* [PATCH bpf-next v1] docs: bpf: map_array: specify BPF_MAP_TYPE_PERCPU_ARRAY value size limit
@ 2025-11-15 6:35 Alex Tran
2025-11-25 22:40 ` patchwork-bot+netdevbpf
0 siblings, 1 reply; 2+ messages in thread
From: Alex Tran @ 2025-11-15 6:35 UTC (permalink / raw)
To: ast, daniel, andrii, corbet
Cc: martin.lau, eddyz87, song, yonghong.song, john.fastabend, kpsingh,
sdf, haoluo, jolsa, bpf, linux-doc, linux-kernel, Alex Tran
Specify value size limit for BPF_MAP_TYPE_PERCPU_ARRAY which
is PCPU_MIN_UNIT_SIZE (32 kb). In percpu allocator (mm: percpu),
any request with a size greater than PCPU_MIN_UNIT_SIZE is rejected.
Signed-off-by: Alex Tran <alex.t.tran@gmail.com>
---
Documentation/bpf/map_array.rst | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/Documentation/bpf/map_array.rst b/Documentation/bpf/map_array.rst
index f2f51a53e8ae..fa56ff75190c 100644
--- a/Documentation/bpf/map_array.rst
+++ b/Documentation/bpf/map_array.rst
@@ -15,8 +15,9 @@ of constant size. The size of the array is defined in ``max_entries`` at
creation time. All array elements are pre-allocated and zero initialized when
created. ``BPF_MAP_TYPE_PERCPU_ARRAY`` uses a different memory region for each
CPU whereas ``BPF_MAP_TYPE_ARRAY`` uses the same memory region. The value
-stored can be of any size, however, all array elements are aligned to 8
-bytes.
+stored can be of any size for ``BPF_MAP_TYPE_ARRAY`` and not more than
+``PCPU_MIN_UNIT_SIZE`` (32 kB) for ``BPF_MAP_TYPE_PERCPU_ARRAY``. All
+array elements are aligned to 8 bytes.
Since kernel 5.5, memory mapping may be enabled for ``BPF_MAP_TYPE_ARRAY`` by
setting the flag ``BPF_F_MMAPABLE``. The map definition is page-aligned and
--
2.51.0
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH bpf-next v1] docs: bpf: map_array: specify BPF_MAP_TYPE_PERCPU_ARRAY value size limit
2025-11-15 6:35 [PATCH bpf-next v1] docs: bpf: map_array: specify BPF_MAP_TYPE_PERCPU_ARRAY value size limit Alex Tran
@ 2025-11-25 22:40 ` patchwork-bot+netdevbpf
0 siblings, 0 replies; 2+ messages in thread
From: patchwork-bot+netdevbpf @ 2025-11-25 22:40 UTC (permalink / raw)
To: Alex Tran
Cc: ast, daniel, andrii, corbet, martin.lau, eddyz87, song,
yonghong.song, john.fastabend, kpsingh, sdf, haoluo, jolsa, bpf,
linux-doc, linux-kernel
Hello:
This patch was applied to bpf/bpf-next.git (master)
by Andrii Nakryiko <andrii@kernel.org>:
On Fri, 14 Nov 2025 22:35:31 -0800 you wrote:
> Specify value size limit for BPF_MAP_TYPE_PERCPU_ARRAY which
> is PCPU_MIN_UNIT_SIZE (32 kb). In percpu allocator (mm: percpu),
> any request with a size greater than PCPU_MIN_UNIT_SIZE is rejected.
>
> Signed-off-by: Alex Tran <alex.t.tran@gmail.com>
> ---
> Documentation/bpf/map_array.rst | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
Here is the summary with links:
- [bpf-next,v1] docs: bpf: map_array: specify BPF_MAP_TYPE_PERCPU_ARRAY value size limit
https://git.kernel.org/bpf/bpf-next/c/44bf4611827b
You are awesome, thank you!
--
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2025-11-25 22:40 ` patchwork-bot+netdevbpf
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