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authorJens Axboe <jaxboe@fusionio.com>2011-01-27 22:25:29 +0100
committerJens Axboe <jaxboe@fusionio.com>2011-01-27 22:25:29 +0100
commit0ce8b119b65849e537cab628a176a0ec4238aab0 (patch)
treeda9bf8226544273ecf338b636760401b2e28229b
parent0a560893bb20b06bf6c15dd9213cf383cfbcf28f (diff)
downloadfio-0ce8b119b65849e537cab628a176a0ec4238aab0.tar.gz
fio-0ce8b119b65849e537cab628a176a0ec4238aab0.tar.bz2
Fix end-of-job slowdown for random IO with a random map
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
-rw-r--r--arch/arch-x86_64.h4
-rw-r--r--file.h6
-rw-r--r--filesetup.c2
-rw-r--r--fio.h2
-rw-r--r--io_u.c45
-rw-r--r--lib/ffz.h10
6 files changed, 46 insertions, 23 deletions
diff --git a/arch/arch-x86_64.h b/arch/arch-x86_64.h
index 6dbeee06..f2dcf497 100644
--- a/arch/arch-x86_64.h
+++ b/arch/arch-x86_64.h
@@ -33,9 +33,9 @@
#define read_barrier() __asm__ __volatile__("lfence":::"memory")
#define write_barrier() __asm__ __volatile__("sfence":::"memory")
-static inline unsigned int arch_ffz(unsigned int bitmask)
+static inline unsigned long arch_ffz(unsigned long bitmask)
{
- __asm__("bsfl %1,%0" :"=r" (bitmask) :"r" (~bitmask));
+ __asm__("bsf %1,%0" :"=r" (bitmask) :"r" (~bitmask));
return bitmask;
}
diff --git a/file.h b/file.h
index 7948a412..04c0d453 100644
--- a/file.h
+++ b/file.h
@@ -96,9 +96,10 @@ struct fio_file {
/*
* block map for random io
*/
- unsigned int *file_map;
+ unsigned long *file_map;
unsigned int num_maps;
unsigned int last_free_lookup;
+ unsigned int failed_rands;
int references;
enum fio_file_flags flags;
@@ -158,11 +159,12 @@ extern void free_release_files(struct thread_data *);
static inline void fio_file_reset(struct fio_file *f)
{
f->last_free_lookup = 0;
+ f->failed_rands = 0;
f->last_pos = f->file_offset;
f->last_start = -1ULL;
f->file_pos = -1ULL;
if (f->file_map)
- memset(f->file_map, 0, f->num_maps * sizeof(int));
+ memset(f->file_map, 0, f->num_maps * sizeof(unsigned long));
}
#endif
diff --git a/filesetup.c b/filesetup.c
index d0505064..0454cc40 100644
--- a/filesetup.c
+++ b/filesetup.c
@@ -812,7 +812,7 @@ int init_random_map(struct thread_data *td)
(unsigned long long) td->o.rw_min_bs;
num_maps = (blocks + BLOCKS_PER_MAP - 1) /
(unsigned long long) BLOCKS_PER_MAP;
- f->file_map = smalloc(num_maps * sizeof(int));
+ f->file_map = smalloc(num_maps * sizeof(unsigned long));
if (f->file_map) {
f->num_maps = num_maps;
continue;
diff --git a/fio.h b/fio.h
index d2cca118..08f17331 100644
--- a/fio.h
+++ b/fio.h
@@ -531,7 +531,7 @@ static inline void fio_ro_check(struct thread_data *td, struct io_u *io_u)
assert(!(io_u->ddir == DDIR_WRITE && !td_write(td)));
}
-#define BLOCKS_PER_MAP (8 * sizeof(int))
+#define BLOCKS_PER_MAP (8 * sizeof(unsigned long))
#define TO_MAP_BLOCK(f, b) (b)
#define RAND_MAP_IDX(f, b) (TO_MAP_BLOCK(f, b) / BLOCKS_PER_MAP)
#define RAND_MAP_BIT(f, b) (TO_MAP_BLOCK(f, b) & (BLOCKS_PER_MAP - 1))
diff --git a/io_u.c b/io_u.c
index 1a45706f..5a3ca744 100644
--- a/io_u.c
+++ b/io_u.c
@@ -30,7 +30,7 @@ static int random_map_free(struct fio_file *f, const unsigned long long block)
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 @@ static void mark_random_map(struct thread_data *td, struct io_u *io_u)
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 @@ static void mark_random_map(struct thread_data *td, struct io_u *io_u)
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 unsigned long long last_block(struct thread_data *td, struct fio_file *f,
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 @@ static int get_next_free_block(struct thread_data *td, struct fio_file *f,
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 @@ static int get_next_rand_offset(struct thread_data *td, struct fio_file *f,
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 @@ static int get_next_rand_offset(struct thread_data *td, struct fio_file *f,
* 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 @@ static int get_next_rand_offset(struct thread_data *td, struct fio_file *f,
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 @@ static int get_next_rand_offset(struct thread_data *td, struct fio_file *f,
* 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,
diff --git a/lib/ffz.h b/lib/ffz.h
index e17a2e9c..eef612d1 100644
--- a/lib/ffz.h
+++ b/lib/ffz.h
@@ -1,10 +1,16 @@
#ifndef FIO_FFZ_H
#define FIO_FFZ_H
-static inline int __ffs(int word)
+static inline int __ffs(unsigned long word)
{
int r = 0;
+#if BITS_PER_LONG == 64
+ if ((word & 0xffffffff) == 0) {
+ r += 32;
+ word >>= 32;
+ }
+#endif
if (!(word & 0xffff)) {
word >>= 16;
r += 16;
@@ -29,7 +35,7 @@ static inline int __ffs(int word)
return r;
}
-static inline int ffz(unsigned int bitmask)
+static inline int ffz(unsigned long bitmask)
{
return __ffs(~bitmask);
}