diff options
| author | Yonghong Song <yonghong.song@linux.dev> | 2023-12-21 19:17:50 -0800 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2024-01-03 21:08:25 -0800 |
| commit | 5b95e638f134e552b5ba2976326c02babe248615 (patch) | |
| tree | ea6a83156f646dd70e550b31b67c441f008da0a6 /kernel | |
| parent | c39aa3b289e9c10d0d246cd919b06809f13b72b8 (diff) | |
bpf: Refill only one percpu element in memalloc
Typically for percpu map element or data structure, once allocated,
most operations are lookup or in-place update. Deletion are really
rare. Currently, for percpu data strcture, 4 elements will be
refilled if the size is <= 256. Let us just do with one element
for percpu data. For example, for size 256 and 128 cpus, the
potential saving will be 3 * 256 * 128 * 128 = 12MB.
Acked-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20231222031750.1289290-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/bpf/memalloc.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/kernel/bpf/memalloc.c b/kernel/bpf/memalloc.c index f71da07eb8a0..a8ee6fb8401c 100644 --- a/kernel/bpf/memalloc.c +++ b/kernel/bpf/memalloc.c @@ -485,11 +485,16 @@ static void init_refill_work(struct bpf_mem_cache *c) static void prefill_mem_cache(struct bpf_mem_cache *c, int cpu) { - /* To avoid consuming memory assume that 1st run of bpf - * prog won't be doing more than 4 map_update_elem from - * irq disabled region + int cnt = 1; + + /* To avoid consuming memory, for non-percpu allocation, assume that + * 1st run of bpf prog won't be doing more than 4 map_update_elem from + * irq disabled region if unit size is less than or equal to 256. + * For all other cases, let us just do one allocation. */ - alloc_bulk(c, c->unit_size <= 256 ? 4 : 1, cpu_to_node(cpu), false); + if (!c->percpu_size && c->unit_size <= 256) + cnt = 4; + alloc_bulk(c, cnt, cpu_to_node(cpu), false); } /* When size != 0 bpf_mem_cache for each cpu. |