bpf: follow idr code convention
Generally we do a preload before doing idr allocation. This also help
improve the allocation success rate in memory pressure.
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index dd172ee..77d45bd 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -203,11 +203,13 @@ static int bpf_map_alloc_id(struct bpf_map *map)
{
int id;
+ idr_preload(GFP_KERNEL);
spin_lock_bh(&map_idr_lock);
id = idr_alloc_cyclic(&map_idr, map, 1, INT_MAX, GFP_ATOMIC);
if (id > 0)
map->id = id;
spin_unlock_bh(&map_idr_lock);
+ idr_preload_end();
if (WARN_ON_ONCE(!id))
return -ENOSPC;
@@ -940,11 +942,13 @@ static int bpf_prog_alloc_id(struct bpf_prog *prog)
{
int id;
+ idr_preload(GFP_KERNEL);
spin_lock_bh(&prog_idr_lock);
id = idr_alloc_cyclic(&prog_idr, prog, 1, INT_MAX, GFP_ATOMIC);
if (id > 0)
prog->aux->id = id;
spin_unlock_bh(&prog_idr_lock);
+ idr_preload_end();
/* id is in [1, INT_MAX) */
if (WARN_ON_ONCE(!id))