Commit 8e07bb9e authored by Alexei Starovoitov's avatar Alexei Starovoitov Committed by Daniel Borkmann
Browse files

bpf: Convert bpf_cpumask to bpf_mem_cache_free_rcu. 



Convert bpf_cpumask to bpf_mem_cache_free_rcu.
Note that migrate_disable() in bpf_cpumask_release() is still necessary, since
bpf_cpumask_release() is a dtor. bpf_obj_free_fields() can be converted to do
migrate_disable() there in a follow up.

Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarDavid Vernet <void@manifault.com>
Link: https://lore.kernel.org/bpf/20230706033447.54696-14-alexei.starovoitov@gmail.com
parent 5af6807b

kernel/bpf/cpumask.c

+6 −14
Original line number Diff line number Diff line
@@ -9,7 +9,6 @@ 
/**

 * struct bpf_cpumask - refcounted BPF cpumask wrapper structure

 * @cpumask:	The actual cpumask embedded in the struct.

 * @rcu:	The RCU head used to free the cpumask with RCU safety.

 * @usage:	Object reference counter. When the refcount goes to 0, the

 *		memory is released back to the BPF allocator, which provides

 *		RCU safety.
@@ -25,7 +24,6 @@ 
 */

struct bpf_cpumask {

	cpumask_t cpumask;

	struct rcu_head rcu;

	refcount_t usage;

};
@@ -82,16 +80,6 @@ __bpf_kfunc struct bpf_cpumask *bpf_cpumask_acquire(struct bpf_cpumask *cpumask) 
	return cpumask;

}



static void cpumask_free_cb(struct rcu_head *head)

{

	struct bpf_cpumask *cpumask;



	cpumask = container_of(head, struct bpf_cpumask, rcu);

	migrate_disable();

	bpf_mem_cache_free(&bpf_cpumask_ma, cpumask);

	migrate_enable();

}



/**

 * bpf_cpumask_release() - Release a previously acquired BPF cpumask.

 * @cpumask: The cpumask being released.
@@ -102,8 +90,12 @@ static void cpumask_free_cb(struct rcu_head *head) 
 */

__bpf_kfunc void bpf_cpumask_release(struct bpf_cpumask *cpumask)

{

	if (refcount_dec_and_test(&cpumask->usage))

		call_rcu(&cpumask->rcu, cpumask_free_cb);

	if (!refcount_dec_and_test(&cpumask->usage))

		return;



	migrate_disable();

	bpf_mem_cache_free_rcu(&bpf_cpumask_ma, cpumask);

	migrate_enable();

}



/**