The following changes since commit fdba6ac393728b3f743013a6517a987fda79bd1a:
Remove default setting of clocksource (2010-03-24 13:44:34 +0100)
are available in the git repository at:
git://git.kernel.dk/fio.git master
Jens Axboe (8):
Fix typo in bandwidth log command line option
Keep the global command line bw/lat logs separate from per job logs
First step at speeding up io_u rand refill
Merge branch 'master' of ssh://brick.kernel.dk/data/git/fio
Remember to prime the random generator
"Expand" random number from 32-bit to 64-bit when necessary
Add documentation for the random number generator
Only use true random generator for initial seed
Makefile | 2 +
Makefile.FreeBSD | 2 +
Makefile.mac | 2 +
Makefile.solaris | 2 +
fio.c | 2 +
init.c | 5 +---
io_u.c | 10 ++++++++-
lib/rand.c | 59 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
lib/rand.h | 23 +++++++++++++++++++++
9 files changed, 102 insertions(+), 5 deletions(-)
create mode 100644 lib/rand.c
create mode 100644 lib/rand.h
---
Diff of recent changes:
diff --git a/Makefile b/Makefile
index 12042f4..837f421 100644
--- a/Makefile
+++ b/Makefile
@@ -9,6 +9,8 @@ OBJS = gettime.o fio.o ioengines.o init.o stat.o log.o time.o filesetup.o \
rbtree.o diskutil.o fifo.o blktrace.o smalloc.o filehash.o helpers.o \
cgroup.o profile.o debug.o
+OBJS += lib/rand.o
+
OBJS += crc/crc7.o
OBJS += crc/crc16.o
OBJS += crc/crc32.o
diff --git a/Makefile.FreeBSD b/Makefile.FreeBSD
index deae03d..3c59a99 100644
--- a/Makefile.FreeBSD
+++ b/Makefile.FreeBSD
@@ -8,6 +8,8 @@ OBJS = gettime.o fio.o ioengines.o init.o stat.o log.o time.o filesetup.o \
eta.o verify.o memory.o io_u.o parse.o mutex.o options.o \
rbtree.o smalloc.o filehash.o helpers.o profile.o debug.o
+OBJS += lib/rand.o
+
OBJS += crc/crc7.o
OBJS += crc/crc16.o
OBJS += crc/crc32.o
diff --git a/Makefile.mac b/Makefile.mac
index a726546..fe84297 100644
--- a/Makefile.mac
+++ b/Makefile.mac
@@ -8,6 +8,8 @@ OBJS = gettime.o fio.o ioengines.o init.o stat.o log.o time.o filesetup.o \
eta.o verify.o memory.o io_u.o parse.o mutex.o options.o \
rbtree.o smalloc.o filehash.o helpers.o profile.o debug.o
+OBJS += lib/rand.o
+
OBJS += crc/crc7.o
OBJS += crc/crc16.o
OBJS += crc/crc32.o
diff --git a/Makefile.solaris b/Makefile.solaris
index 0ec6d73..49a4ef9 100644
--- a/Makefile.solaris
+++ b/Makefile.solaris
@@ -7,6 +7,8 @@ OBJS = gettime.o fio.o ioengines.o init.o stat.o log.o time.o filesetup.o \
rbtree.o fifo.o smalloc.o filehash.o lib/strsep.o helpers.o solaris.o \
profile.o debug.o
+OBJS += lib/rand.o
+
OBJS += crc/crc7.o
OBJS += crc/crc16.o
OBJS += crc/crc32.o
diff --git a/fio.c b/fio.c
index dfda268..03dc6cc 100644
--- a/fio.c
+++ b/fio.c
@@ -41,6 +41,7 @@
#include "diskutil.h"
#include "cgroup.h"
#include "profile.h"
+#include "lib/rand.h"
unsigned long page_mask;
unsigned long page_size;
@@ -1636,6 +1637,7 @@ int main(int argc, char *argv[])
long ps;
sinit();
+ init_rand(&__fio_rand_state);
/*
* We need locale for number printing, if it isn't set then just
diff --git a/init.c b/init.c
index 4d0a906..69941b2 100644
--- a/init.c
+++ b/init.c
@@ -881,9 +881,6 @@ static int fill_def_thread(void)
fio_fill_default_options(&def_thread);
def_thread.o.timeout = def_timeout;
- def_thread.o.write_bw_log = write_bw_log;
- def_thread.o.write_lat_log = write_lat_log;
-
return 0;
}
@@ -1076,7 +1073,7 @@ static int parse_cmd_line(int argc, char *argv[])
case 'l':
write_lat_log = 1;
break;
- case 'w':
+ case 'b':
write_bw_log = 1;
break;
case 'o':
diff --git a/io_u.c b/io_u.c
index afc90de..23037f1 100644
--- a/io_u.c
+++ b/io_u.c
@@ -8,6 +8,7 @@
#include "fio.h"
#include "hash.h"
#include "verify.h"
+#include "lib/rand.h"
struct io_completion_data {
int nr; /* input */
@@ -1216,9 +1217,16 @@ void io_u_fill_buffer(struct thread_data *td, struct io_u *io_u,
long *ptr = io_u->buf;
if (!td->o.zero_buffers) {
+ unsigned long r = __rand(&__fio_rand_state);
+
+ if (sizeof(int) != sizeof(*ptr))
+ r *= (unsigned long) __rand(&__fio_rand_state);
+
while ((void *) ptr - io_u->buf < max_bs) {
- *ptr = rand() * GOLDEN_RATIO_PRIME;
+ *ptr = r;
ptr++;
+ r *= GOLDEN_RATIO_PRIME;
+ r >>= 3;
}
} else
memset(ptr, 0, max_bs);
diff --git a/lib/rand.c b/lib/rand.c
new file mode 100644
index 0000000..cecc4c2
--- /dev/null
+++ b/lib/rand.c
@@ -0,0 +1,59 @@
+/*
+ This is a maximally equidistributed combined Tausworthe generator
+ based on code from GNU Scientific Library 1.5 (30 Jun 2004)
+
+ x_n = (s1_n ^ s2_n ^ s3_n)
+
+ s1_{n+1} = (((s1_n & 4294967294) <<12) ^ (((s1_n <<13) ^ s1_n) >>19))
+ s2_{n+1} = (((s2_n & 4294967288) << 4) ^ (((s2_n << 2) ^ s2_n) >>25))
+ s3_{n+1} = (((s3_n & 4294967280) <<17) ^ (((s3_n << 3) ^ s3_n) >>11))
+
+ The period of this generator is about 2^88.
+
+ From: P. L'Ecuyer, "Maximally Equidistributed Combined Tausworthe
+ Generators", Mathematics of Computation, 65, 213 (1996), 203--213.
+
+ This is available on the net from L'Ecuyer's home page,
+
+ http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme.ps
+ ftp://ftp.iro.umontreal.ca/pub/simulation/lecuyer/papers/tausme.ps
+
+ There is an erratum in the paper "Tables of Maximally
+ Equidistributed Combined LFSR Generators", Mathematics of
+ Computation, 68, 225 (1999), 261--269:
+ http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme2.ps
+
+ ... the k_j most significant bits of z_j must be non-
+ zero, for each j. (Note: this restriction also applies to the
+ computer code given in [4], but was mistakenly not mentioned in
+ that paper.)
+
+ This affects the seeding procedure by imposing the requirement
+ s1 > 1, s2 > 7, s3 > 15.
+
+*/
+
+#include "rand.h"
+
+struct frand_state __fio_rand_state;
+
+static inline int __seed(unsigned int x, unsigned int m)
+{
+ return (x < m) ? x + m : x;
+}
+
+void init_rand(struct frand_state *state)
+{
+#define LCG(x) ((x) * 69069) /* super-duper LCG */
+
+ state->s1 = __seed(LCG((2^31) + (2^17) + (2^7)), 1);
+ state->s2 = __seed(LCG(state->s1), 7);
+ state->s3 = __seed(LCG(state->s2), 15);
+
+ __rand(state);
+ __rand(state);
+ __rand(state);
+ __rand(state);
+ __rand(state);
+ __rand(state);
+}
diff --git a/lib/rand.h b/lib/rand.h
new file mode 100644
index 0000000..363e7b6
--- /dev/null
+++ b/lib/rand.h
@@ -0,0 +1,23 @@
+#ifndef FIO_RAND_H
+#define FIO_RAND_H
+
+struct frand_state {
+ unsigned int s1, s2, s3;
+};
+
+extern struct frand_state __fio_rand_state;
+
+static inline unsigned int __rand(struct frand_state *state)
+{
+#define TAUSWORTHE(s,a,b,c,d) ((s&c)<<d) ^ (((s <<a) ^ s)>>b)
+
+ state->s1 = TAUSWORTHE(state->s1, 13, 19, 4294967294UL, 12);
+ state->s2 = TAUSWORTHE(state->s2, 2, 25, 4294967288UL, 4);
+ state->s3 = TAUSWORTHE(state->s3, 3, 11, 4294967280UL, 17);
+
+ return (state->s1 ^ state->s2 ^ state->s3);
+}
+
+extern void init_rand(struct frand_state *);
+
+#endif
--
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