increase number of reserved huge pages automatically if required

config.h

@@ -24,6 +24,10 @@
 #define DEFAULT_VALUES		64
 #define DEFAULT_QUEUELEN	1024
 
+/** Number of hugepages which are requested from the the kernel.
+ * @see https://www.kernel.org/doc/Documentation/vm/hugetlbpage.txt */
+#define DEFAULT_NR_HUGEPAGES	25
+
 /** Width of log output in characters */
 #define LOG_WIDTH		132
 

include/villas/kernel/kernel.h

@@ -12,6 +12,8 @@
 
 #include <stdint.h>
 
+#include "config.h"
+
 //#include <sys/capability.h>
 
 /** Check if current process has capability \p cap.
@@ -19,7 +21,13 @@
  * @retval 0 If capabilty is present.
  * @retval <0 If capability is not present.
  */
-//int kernel_check_cap(cap_value_t cap):
+//int kernel_check_cap(cap_value_t cap);
+
+/** Get number of reserved hugepages. */
+int kernel_get_nr_hugepages();
+
+/** Set number of reserved hugepages. */
+int kernel_set_nr_hugepages(int nr);
 
 /** Checks for realtime (PREEMPT_RT) patched kernel.
  *

include/villas/memory.h

@@ -44,6 +44,9 @@ struct memzone {
 	size_t len; 
 };
 
+/** Initilialize memory subsystem */
+int memory_init();
+
 /** Allocate \p len bytes memory of type \p m.
  *
  * @retval NULL If allocation failed.

lib/kernel/kernel.c

@@ -152,6 +152,38 @@ int kernel_get_cacheline_size()
 	return sysconf(_SC_LEVEL1_ICACHE_LINESIZE);
 }
 
+int kernel_get_nr_hugepages()
+{
+	FILE *f;
+	int nr, ret;
+	
+	f = fopen(PROCFS_PATH "/sys/vm/nr_hugepages", "r");
+	if (!f)
+		serror("Failed to open %s", PROCFS_PATH "/sys/vm/nr_hugepages");
+	
+	ret = fscanf(f, "%d", &nr);
+	if (ret != 1)
+		nr = -1;
+		
+	fclose(f);
+	
+	return nr;
+}
+
+int kernel_set_nr_hugepages(int nr)
+{
+	FILE *f;
+
+	f = fopen(PROCFS_PATH "/sys/vm/nr_hugepages", "w");
+	if (!f)
+		serror("Failed to open %s", PROCFS_PATH "/sys/vm/nr_hugepages");
+	
+	fprintf(f, "%d\n", nr);
+	fclose(f);
+	
+	return 0;
+}
+
 #if 0
 int kernel_check_cap(cap_value_t cap)
 {

lib/memory.c

@@ -12,11 +12,26 @@
 /* Required to allocate hugepages on Apple OS X */
 #ifdef __MACH__
   #include <mach/vm_statistics.h>
+#elif defined(__linux__)
+  #include "kernel/kernel.h"
 #endif
 
 #include "log.h"
 #include "memory.h"
 
+int memory_init()
+{
+#ifdef __linux__
+	int nr = kernel_get_nr_hugepages();
+	
+	debug(DBG_MEM | 2, "System has %d reserved hugepages", nr);
+	
+	if (nr < DEFAULT_NR_HUGEPAGES)
+		kernel_set_nr_hugepages(DEFAULT_NR_HUGEPAGES);
+#endif
+	return 0;
+}
+
 void * memory_alloc(const struct memtype *m, size_t len)
 {
 	debug(DBG_MEM | 2, "Allocating %#zx bytes of %s memory", len, m->name);

src/node.c

@@ -17,6 +17,7 @@
 #include <villas/utils.h>
 #include <villas/cfg.h>
 #include <villas/path.h>
+#include <villas/memory.h>
 #include <villas/node.h>
 #include <villas/kernel/kernel.h>
 #include <villas/kernel/rt.h>
@@ -124,6 +125,9 @@ int main(int argc, char *argv[])
 
 	info("Initialize real-time system");
 	rt_init(settings.affinity, settings.priority);
+	
+	info("Initialize memory system");
+	memory_init();
 
 	info("Initialize signals");
 	signals_init();

src/pipe.c

@@ -225,6 +225,9 @@ int main(int argc, char *argv[])
 	info("Initialize real-time system");
 	rt_init(settings.affinity, settings.priority);
 	
+	info("Initialize memory system");
+	memory_init();
+	
 	/* Initialize node */
 	node = list_lookup(&nodes, argv[2]);
 	if (!node)

src/test.c

@@ -87,6 +87,9 @@ int main(int argc, char *argv[])
 	log_init();
 	cfg_parse(argv[1], &config, &settings, &nodes, NULL);
 
+	info("Initialize memory system");
+	memory_init();
+
 	node = list_lookup(&nodes, argv[3]);
 	if (!node)
 		error("There's no node with the name '%s'", argv[3]);

tests/Makefile.inc

@@ -8,7 +8,6 @@ TEST_LDLIBS = $(LDLIBS) -lcriterion -lvillas -pthread
 tests: $(BUILDDIR)/testsuite
 
 run-tests: tests
-	echo 25 > /proc/sys/vm/nr_hugepages
 	$(BUILDDIR)/testsuite
 
 # Compile