On Mon, Apr 11, 2022 at 4:41 PM Song Liu <[email protected]> wrote:
>
> module_alloc_huge for bpf_prog_pack so that BPF programs sit on PMD_SIZE
> pages. This benefits system performance by reducing iTLB miss rate.
>
> Signed-off-by: Song Liu <[email protected]>
I am really sorry for spamming the list twice. The first set
experienced long lag,
so I thought it didn't get through.
I also updated the commit log of 3/3, and this one is the latest version.
Thanks,
Song
> ---
> kernel/bpf/core.c | 9 +++++----
> 1 file changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
> index 13e9dbeeedf3..fd45bdd80a75 100644
> --- a/kernel/bpf/core.c
> +++ b/kernel/bpf/core.c
> @@ -857,7 +857,7 @@ static size_t select_bpf_prog_pack_size(void)
> void *ptr;
>
> size = BPF_HPAGE_SIZE * num_online_nodes();
> - ptr = module_alloc(size);
> + ptr = module_alloc_huge(size);
>
> /* Test whether we can get huge pages. If not just use PAGE_SIZE
> * packs.
> @@ -881,7 +881,7 @@ static struct bpf_prog_pack *alloc_new_pack(void)
> GFP_KERNEL);
> if (!pack)
> return NULL;
> - pack->ptr = module_alloc(bpf_prog_pack_size);
> + pack->ptr = module_alloc_huge(bpf_prog_pack_size);
> if (!pack->ptr) {
> kfree(pack);
> return NULL;
> @@ -889,7 +889,6 @@ static struct bpf_prog_pack *alloc_new_pack(void)
> bitmap_zero(pack->bitmap, bpf_prog_pack_size / BPF_PROG_CHUNK_SIZE);
> list_add_tail(&pack->list, &pack_list);
>
> - set_vm_flush_reset_perms(pack->ptr);
> set_memory_ro((unsigned long)pack->ptr, bpf_prog_pack_size / PAGE_SIZE);
> set_memory_x((unsigned long)pack->ptr, bpf_prog_pack_size / PAGE_SIZE);
> return pack;
> @@ -970,7 +969,9 @@ static void bpf_prog_pack_free(struct bpf_binary_header *hdr)
> if (bitmap_find_next_zero_area(pack->bitmap, bpf_prog_chunk_count(), 0,
> bpf_prog_chunk_count(), 0) == 0) {
> list_del(&pack->list);
> - module_memfree(pack->ptr);
> + set_memory_nx((unsigned long)pack->ptr, bpf_prog_pack_size / PAGE_SIZE);
> + set_memory_rw((unsigned long)pack->ptr, bpf_prog_pack_size / PAGE_SIZE);
> + vfree(pack->ptr);
> kfree(pack);
> }
> out:
> --
> 2.30.2
>
>