Re: [PATCHv3 perf/core 3/7] tools lib bpf: Add flags to bpf_create_map()

[Wangnan (F)]

On 2016/12/9 10:46, Joe Stringer wrote:

The map_flags argument to bpf_create_map() was previously not exposed.
By exposing it, users can access flags such as whether or not to
preallocate the map.

Signed-off-by: Joe Stringer <j...@ovn.org>

Please mention commit 6c90598174322b8888029e40dd84a4eb01f56afe in
commit message:

Commit 6c905981743 ("bpf: pre-allocate hash map elements") introduces
map_flags to bpf_attr for BPF_MAP_CREATE command. Expose this new
parameter in libbpf.

Acked-by: Wang Nan <wangn...@huawei.com>

---
v3: Split from "tools lib bpf: Sync with samples/bpf/libbpf".
---
  tools/lib/bpf/bpf.c    | 3 ++-
  tools/lib/bpf/bpf.h    | 2 +-
  tools/lib/bpf/libbpf.c | 3 ++-
  3 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index 89e8e8e5b60e..d0afb26c2e0f 100644
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -54,7 +54,7 @@ static int sys_bpf(enum bpf_cmd cmd, union bpf_attr *attr,
  }

int bpf_create_map(enum bpf_map_type map_type, int key_size,

-                  int value_size, int max_entries)
+                  int value_size, int max_entries, __u32 map_flags)
  {
        union bpf_attr attr;

@@ -64,6 +64,7 @@ int bpf_create_map(enum bpf_map_type map_type, int key_size,

        attr.key_size = key_size;
        attr.value_size = value_size;
        attr.max_entries = max_entries;
+       attr.map_flags = map_flags;

return sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr));

  }
diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h
index 61130170a6ad..7fcdce16fd62 100644
--- a/tools/lib/bpf/bpf.h
+++ b/tools/lib/bpf/bpf.h
@@ -24,7 +24,7 @@
  #include <linux/bpf.h>

int bpf_create_map(enum bpf_map_type map_type, int key_size, int value_size,

-                  int max_entries);
+                  int max_entries, __u32 map_flags);

/* Recommend log buffer size */

  #define BPF_LOG_BUF_SIZE 65536
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 2e974593f3e8..84e6b35da4bd 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -854,7 +854,8 @@ bpf_object__create_maps(struct bpf_object *obj)
                *pfd = bpf_create_map(def->type,
                                      def->key_size,
                                      def->value_size,
-                                     def->max_entries);
+                                     def->max_entries,
+                                     0);
                if (*pfd < 0) {
                        size_t j;
                        int err = *pfd;