Optimize pattern verify

[fio.git] / verify.c

diff --git a/verify.c b/verify.c
index 9ee3bc42ca215961b03951445fdb64070b3f35aa..eb8eddc78906f4b0dcaa13a9899495e5a8670dca 100644 (file)
--- a/verify.c
+++ b/verify.c
@@ -322,14 +322,27 @@ static int verify_io_u_pattern(struct verify_header *hdr, struct vcont *vc)
        struct io_u *io_u = vc->io_u;
        char *buf, *pattern;
        unsigned int header_size = __hdr_size(td->o.verify);
-       unsigned int len, mod, i;
+       unsigned int len, mod, i, size, pattern_size;
 
        pattern = td->o.verify_pattern;
+       pattern_size = td->o.verify_pattern_bytes;
+       if (pattern_size <= 1)
+               pattern_size = MAX_PATTERN_SIZE;
        buf = (void *) hdr + header_size;
        len = get_hdr_inc(td, io_u) - header_size;
-       mod = header_size % td->o.verify_pattern_bytes;
+       mod = header_size % pattern_size;
+
+       for (i = 0; i < len; i += size) {
+               size = pattern_size - mod;
+               if (size > (len - i))
+                       size = len - i;
+               if (memcmp(buf + i, pattern + mod, size))
+                       // Let the slow compare find the first mismatch byte.
+                       break;
+               mod = 0;
+       }
 
-       for (i = 0; i < len; i++) {
+       for (; i < len; i++) {
                if (buf[i] != pattern[mod]) {
                        unsigned int bits;