Basic support for dedupe
This adds and option, dedupe_percentage, that controls how many of
the write IO buffers are identical. For instance, if this is set:
dedupe_percentage=70
then 70% of the write IO buffers will have identical contents. The
specific contents are, as before, controlled by the various options
that set buffer contents or buffer compressibility.
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/lib/rand.h b/lib/rand.h
index d62ebe5..8c35ab1 100644
--- a/lib/rand.h
+++ b/lib/rand.h
@@ -7,6 +7,14 @@
unsigned int s1, s2, s3;
};
+static inline void frand_copy(struct frand_state *dst,
+ struct frand_state *src)
+{
+ dst->s1 = src->s1;
+ dst->s2 = src->s2;
+ dst->s3 = src->s3;
+}
+
static inline unsigned int __rand(struct frand_state *state)
{
#define TAUSWORTHE(s,a,b,c,d) ((s&c)<<d) ^ (((s <<a) ^ s)>>b)