bpf: Only allocate one bpf_mem_cache for bpf_cpumask_ma

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@huawei.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230216024821.2202916-1-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Hou Tao 2023-02-16 10:48:21 +08:00 committed by Alexei Starovoitov
parent dbd8d22863
commit 5d5de3a431
2 changed files with 10 additions and 3 deletions

View File

@ -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);

View File

@ -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, sizeof(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,