X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=libringbuffer%2Fshm.c;h=44a830af20446142f8e21177b5187e8dfd6d4af0;hb=fb31eb73d8a4a6d9784ed5c335b7fa3b9684108c;hp=8ac321e3931906888f79dd9e2419a7dbca8225de;hpb=429dadf0e28fe24be158ddb76d09f5f2308b6467;p=lttng-ust.git

diff --git a/libringbuffer/shm.c b/libringbuffer/shm.c
index 8ac321e3..44a830af 100644
--- a/libringbuffer/shm.c
+++ b/libringbuffer/shm.c
@@ -19,6 +19,7 @@
  */
 
 #define _LGPL_SOURCE
+#include <config.h>
 #include "shm.h"
 #include <unistd.h>
 #include <fcntl.h>
@@ -32,16 +33,20 @@
 #include <dirent.h>
 #include <lttng/align.h>
 #include <limits.h>
+#include <stdbool.h>
+#include <stdint.h>
+#ifdef HAVE_LIBNUMA
+#include <numa.h>
+#include <numaif.h>
+#endif
 #include <helper.h>
 #include <ust-fd.h>
+#include "mmap.h"
 
 /*
  * Ensure we have the required amount of space available by writing 0
  * into the entire buffer. Not doing so can trigger SIGBUS when going
  * beyond the available shm space.
- *
- * Also ensure the file metadata is synced with the storage by using
- * fsync(2).
  */
 static
 int zero_file(int fd, size_t len)
@@ -70,11 +75,6 @@ int zero_file(int fd, size_t len)
 		}
 		written += retlen;
 	}
-	ret = fsync(fd);
-	if (ret) {
-		ret = (int) -errno;
-		goto error;
-	}
 	ret = 0;
 error:
 	free(zeropage);
@@ -142,12 +142,21 @@ struct shm_object *_shm_object_table_alloc_shm(struct shm_object_table *table,
 		PERROR("ftruncate");
 		goto error_ftruncate;
 	}
+	/*
+	 * Also ensure the file metadata is synced with the storage by using
+	 * fsync(2).
+	 */
+	ret = fsync(shmfd);
+	if (ret) {
+		PERROR("fsync");
+		goto error_fsync;
+	}
 	obj->shm_fd_ownership = 0;
 	obj->shm_fd = shmfd;
 
 	/* memory_map: mmap */
 	memory_map = mmap(NULL, memory_map_size, PROT_READ | PROT_WRITE,
-			  MAP_SHARED, shmfd, 0);
+			  MAP_SHARED | LTTNG_MAP_POPULATE, shmfd, 0);
 	if (memory_map == MAP_FAILED) {
 		PERROR("mmap");
 		goto error_mmap;
@@ -161,6 +170,7 @@ struct shm_object *_shm_object_table_alloc_shm(struct shm_object_table *table,
 	return obj;
 
 error_mmap:
+error_fsync:
 error_ftruncate:
 error_zero_file:
 error_fcntl:
@@ -238,21 +248,63 @@ alloc_error:
 	return NULL;
 }
 
+/*
+ * libnuma prints errors on the console even for numa_available().
+ * Work-around this limitation by using get_mempolicy() directly to
+ * check whether the kernel supports mempolicy.
+ */
+#ifdef HAVE_LIBNUMA
+static bool lttng_is_numa_available(void)
+{
+	int ret;
+
+	ret = get_mempolicy(NULL, NULL, 0, NULL, 0);
+	if (ret && errno == ENOSYS) {
+		return false;
+	}
+	return numa_available() > 0;
+}
+#endif
+
 struct shm_object *shm_object_table_alloc(struct shm_object_table *table,
 			size_t memory_map_size,
 			enum shm_object_type type,
-			int stream_fd)
+			int stream_fd,
+			int cpu)
 {
+	struct shm_object *shm_object;
+#ifdef HAVE_LIBNUMA
+	int oldnode = 0, node;
+	bool numa_avail;
+
+	numa_avail = lttng_is_numa_available();
+	if (numa_avail) {
+		oldnode = numa_preferred();
+		if (cpu >= 0) {
+			node = numa_node_of_cpu(cpu);
+			if (node >= 0)
+				numa_set_preferred(node);
+		}
+		if (cpu < 0 || node < 0)
+			numa_set_localalloc();
+	}
+#endif /* HAVE_LIBNUMA */
 	switch (type) {
 	case SHM_OBJECT_SHM:
-		return _shm_object_table_alloc_shm(table, memory_map_size,
+		shm_object = _shm_object_table_alloc_shm(table, memory_map_size,
 				stream_fd);
+		break;
 	case SHM_OBJECT_MEM:
-		return _shm_object_table_alloc_mem(table, memory_map_size);
+		shm_object = _shm_object_table_alloc_mem(table, memory_map_size);
+		break;
 	default:
 		assert(0);
 	}
-	return NULL;
+#ifdef HAVE_LIBNUMA
+	if (numa_avail)
+		numa_set_preferred(oldnode);
+#endif /* HAVE_LIBNUMA */
+	return shm_object;
 }
 
 struct shm_object *shm_object_table_append_shm(struct shm_object_table *table,
@@ -291,7 +343,7 @@ struct shm_object *shm_object_table_append_shm(struct shm_object_table *table,
 
 	/* memory_map: mmap */
 	memory_map = mmap(NULL, memory_map_size, PROT_READ | PROT_WRITE,
-			  MAP_SHARED, shm_fd, 0);
+			  MAP_SHARED | LTTNG_MAP_POPULATE, shm_fd, 0);
 	if (memory_map == MAP_FAILED) {
 		PERROR("mmap");
 		goto error_mmap;