Sorry, please disregard this patch. I forgot to fix the typo in it. Will resend.
On 2/16/2023 10:41 AM, Hou Tao wrote:
> From: Hou Tao <houtao1@xxxxxxxxxx>
>
> The size of bpf_cpumask is fixed, so there is no need to allocate many
> bpf_mem_caches for bpf_cpumask_ma, just one bpf_mem_cache is enough.
> Also add comments for bpf_mem_alloc_init() in bpf_mem_alloc.h to prevent
> future miuse.
>
> Signed-off-by: Hou Tao <houtao1@xxxxxxxxxx>
> ---
> include/linux/bpf_mem_alloc.h | 7 +++++++
> kernel/bpf/cpumask.c | 6 +++---
> 2 files changed, 10 insertions(+), 3 deletions(-)
>
> diff --git a/include/linux/bpf_mem_alloc.h b/include/linux/bpf_mem_alloc.h
> index 3e164b8efaa9..a7104af61ab4 100644
> --- a/include/linux/bpf_mem_alloc.h
> +++ b/include/linux/bpf_mem_alloc.h
> @@ -14,6 +14,13 @@ struct bpf_mem_alloc {
> struct work_struct work;
> };
>
> +/* 'size != 0' is for bpf_mem_alloc which manages fixed-size objects.
> + * Alloc and free are done with bpf_mem_cache_{alloc,free}().
> + *
> + * 'size = 0' is for bpf_mem_alloc which manages many fixed-size objects.
> + * Alloc and free are done with bpf_mem_{alloc,free}() and the size of
> + * the returned object is given by the size argument of bpf_mem_alloc().
> + */
> int bpf_mem_alloc_init(struct bpf_mem_alloc *ma, int size, bool percpu);
> void bpf_mem_alloc_destroy(struct bpf_mem_alloc *ma);
>
> diff --git a/kernel/bpf/cpumask.c b/kernel/bpf/cpumask.c
> index 52b981512a35..711434b556fb 100644
> --- a/kernel/bpf/cpumask.c
> +++ b/kernel/bpf/cpumask.c
> @@ -55,7 +55,7 @@ __bpf_kfunc struct bpf_cpumask *bpf_cpumask_create(void)
> /* cpumask must be the first element so struct bpf_cpumask be cast to struct cpumask. */
> BUILD_BUG_ON(offsetof(struct bpf_cpumask, cpumask) != 0);
>
> - cpumask = bpf_mem_alloc(&bpf_cpumask_ma, sizeof(*cpumask));
> + cpumask = bpf_mem_cache_alloc(&bpf_cpumask_ma);
> if (!cpumask)
> return NULL;
>
> @@ -123,7 +123,7 @@ __bpf_kfunc void bpf_cpumask_release(struct bpf_cpumask *cpumask)
>
> if (refcount_dec_and_test(&cpumask->usage)) {
> migrate_disable();
> - bpf_mem_free(&bpf_cpumask_ma, cpumask);
> + bpf_mem_cache_free(&bpf_cpumask_ma, cpumask);
> migrate_enable();
> }
> }
> @@ -468,7 +468,7 @@ static int __init cpumask_kfunc_init(void)
> },
> };
>
> - ret = bpf_mem_alloc_init(&bpf_cpumask_ma, 0, false);
> + ret = bpf_mem_alloc_init(&bpf_cpumask_ma, sieof(struct bpf_cpumask), false);
> ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, &cpumask_kfunc_set);
> ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_STRUCT_OPS, &cpumask_kfunc_set);
> return ret ?: register_btf_id_dtor_kfuncs(cpumask_dtors,
