From b21227bb3b7a71c137d162fa5acf98ac6db69627 Mon Sep 17 00:00:00 2001
From: Steffen Vogel <post@steffenvogel.de>
Date: Fri, 23 Nov 2018 19:42:18 +0200
Subject: [PATCH] memory: speedup hugepage memory allocations

---
 include/villas/memory_type.h |  2 +
 lib/memory.c                 |  9 +++-
 lib/memory/hugepage.c        | 79 +++++++++++++++++++++++-------------
 3 files changed, 60 insertions(+), 30 deletions(-)

diff --git a/include/villas/memory_type.h b/include/villas/memory_type.h
index d697fe978..2196a7158 100644
--- a/include/villas/memory_type.h
+++ b/include/villas/memory_type.h
@@ -62,6 +62,8 @@ extern struct memory_type memory_hugepage;
 struct memory_type * memory_ib(struct node *n, struct memory_type *parent);
 struct memory_type * memory_managed(void *ptr, size_t len);
 
+int memory_hugepage_init();
+
 struct memory_type * memory_type_lookup(enum memory_type_flags flags);
 
 #ifdef __cplusplus
diff --git a/lib/memory.c b/lib/memory.c
index 8d92552d5..c7a2b265b 100644
--- a/lib/memory.c
+++ b/lib/memory.c
@@ -51,8 +51,15 @@ static void destroy_allocations()
 
 int memory_init(int hugepages)
 {
+	int ret;
+
 	info("Initialize memory sub-system: #hugepages=%d", hugepages);
 
+	/* Initialize hugepage allocator */
+	ret = memory_hugepage_init();
+	if (ret)
+		return ret;
+
 #if defined(__linux__) && defined(__x86_64__)
 	int pagecnt, pagesz, ret;
 	struct rlimit l;
@@ -101,7 +108,7 @@ int memory_init(int hugepages)
 		if (ret)
 			return ret;
 
-		debug(LOG_MEM | 2, "Increased ressource limit of locked memory to %d bytes", pagesz * pagecnt);
+		debug(LOG_MEM | 2, "Increased ressource limit of locked memory to %d bytes", lock);
 	}
 #endif
 	return 0;
diff --git a/lib/memory/hugepage.c b/lib/memory/hugepage.c
index 714a4162f..8366f60f4 100644
--- a/lib/memory/hugepage.c
+++ b/lib/memory/hugepage.c
@@ -21,6 +21,7 @@
  *********************************************************************************/
 
 #include <stdlib.h>
+#include <stdbool.h>
 #include <unistd.h>
 #include <errno.h>
 #include <strings.h>
@@ -41,49 +42,69 @@
 #include <villas/utils.h>
 #include <villas/kernel/kernel.h>
 
+static size_t pgsz = -1;
+static size_t hugepgsz = -1;
+static bool use_huge = true;
+
+int memory_hugepage_init()
+{
+	pgsz = kernel_get_page_size();
+	if (pgsz < 0)
+		return -1;
+
+	hugepgsz = kernel_get_hugepage_size();
+	if (hugepgsz < 0)
+		return -1;
+
+	return 0;
+}
+
 /** Allocate memory backed by hugepages with malloc() like interface */
 static struct memory_allocation * memory_hugepage_alloc(struct memory_type *m, size_t len, size_t alignment)
 {
-	int prot = PROT_READ | PROT_WRITE;
-	int flags = MAP_PRIVATE | MAP_ANONYMOUS;
-	int ret, fd = -1;
-
-	size_t pgsz = kernel_get_page_size();
-	size_t hugepgsz = kernel_get_hugepage_size();
-
-#ifdef __MACH__
-	fd = VM_FLAGS_SUPERPAGE_SIZE_2MB;
-#elif defined(__linux__)
-	flags |= MAP_HUGETLB;
-#endif
+	int ret, flags, fd;
+	size_t sz;
 
 	struct memory_allocation *ma = alloc(sizeof(struct memory_allocation));
 	if (!ma)
 		return NULL;
 
-	/** We must make sure that len is a multiple of the hugepage size
+retry:	if (use_huge) {
+#ifdef __linux__
+		flags = MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB;
+#else
+		flags = MAP_PRIVATE | MAP_ANONYMOUS;
+#endif
+
+#ifdef __MACH__
+		fd = VM_FLAGS_SUPERPAGE_SIZE_2MB;
+#else
+		fd = -1;
+#endif
+		sz = hugepgsz;
+	}
+	else {
+		flags = MAP_PRIVATE | MAP_ANONYMOUS;
+		fd = -1;
+
+		sz = pgsz;
+	}
+
+	/** We must make sure that len is a multiple of the (huge)page size
 	 *
 	 * See: https://lkml.org/lkml/2014/10/22/925
 	 */
-	ma->length = ALIGN(len, hugepgsz);
-	ma->alignment = ALIGN(alignment, hugepgsz);
+	ma->length = ALIGN(len, sz);
+	ma->alignment = ALIGN(alignment, sz);
 	ma->type = m;
 
-	ma->address = mmap(NULL, ma->length, prot, flags, fd, 0);
+	ma->address = mmap(NULL, ma->length, PROT_READ | PROT_WRITE, flags, fd, 0);
 	if (ma->address == MAP_FAILED) {
-		warn("memory_hugepage_alloc: %s. Mapped as normal pages instead!", strerror(errno));
-		//warn("  aligned=%#zx, length=%#zx", ma->alignment, ma->length);
-
-#ifdef __MACH__
-		fd = -1;
-#elif defined(__linux__)
-		flags &= ~MAP_HUGETLB;
-#endif
-
-		ma->length = ALIGN(len, pgsz);
-		ma->alignment = ALIGN(alignment, pgsz);
-		ma->address = mmap(NULL, ma->length, prot, flags, fd, 0);
-		if (ma->address == MAP_FAILED) {
+		if (use_huge) {
+			use_huge = false;
+			goto retry;
+		}
+		else {
 			free(ma);
 			return NULL;
 		}