On Thu, Feb 16, 2023 at 10:48:21AM +0800, 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> > --- > v2: fix typo (forget to regenerate the patch after testing) > v1: https://lore.kernel.org/bpf/7736864d-af8d-4f74-086b-0ec125aae2a6@xxxxxxxxxx/T/#t Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx> jirka > > 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..2b3fbbfebdc5 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, 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, > -- > 2.29.2 >
