gentoo-overlay/dev-java/icedtea/files/7-cacao-dynmaxheap.patch

# HG changeset patch
# User James Le Cuirot <chewi@gentoo.org>
# Date 1441541110 -3600
#      Sun Sep 06 13:05:10 2015 +0100
# Node ID 80e5553df66e3abb3680f747cbb8e32b394b4211
# Parent  468081e3e037df27b6427aa298dfaaa20f4ba4bf
Dynamically set the maximum heap size on Linux

diff -r 468081e3e037 -r 80e5553df66e src/vm/vm.cpp
--- cacao/cacao/src/vm/vm.cpp	Wed Jun 10 19:52:58 2015 +0200
+++ cacao/cacao/src/vm/vm.cpp	Sun Sep 06 13:05:10 2015 +0100
@@ -32,6 +32,10 @@
 #include <stdint.h>
 #include <inttypes.h>
 
+#if defined(__LINUX__)
+#include <unistd.h>
+#endif
+
 #include "md-abi.hpp"
 
 #include "mm/codememory.hpp"
@@ -690,6 +694,19 @@
 	opt_heapstartsize = HEAP_STARTSIZE;
 	opt_stacksize     = STACK_SIZE;
 
+#if defined(__LINUX__)
+	// Calculate 1/4 of the physical memory.
+	uint64_t qmem = sysconf(_SC_PHYS_PAGES) * sysconf(_SC_PAGESIZE) / 4;
+
+	if (qmem > INT32_MAX) {
+		// More than 2GB will overflow so cap it.
+		opt_heapmaxsize = 2047 * 1024 * 1024;
+	} else if (qmem > HEAP_MAXSIZE) {
+		// Otherwise use this if greater than default (128MB).
+		opt_heapmaxsize = (s4) qmem;
+	}
+#endif
+
 	// First of all, parse the -XX options.
 	options_xx(vm_args);