(BLK_TC_READ))
+ return DDIR_READ;
+ else if (t->action & BLK_TC_ACT(BLK_TC_WRITE))
+ return DDIR_WRITE;
+ else if (t->action & BLK_TC_ACT(BLK_TC_DISCARD))
+ return DDIR_TRIM;
+
+ return DDIR_INVAL;
+}
+
+static void depth_inc(struct blk_io_trace *t, int *depth)
+{
+ enum fio_ddir ddir;
+
+ ddir = t_get_ddir(t);
+ if (ddir != DDIR_INVAL)
+ depth[ddir]++;
+}
+
+static void depth_dec(struct blk_io_trace *t, int *depth)
+{
+ enum fio_ddir ddir;
+
+ ddir = t_get_ddir(t);
+ if (ddir != DDIR_INVAL)
+ depth[ddir]--;
+}
+
+static void depth_end(struct blk_io_trace *t, int *this_depth, int *depth)
+{
+ enum fio_ddir ddir = DDIR_INVAL;
+
+ ddir = t_get_ddir(t);
+ if (ddir != DDIR_INVAL) {
+ depth[ddir] = max(depth[ddir], this_depth[ddir]);
+ this_depth[ddir] = 0;
+ }
}
/*
* 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)
+bool load_blktrace(struct thread_data *td, const char *filename, int need_swap)
{
- unsigned long long ttime;
struct blk_io_trace t;
- unsigned long ios[2];
- int fd;
+ unsigned long ios[DDIR_RWDIR_SYNC_CNT] = { };
+ unsigned int rw_bs[DDIR_RWDIR_CNT] = { };
+ unsigned long skipped_writes;
+ struct fifo *fifo;
+ int fd, i, old_state, max_depth;
+ struct fio_file *f;
+ int this_depth[DDIR_RWDIR_CNT] = { };
+ int depth[DDIR_RWDIR_CNT] = { };
fd = open(filename, O_RDONLY);
if (fd < 0) {
td_verror(td, errno, "open blktrace file");
- return 1;
+ return false;
}
- ios[0] = ios[1] = 0;
- ttime = 0;
+ fifo = fifo_alloc(TRACE_FIFO_SIZE);
+
+ old_state = td_bump_runstate(td, TD_SETTING_UP);
+
+ td->o.size = 0;
+ skipped_writes = 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));
+ int ret = trace_fifo_get(td, fifo, fd, &t, sizeof(t));
- if (ret < 0) {
- td_verror(td, errno, "read blktrace file");
+ if (ret < 0)
goto err;
- } else if (!ret) {
+ else if (!ret)
+ break;
+ else if (ret < (int) sizeof(t)) {
+ log_err("fio: short fifo get\n");
break;
- } else if (ret != sizeof(t)) {
- log_err("fio: short read on blktrace file\n");
- goto err;
}
+ if (need_swap)
+ byteswap_trace(&t);
+
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);
+ log_err("fio: bad blktrace version %d\n",
+ t.magic & 0xff);
goto err;
}
- ret = discard_pdu(fd, &t);
- if (ret) {
- td_verror(td, ret, "blktrace lseek");
+ 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;
- handle_trace(td, &t, t.time - ttime, ios);
- ttime = t.time;
+ if ((t.action & BLK_TC_ACT(BLK_TC_NOTIFY)) == 0) {
+ if ((t.action & 0xffff) == __BLK_TA_QUEUE)
+ depth_inc(&t, this_depth);
+ else if (((t.action & 0xffff) == __BLK_TA_BACKMERGE) ||
+ ((t.action & 0xffff) == __BLK_TA_FRONTMERGE))
+ depth_dec(&t, this_depth);
+ else if ((t.action & 0xffff) == __BLK_TA_COMPLETE)
+ depth_end(&t, this_depth, depth);
+
+ if (t_is_write(&t) && read_only) {
+ skipped_writes++;
+ continue;
+ }
+ }
+
+ handle_trace(td, &t, ios, rw_bs);
} while (1);
+ for_each_file(td, f, i)
+ trace_add_open_close_event(td, f->fileno, FIO_LOG_CLOSE_FILE);
+
+ fifo_free(fifo);
close(fd);
- if (!ios[DDIR_READ] && !ios[DDIR_WRITE]) {
+ td_restore_runstate(td, old_state);
+
+ if (!td->files_index) {
+ log_err("fio: did not find replay device(s)\n");
+ return false;
+ }
+
+ /*
+ * For stacked devices, we don't always get a COMPLETE event so
+ * the depth grows to insane values. Limit it to something sane(r).
+ */
+ max_depth = 0;
+ for (i = 0; i < DDIR_RWDIR_CNT; i++) {
+ if (depth[i] > 1024)
+ depth[i] = 1024;
+ else if (!depth[i] && ios[i])
+ depth[i] = 1;
+ max_depth = max(depth[i], max_depth);
+ }
+
+ if (skipped_writes)
+ log_err("fio: %s skips replay of %lu writes due to read-only\n",
+ td->o.name, skipped_writes);
+
+ if (!ios[DDIR_READ] && !ios[DDIR_WRITE] && !ios[DDIR_TRIM] &&
+ !ios[DDIR_SYNC]) {
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;
+ return false;
+ }
+
+ td->o.td_ddir = 0;
+ if (ios[DDIR_READ]) {
+ td->o.td_ddir |= TD_DDIR_READ;
+ td->o.max_bs[DDIR_READ] = rw_bs[DDIR_READ];
+ }
+ if (ios[DDIR_WRITE]) {
+ td->o.td_ddir |= TD_DDIR_WRITE;
+ td->o.max_bs[DDIR_WRITE] = rw_bs[DDIR_WRITE];
+ }
+ if (ios[DDIR_TRIM]) {
+ td->o.td_ddir |= TD_DDIR_TRIM;
+ td->o.max_bs[DDIR_TRIM] = rw_bs[DDIR_TRIM];
+ }
/*
* We need to do direct/raw ios to the device, to avoid getting
- * read-ahead in our way.
+ * read-ahead in our way. But only do so if the minimum block size
+ * is a multiple of 4k, otherwise we don't know if it's safe to do so.
*/
- td->o.odirect = 1;
+ if (!fio_option_is_set(&td->o, odirect) && !(td_min_bs(td) & 4095))
+ td->o.odirect = 1;
- return 0;
+ /*
+ * If depth wasn't manually set, use probed depth
+ */
+ if (!fio_option_is_set(&td->o, iodepth))
+ td->o.iodepth = td->o.iodepth_low = max_depth;
+
+ return true;
err:
close(fd);
- return 1;
+ fifo_free(fifo);
+ return false;
+}
+
+static int init_merge_param_list(fio_fp64_t *vals, struct blktrace_cursor *bcs,
+ int nr_logs, int def, size_t off)
+{
+ int i = 0, len = 0;
+
+ while (len < FIO_IO_U_LIST_MAX_LEN && vals[len].u.f != 0.0)
+ len++;
+
+ if (len && len != nr_logs)
+ return len;
+
+ for (i = 0; i < nr_logs; i++) {
+ int *val = (int *)((char *)&bcs[i] + off);
+ *val = def;
+ if (len)
+ *val = (int)vals[i].u.f;
+ }
+
+ return 0;
+
+}
+
+static int find_earliest_io(struct blktrace_cursor *bcs, int nr_logs)
+{
+ __u64 time = ~(__u64)0;
+ int idx = 0, i;
+
+ for (i = 0; i < nr_logs; i++) {
+ if (bcs[i].t.time < time) {
+ time = bcs[i].t.time;
+ idx = i;
+ }
+ }
+
+ return idx;
+}
+
+static void merge_finish_file(struct blktrace_cursor *bcs, int i, int *nr_logs)
+{
+ bcs[i].iter++;
+ if (bcs[i].iter < bcs[i].nr_iter) {
+ lseek(bcs[i].fd, 0, SEEK_SET);
+ return;
+ }
+
+ *nr_logs -= 1;
+
+ /* close file */
+ fifo_free(bcs[i].fifo);
+ close(bcs[i].fd);
+
+ /* keep active files contiguous */
+ memmove(&bcs[i], &bcs[*nr_logs], sizeof(bcs[i]));
+}
+
+static int read_trace(struct thread_data *td, struct blktrace_cursor *bc)
+{
+ int ret = 0;
+ struct blk_io_trace *t = &bc->t;
+
+read_skip:
+ /* read an io trace */
+ ret = trace_fifo_get(td, bc->fifo, bc->fd, t, sizeof(*t));
+ if (ret < 0) {
+ return ret;
+ } else if (!ret) {
+ if (!bc->length)
+ bc->length = bc->t.time;
+ return ret;
+ } else if (ret < (int) sizeof(*t)) {
+ log_err("fio: short fifo get\n");
+ return -1;
+ }
+
+ if (bc->swap)
+ byteswap_trace(t);
+
+ /* skip over actions that fio does not care about */
+ if ((t->action & 0xffff) != __BLK_TA_QUEUE ||
+ t_get_ddir(t) == DDIR_INVAL) {
+ ret = discard_pdu(td, bc->fifo, bc->fd, t);
+ if (ret < 0) {
+ td_verror(td, -ret, "blktrace lseek");
+ return ret;
+ } else if (t->pdu_len != ret) {
+ log_err("fio: discarded %d of %d\n", ret,
+ t->pdu_len);
+ return -1;
+ }
+ goto read_skip;
+ }
+
+ t->time = (t->time + bc->iter * bc->length) * bc->scalar / 100;
+
+ return ret;
+}
+
+static int write_trace(FILE *fp, struct blk_io_trace *t)
+{
+ /* pdu is not used so just write out only the io trace */
+ t->pdu_len = 0;
+ return fwrite((void *)t, sizeof(*t), 1, fp);
+}
+
+int merge_blktrace_iologs(struct thread_data *td)
+{
+ int nr_logs = get_max_str_idx(td->o.read_iolog_file);
+ struct blktrace_cursor *bcs = malloc(sizeof(struct blktrace_cursor) *
+ nr_logs);
+ struct blktrace_cursor *bc;
+ FILE *merge_fp;
+ char *str, *ptr, *name, *merge_buf;
+ int i, ret;
+
+ ret = init_merge_param_list(td->o.merge_blktrace_scalars, bcs, nr_logs,
+ 100, offsetof(struct blktrace_cursor,
+ scalar));
+ if (ret) {
+ log_err("fio: merge_blktrace_scalars(%d) != nr_logs(%d)\n",
+ ret, nr_logs);
+ goto err_param;
+ }
+
+ ret = init_merge_param_list(td->o.merge_blktrace_iters, bcs, nr_logs,
+ 1, offsetof(struct blktrace_cursor,
+ nr_iter));
+ if (ret) {
+ log_err("fio: merge_blktrace_iters(%d) != nr_logs(%d)\n",
+ ret, nr_logs);
+ goto err_param;
+ }
+
+ /* setup output file */
+ merge_fp = fopen(td->o.merge_blktrace_file, "w");
+ merge_buf = malloc(128 * 1024);
+ if (!merge_buf)
+ goto err_out_file;
+ ret = setvbuf(merge_fp, merge_buf, _IOFBF, 128 * 1024);
+ if (ret)
+ goto err_merge_buf;
+
+ /* setup input files */
+ str = ptr = strdup(td->o.read_iolog_file);
+ nr_logs = 0;
+ for (i = 0; (name = get_next_str(&ptr)) != NULL; i++) {
+ bcs[i].fd = open(name, O_RDONLY);
+ if (bcs[i].fd < 0) {
+ log_err("fio: could not open file: %s\n", name);
+ ret = bcs[i].fd;
+ free(str);
+ goto err_file;
+ }
+ bcs[i].fifo = fifo_alloc(TRACE_FIFO_SIZE);
+ nr_logs++;
+
+ if (!is_blktrace(name, &bcs[i].swap)) {
+ log_err("fio: file is not a blktrace: %s\n", name);
+ free(str);
+ goto err_file;
+ }
+
+ ret = read_trace(td, &bcs[i]);
+ if (ret < 0) {
+ free(str);
+ goto err_file;
+ } else if (!ret) {
+ merge_finish_file(bcs, i, &nr_logs);
+ i--;
+ }
+ }
+ free(str);
+
+ /* merge files */
+ while (nr_logs) {
+ i = find_earliest_io(bcs, nr_logs);
+ bc = &bcs[i];
+ /* skip over the pdu */
+ ret = discard_pdu(td, bc->fifo, bc->fd, &bc->t);
+ if (ret < 0) {
+ td_verror(td, -ret, "blktrace lseek");
+ goto err_file;
+ } else if (bc->t.pdu_len != ret) {
+ log_err("fio: discarded %d of %d\n", ret,
+ bc->t.pdu_len);
+ goto err_file;
+ }
+
+ ret = write_trace(merge_fp, &bc->t);
+ ret = read_trace(td, bc);
+ if (ret < 0)
+ goto err_file;
+ else if (!ret)
+ merge_finish_file(bcs, i, &nr_logs);
+ }
+
+ /* set iolog file to read from the newly merged file */
+ td->o.read_iolog_file = td->o.merge_blktrace_file;
+ ret = 0;
+
+err_file:
+ /* cleanup */
+ for (i = 0; i < nr_logs; i++) {
+ fifo_free(bcs[i].fifo);
+ close(bcs[i].fd);
+ }
+err_merge_buf:
+ free(merge_buf);
+err_out_file:
+ fflush(merge_fp);
+ fclose(merge_fp);
+err_param:
+ free(bcs);
+
+ return ret;
}