On 11/11/2023 9:39 AM, Yonghong Song wrote:
> Kirill Shutemov reported significant percpu memory consumption increase after
> booting in 288-cpu VM ([1]) due to commit 41a5db8d8161 ("bpf: Add support for
> non-fix-size percpu mem allocation"). The percpu memory consumption is
> increased from 111MB to 969MB. The number is from /proc/meminfo.
>
> I tried to reproduce the issue with my local VM which at most supports upto
> 255 cpus. With 252 cpus, without the above commit, the percpu memory
> consumption immediately after boot is 57MB while with the above commit the
> percpu memory consumption is 231MB.
>
> This is not good since so far percpu memory from bpf memory allocator is not
> widely used yet. Let us change pre-allocation in init stage to on-demand
> allocation when verifier detects there is a need of percpu memory for bpf
> program. With this change, percpu memory consumption after boot can be reduced
> signicantly.
>
> [1] https://lore.kernel.org/lkml/20231109154934.4saimljtqx625l3v@xxxxxxxxxxxxxxxxx/
>
> Fixes: 41a5db8d8161 ("bpf: Add support for non-fix-size percpu mem allocation")
> Reported-and-tested-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
> Signed-off-by: Yonghong Song <yonghong.song@xxxxxxxxx>
Acked-by: Hou Tao <houtao1@xxxxxxxxxx>
