numa support: allow disabling numa support

[lttng-ust.git] / libringbuffer / shm.c

diff --git a/libringbuffer/shm.c b/libringbuffer/shm.c
index c4c651e4b925543e373e9b016398636be4c03293..0153578c93a2cfddf3bdd69ae57324b516086651 100644 (file)
--- 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>
@@ -32,6 +33,9 @@
 #include <dirent.h>
 #include <lttng/align.h>
 #include <limits.h>
+#ifdef HAVE_LIBNUMA
+#include <numa.h>
+#endif
 #include <helper.h>
 #include <ust-fd.h>
 
@@ -134,6 +138,15 @@ 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;
 
@@ -153,6 +166,7 @@ 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:
@@ -233,18 +247,37 @@ alloc_error:
 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, node;
+
+       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
+       numa_set_preferred(oldnode);
+#endif /* HAVE_LIBNUMA */
+       return shm_object;
 }
 
 struct shm_object *shm_object_table_append_shm(struct shm_object_table *table,