max-cache-size doesn't work with 9.5.0b1

[Mark Andrews]

> On 2008.01.30. 3:28, JINMEI Tatuya / 神明達哉 wrote:
> > Okay, please use the attached patch (applicable to 9.5.0b1, and also
> > to 9.5.0b2 when it's published).  Build it with:
> > % STD_CDEFINES='-DLRU_DEBUG2=2' ./configure --enable-threads
> > (or set STD_CDEFINES using setenv if you use a csh variant)
> >
> > The log messages shouldn't be very noisy, but if you find them too
> > frequent, rebuild it with:
> > % STD_CDEFINES='-DLRU_DEBUG2=1' ./configure --enable-threads
> >
> > Note that, if this is a thread-related bug, it may not always be
> > reproduceable; please try several times if the problem doesn't seem to
> > happen.  (BTW: did it always occur when you first found the problem?)
> >   
> Yes, if bind was built with threads, the memory usage always grew behind 
> max-cache-size very quickly.
> 
> Here is the log:
> http://people.fsn.hu/~bra/freebsd/bind950-memory-20080203/bind950b1
> the memory usage (RSS, reported by top) in megabytes:
> 19:10:37 466
> 19:11:20 522
> 19:11:53 566
> 19:13:06 666
> 19:14:17 766
> 
> max-cache-size was set to 64M.
 
	Please try this patch.

	Mark
 
Index: lib/dns/cache.c
===================================================================
RCS file: /proj/cvs/prod/bind9/lib/dns/cache.c,v
retrieving revision 1.76
diff -u -r1.76 cache.c
--- lib/dns/cache.c	19 Oct 2007 17:15:53 -0000	1.76
+++ lib/dns/cache.c	3 Feb 2008 23:59:46 -0000
@@ -708,8 +708,11 @@
 
         LOCK(&cache->cleaner.lock);
 
-        dns_db_overmem(cache->db, overmem);
-        cache->cleaner.overmem = overmem;
+	if (overmem != cache->cleaner.overmem) {
+		dns_db_overmem(cache->db, overmem);
+		cache->cleaner.overmem = overmem;
+		isc_mem_water(cache->mctx, mark);
+	}
 
         UNLOCK(&cache->cleaner.lock);
 }
Index: lib/isc/mem.c
===================================================================
RCS file: /proj/cvs/prod/bind9/lib/isc/mem.c,v
retrieving revision 1.140
diff -u -r1.140 mem.c
--- lib/isc/mem.c	18 Jan 2008 23:46:58 -0000	1.140
+++ lib/isc/mem.c	3 Feb 2008 23:59:48 -0000
@@ -1086,7 +1086,6 @@
 	ADD_TRACE(ctx, ptr, size, file, line);
 	if (ctx->hi_water != 0U && !ctx->hi_called &&
 	    ctx->inuse > ctx->hi_water) {
-		ctx->hi_called = ISC_TRUE;
 		call_water = ISC_TRUE;
 	}
 	if (ctx->inuse > ctx->maxinuse) {
@@ -1144,8 +1143,6 @@
 	 */
 	if (ctx->hi_called &&
 	    (ctx->inuse < ctx->lo_water || ctx->lo_water == 0U)) {
-		ctx->hi_called = ISC_FALSE;
-
 		if (ctx->water != NULL)
 			call_water = ISC_TRUE;
 	}
@@ -1155,6 +1152,18 @@
 		(ctx->water)(ctx->water_arg, ISC_MEM_LOWATER);
 }
 
+void
+isc_mem_water(isc_mem_t *ctx, int flag) {
+	REQUIRE(VALID_CONTEXT(ctx));
+
+	MCTXLOCK(ctx, &ctx->lock);
+	if (flag == ISC_MEM_LOWATER)
+		ctx->hi_called = ISC_FALSE;
+	else if (flag == ISC_MEM_HIWATER)
+		ctx->hi_called = ISC_TRUE;
+	MCTXUNLOCK(ctx, &ctx->lock);
+}
+
 #if ISC_MEM_TRACKLINES
 static void
 print_active(isc_mem_t *mctx, FILE *out) {
-- 
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: Mark_Andrews at isc.org