Hi.
I'm now trying to run multi-threaded log replay, and noticed
all threads are accessing same sector on a disk. Of course,
this is an expected behavior of "replay".
But since I also wanted to have each thread accessing different
parts of the disk to increase a load, but still following the
access pattern of the original, I added "replay_rebase" option to
shift offset of IO request for each thread.
Althrough there's "1/2" in the subject, this patch is complete
by itself. Next one (2/2) is related, but handles different issue.
Signed-off-by: Taisuke Yamada <tai@xxxxxxxxxxxx>
---
fio.h | 1 +
log.c | 2 +-
options.c | 8 ++++++++
3 files changed, 10 insertions(+), 1 deletions(-)
diff --git a/fio.h b/fio.h
index 6eb270d..b28e0ae 100644
--- a/fio.h
+++ b/fio.h
@@ -358,6 +358,7 @@ struct thread_options {
unsigned int gtod_offload;
enum fio_cs clocksource;
unsigned int no_stall;
+ unsigned int replay_rebase;
unsigned int trim_percentage;
unsigned int trim_batch;
unsigned int trim_zero;
diff --git a/log.c b/log.c
index f962864..57fc0f4 100644
--- a/log.c
+++ b/log.c
@@ -129,7 +129,7 @@ int read_iolog_get(struct thread_data *td, struct io_u *io_u)
io_u->ddir = ipo->ddir;
if (ipo->ddir != DDIR_WAIT) {
- io_u->offset = ipo->offset;
+ io_u->offset = ipo->offset + td->o.replay_rebase * td->thread_number;
io_u->buflen = ipo->len;
io_u->file = td->files[ipo->fileno];
get_file(io_u->file);
diff --git a/options.c b/options.c
index 74c24d0..aba14b1 100644
--- a/options.c
+++ b/options.c
@@ -1654,6 +1654,14 @@ static struct fio_option options[FIO_MAX_OPTS] = {
.help = "Replay all I/O onto this device, regardless of trace device",
},
{
+ .name = "replay_rebase",
+ .type = FIO_OPT_INT,
+ .off1 = td_var_offset(replay_rebase),
+ .def = "0",
+ .parent = "read_iolog",
+ .help = "Apply given offset for IO replay. Mainly for parallel replay.",
+ },
+ {
.name = "exec_prerun",
.type = FIO_OPT_STR_STORE,
.off1 = td_var_offset(exec_prerun),
