dedupe: allow to generate dedupe buffers from working set

[fio.git] / dedupe.c

diff --git a/dedupe.c b/dedupe.c
new file mode 100644 (file)
index 0000000..043a376
--- /dev/null
+++ b/dedupe.c
@@ -0,0 +1,28 @@
+#include "fio.h"
+
+int init_dedupe_working_set_seeds(struct thread_data *td)
+{
+       unsigned long long i;
+       struct frand_state dedupe_working_set_state = {0};
+
+       if (!td->o.dedupe_percentage || !(td->o.dedupe_mode == DEDUPE_MODE_WORKING_SET))
+               return 0;
+
+       /*
+        * The dedupe working set keeps seeds of unique data (generated by buf_state).
+        * Dedupe-ed pages will be generated using those seeds.
+        */
+       td->num_unique_pages = (td->o.size * (unsigned long long)td->o.dedupe_working_set_percentage / 100) / td->o.min_bs[DDIR_WRITE];
+       td->dedupe_working_set_states = malloc(sizeof(struct frand_state) * td->num_unique_pages);
+       if (!td->dedupe_working_set_states) {
+               log_err("fio: could not allocate dedupe working set\n");
+               return 1;
+       }
+       frand_copy(&dedupe_working_set_state, &td->buf_state);
+       for (i = 0; i < td->num_unique_pages; i++) {
+               frand_copy(&td->dedupe_working_set_states[i], &dedupe_working_set_state);
+               __get_next_seed(&dedupe_working_set_state);
+       }
+
+       return 0;
+}