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

From: Martin KaFai Lau
Date: Mon Jan 09 2023 - 16:25:42 EST


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@xxxxxxxxx> 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.