svn commit: r1575433 - /subversion/trunk/subversion/libsvn_subr/cache-membuffer.c

[st...@apache.org]

Author: stefan2
Date: Fri Mar  7 22:25:15 2014
New Revision: 1575433

URL: http://svn.apache.org/r1575433
Log:
* subversion/libsvn_subr/cache-membuffer.c
  (get_group_index): Tune the key->bucket mapping function to distribute
                     cached objects more evenly across the segments.

Modified:
    subversion/trunk/subversion/libsvn_subr/cache-membuffer.c

Modified: subversion/trunk/subversion/libsvn_subr/cache-membuffer.c
URL: http://svn.apache.org/viewvc/subversion/trunk/subversion/libsvn_subr/cache-membuffer.c?rev=1575433&r1=1575432&r2=1575433&view=diff
==============================================================================
--- subversion/trunk/subversion/libsvn_subr/cache-membuffer.c (original)
+++ subversion/trunk/subversion/libsvn_subr/cache-membuffer.c Fri Mar  7 22:25:15 2014
@@ -1093,10 +1093,10 @@ get_group_index(svn_membuffer_t **cache,
 
   /* select the cache segment to use. they have all the same group_count.
    * Since key may not be well-distributed, pre-fold it to a smaller but
-   * "denser" ranger.  The divisors are primes larger than the largest
+   * "denser" ranger.  The modulus is a prime larger than the largest
    * counts. */
-  *cache = &segment0[(key[1] % APR_UINT64_C(2809637))
-         & (segment0->segment_count - 1)];
+  *cache = &segment0[(key[1] % APR_UINT64_C(2809637) + (key[0] / 37))
+                     & (segment0->segment_count - 1)];
   return (key[0] % APR_UINT64_C(5030895599)) % segment0->group_count;
 }