[PATCH] Add support for specifying read/write mix workloads better
Added options:
- rwmixcycle=x, use x msecs as the cycle period for read/write switches
- rwmixread=x, x% of ios will be reads
- rwmixwrite=x, x% of ios will be writes
Last given of the latter two will override the first.
diff --git a/README b/README
index 8b84a08..3d59337 100644
--- a/README
+++ b/README
@@ -41,6 +41,13 @@
directory=x Use 'x' as the top level directory for storing files
rw=x 'x' may be: read, randread, write, randwrite,
rw (read-write mix), randrw (read-write random mix)
+ rwmixcycle=x Base cycle for switching between read and write
+ in msecs.
+ rwmixread=x 'x' percentage of rw mix ios will be reads. If
+ rwmixwrite is also given, the last of the two will
+ be used if they don't add up to 100%.
+ rwmixwrite=x 'x' percentage of rw mix ios will be writes. See
+ rwmixread.
size=x Set file size to x bytes (x string can include k/m/g)
ioengine=x 'x' may be: aio/libaio/linuxaio for Linux aio,
posixaio for POSIX aio, sync for regular read/write io,
diff --git a/fio-ini.c b/fio-ini.c
index f529757..0fec342 100644
--- a/fio-ini.c
+++ b/fio-ini.c
@@ -36,6 +36,8 @@
#define DEF_FILE_SIZE (1024 * 1024 * 1024UL)
#define DEF_ZONE_SIZE (0)
#define DEF_ZONE_SKIP (0)
+#define DEF_RWMIX_CYCLE (500)
+#define DEF_RWMIX_READ (50)
static char fio_version_string[] = "fio 1.3";
@@ -282,7 +284,7 @@
int init_random_state(struct thread_data *td)
{
- unsigned long seed;
+ unsigned long seeds[4];
int fd, num_maps, blocks;
fd = open("/dev/urandom", O_RDONLY);
@@ -291,7 +293,7 @@
return 1;
}
- if (read(fd, &seed, sizeof(seed)) < (int) sizeof(seed)) {
+ if (read(fd, seeds, sizeof(seeds)) < (int) sizeof(seeds)) {
td_verror(td, EIO);
close(fd);
return 1;
@@ -299,14 +301,15 @@
close(fd);
- srand48_r(seed, &td->bsrange_state);
- srand48_r(seed, &td->verify_state);
+ srand48_r(seeds[0], &td->bsrange_state);
+ srand48_r(seeds[1], &td->verify_state);
+ srand48_r(seeds[2], &td->rwmix_state);
if (td->sequential)
return 0;
if (repeatable)
- seed = DEF_RANDSEED;
+ seeds[3] = DEF_RANDSEED;
blocks = (td->io_size + td->min_bs - 1) / td->min_bs;
num_maps = blocks / BLOCKS_PER_MAP;
@@ -314,7 +317,7 @@
td->num_maps = num_maps;
memset(td->file_map, 0, num_maps * sizeof(long));
- srand48_r(seed, &td->random_state);
+ srand48_r(seeds[3], &td->random_state);
return 0;
}
@@ -640,7 +643,7 @@
int parse_jobs_ini(char *file)
{
- unsigned int prioclass, prio, cpu, global;
+ unsigned int prioclass, prio, cpu, global, il;
unsigned long long ull;
unsigned long ul1, ul2;
struct thread_data *td;
@@ -781,6 +784,24 @@
fgetpos(f, &off);
continue;
}
+ if (!check_int(p, "rwmixcycle", &td->rwmixcycle)) {
+ fgetpos(f, &off);
+ continue;
+ }
+ if (!check_int(p, "rwmixread", &il)) {
+ if (il > 100)
+ il = 100;
+ td->rwmixread = il;
+ fgetpos(f, &off);
+ continue;
+ }
+ if (!check_int(p, "rwmixwrite", &il)) {
+ if (il > 100)
+ il = 100;
+ td->rwmixread = 100 - il;
+ fgetpos(f, &off);
+ continue;
+ }
if (!check_range(p, "bsrange", &ul1, &ul2)) {
if (ul1 > ul2) {
td->max_bs = ul1;
@@ -914,6 +935,8 @@
def_thread.stonewall = DEF_STONEWALL;
def_thread.numjobs = DEF_NUMJOBS;
def_thread.use_thread = DEF_USE_THREAD;
+ def_thread.rwmixcycle = DEF_RWMIX_CYCLE;
+ def_thread.rwmixread = DEF_RWMIX_READ;
#ifdef FIO_HAVE_DISK_UTIL
def_thread.do_disk_util = 1;
#endif
diff --git a/fio.c b/fio.c
index 51cd153..c5e4f3c 100644
--- a/fio.c
+++ b/fio.c
@@ -545,44 +545,32 @@
memcpy(hdr->md5_digest, md5_ctx.hash, sizeof(md5_ctx.hash));
}
-unsigned int hweight32(unsigned int w)
-{
- unsigned int res = w - ((w >> 1) & 0x55555555);
-
- res = (res & 0x33333333) + ((res >> 2) & 0x33333333);
- res = (res + (res >> 4)) & 0x0F0F0F0F;
- res = res + (res >> 8);
-
- return (res + (res >> 16)) & 0x000000FF;
-}
-
-unsigned long hweight64(unsigned long long w)
-{
-#if __WORDSIZE == 32
- return hweight32((unsigned int)(w >> 32)) + hweight32((unsigned int)w);
-#elif __WORDSIZE == 64
- unsigned long long v = w - ((w >> 1) & 0x5555555555555555ul);
-
- v = (v & 0x3333333333333333ul) + ((v >> 2) & 0x3333333333333333ul);
- v = (v + (v >> 4)) & 0x0F0F0F0F0F0F0F0Ful;
- v = v + (v >> 8);
- v = v + (v >> 16);
-
- return (v + (v >> 32)) & 0x00000000000000FFul;
-#else
-#error __WORDSIZE not defined
-#endif
-}
-
static int get_rw_ddir(struct thread_data *td)
{
- /*
- * perhaps cheasy, but use the hamming weight of the position
- * as a randomizer for data direction.
- */
- if (td_rw(td))
- return hweight64(td->last_pos) & 1;
- else if (td_read(td))
+ if (td_rw(td)) {
+ struct timeval now;
+ unsigned long elapsed;
+
+ gettimeofday(&now, NULL);
+ elapsed = mtime_since_now(&td->rwmix_switch);
+
+ /*
+ * Check if it's time to seed a new data direction.
+ */
+ if (elapsed >= td->rwmixcycle) {
+ unsigned long v;
+ long r;
+
+ lrand48_r(&td->random_state, &r);
+ v = 100UL * r / (unsigned long) (RAND_MAX + 1.0);
+ if (v < td->rwmixread)
+ td->rwmix_ddir = DDIR_READ;
+ else
+ td->rwmix_ddir = DDIR_WRITE;
+ memcpy(&td->rwmix_switch, &now, sizeof(now));
+ }
+ return td->rwmix_ddir;
+ } else if (td_read(td))
return DDIR_READ;
else
return DDIR_WRITE;
diff --git a/fio.h b/fio.h
index 4f87fb7..dbf476e 100644
--- a/fio.h
+++ b/fio.h
@@ -151,6 +151,8 @@
os_cpu_mask_t cpumask;
unsigned int jobnum;
unsigned int iolog;
+ unsigned int rwmixcycle;
+ unsigned int rwmixread;
char iolog_file[256];
@@ -222,6 +224,10 @@
unsigned int do_disk_util;
unsigned int override_sync;
+ struct drand48_data rwmix_state;
+ struct timeval rwmix_switch;
+ int rwmix_ddir;
+
struct list_head io_hist_list;
struct list_head io_log_list;
};