Changeset: ed2de4b786d9 for MonetDB
URL: http://dev.monetdb.org/hg/MonetDB?cmd=changeset;node=ed2de4b786d9
Modified Files:
gdk/gdk_bbp.c
Branch: Oct2014
Log Message:
Limit the time it takes to find a long free list.
See the changed comment in the code.
diffs (57 lines):
diff --git a/gdk/gdk_bbp.c b/gdk/gdk_bbp.c
--- a/gdk/gdk_bbp.c
+++ b/gdk/gdk_bbp.c
@@ -1703,24 +1703,28 @@ BBPcurstamp(void)
}
/* There are BBP_THREADMASK+1 (64) free lists, and ours (idx) is
- * empty. Here we find the longest free list, and if it is long
- * enough (> 20 entries) we take one entry from that list. If the
- * longest list isn't long enough, we create a new entry by either
- * just increasing BBPsize (up to BBPlimit) or extending the BBP
- * (which increases BBPlimit). */
+ * empty. Here we find a longish free list (at least 20 entries), and
+ * if we can find one, we take one entry from that list. If no long
+ * enough list can be found, we create a new entry by either just
+ * increasing BBPsize (up to BBPlimit) or extending the BBP (which
+ * increases BBPlimit). Every time this function is called we start
+ * searching in a following free list (variable "last"). */
static void
maybeextend(int idx)
{
int t, m;
int n, l;
bat i;
+ static int last = 0;
l = 0; /* length of longest list */
m = 0; /* index of longest list */
- /* find longest free list */
- for (t = 0; t <= BBP_THREADMASK; t++) {
+ /* find a longish free list */
+ for (t = 0; t <= BBP_THREADMASK && l <= 20; t++) {
n = 0;
- for (i = BBP_free(t); i != 0; i = BBP_next(i))
+ for (i = BBP_free((t + last) & BBP_THREADMASK);
+ i != 0 && n <= 20;
+ i = BBP_next(i))
n++;
if (n > l) {
m = t;
@@ -1728,7 +1732,7 @@ maybeextend(int idx)
}
}
if (l > 20) {
- /* longest list is long enough, get an entry from there */
+ /* list is long enough, get an entry from there */
i = BBP_free(m);
BBP_free(m) = BBP_next(i);
BBP_next(i) = 0;
@@ -1741,6 +1745,7 @@ maybeextend(int idx)
BBP_free(idx) = (bat) ATOMIC_GET(BBPsize, BBPsizeLock,
"BBPinsert") - 1;
}
}
+ last = (last + 1) & BBP_THREADMASK;
}
bat
_______________________________________________
checkin-list mailing list
checkin-list@monetdb.org
https://www.monetdb.org/mailman/listinfo/checkin-list
