Re: [PATCH] perf lock contention: Do not use BPF task local storage

Martin KaFai Lau
2023-01-09T21:25:42Z

On 1/9/23 12:56 PM, Namhyung Kim wrote:
> Hello,
>
> On Mon, Nov 21, 2022 at 9:33 AM Martin KaFai Lau <martin.lau@linux.dev> wrote:
>>
>> On 11/18/22 11:01 AM, Namhyung Kim wrote:
>>> We could fix the task local storage to use the safe BPF allocator,
>>> but it takes time so let's change this until it happens actually.
>>
>> I also got another report on the kfree_rcu path. I am also looking into this
>> direction on using the BPF allocator.
>
> Any progress on this? Are there any concerns about the change?

Yep, I am working on it. It is not a direct replacement from kzalloc to
bpf_mem_cache_alloc. eg. Some changes in the bpf mem allocator is needed to
ensure the free list cannot be reused before the rcu grace period. There is a
similar RFC patchset going into this direction that I am trying with.