Fix end-of-job slowdown for random IO with a random map
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
diff --git a/io_u.c b/io_u.c
index 1a45706..5a3ca74 100644
--- a/io_u.c
+++ b/io_u.c
@@ -30,7 +30,7 @@
dprint(FD_RANDOM, "free: b=%llu, idx=%u, bit=%u\n", block, idx, bit);
- return (f->file_map[idx] & (1 << bit)) == 0;
+ return (f->file_map[idx] & (1UL << bit)) == 0;
}
/*
@@ -50,8 +50,8 @@
busy_check = !(io_u->flags & IO_U_F_BUSY_OK);
while (nr_blocks) {
- unsigned int this_blocks, mask;
unsigned int idx, bit;
+ unsigned long mask, this_blocks;
/*
* If we have a mixed random workload, we may
@@ -75,9 +75,9 @@
do {
if (this_blocks == BLOCKS_PER_MAP)
- mask = -1U;
+ mask = -1UL;
else
- mask = ((1U << this_blocks) - 1) << bit;
+ mask = ((1UL << this_blocks) - 1) << bit;
if (!(f->file_map[idx] & mask))
break;
@@ -126,7 +126,7 @@
static int get_next_free_block(struct thread_data *td, struct fio_file *f,
enum fio_ddir ddir, unsigned long long *b)
{
- unsigned long long min_bs = td->o.rw_min_bs, lastb;
+ unsigned long long block, min_bs = td->o.rw_min_bs, lastb;
int i;
lastb = last_block(td, f, ddir);
@@ -134,18 +134,19 @@
return 1;
i = f->last_free_lookup;
- *b = (i * BLOCKS_PER_MAP);
- while ((*b) * min_bs < f->real_file_size &&
- (*b) * min_bs < f->io_size) {
- if (f->file_map[i] != (unsigned int) -1) {
- *b += ffz(f->file_map[i]);
- if (*b > lastb)
+ block = i * BLOCKS_PER_MAP;
+ while (block * min_bs < f->real_file_size &&
+ block * min_bs < f->io_size) {
+ if (f->file_map[i] != -1UL) {
+ block += ffz(f->file_map[i]);
+ if (block > lastb)
break;
f->last_free_lookup = i;
+ *b = block;
return 0;
}
- *b += BLOCKS_PER_MAP;
+ block += BLOCKS_PER_MAP;
i++;
}
@@ -163,6 +164,9 @@
if (!lastb)
return 1;
+ if (f->failed_rands >= 200)
+ goto ffz;
+
do {
r = os_random_long(&td->random_state);
dprint(FD_RANDOM, "off rand %llu\n", r);
@@ -172,18 +176,21 @@
* if we are not maintaining a random map, we are done.
*/
if (!file_randommap(td, f))
- return 0;
+ goto ret_good;
/*
* calculate map offset and check if it's free
*/
if (random_map_free(f, *b))
- return 0;
+ goto ret_good;
dprint(FD_RANDOM, "get_next_rand_offset: offset %llu busy\n",
*b);
} while (--loops);
+ if (!f->failed_rands++)
+ f->last_free_lookup = 0;
+
/*
* we get here, if we didn't suceed in looking up a block. generate
* a random start offset into the filemap, and find the first free
@@ -194,7 +201,7 @@
f->last_free_lookup = (f->num_maps - 1) *
(r / (OS_RAND_MAX + 1.0));
if (!get_next_free_block(td, f, ddir, b))
- return 0;
+ goto ret;
r = os_random_long(&td->random_state);
} while (--loops);
@@ -203,7 +210,15 @@
* that didn't work either, try exhaustive search from the start
*/
f->last_free_lookup = 0;
+ffz:
+ if (!get_next_free_block(td, f, ddir, b))
+ return 0;
+ f->last_free_lookup = 0;
return get_next_free_block(td, f, ddir, b);
+ret_good:
+ f->failed_rands = 0;
+ret:
+ return 0;
}
static int get_next_rand_block(struct thread_data *td, struct fio_file *f,