netdev - Re: [PATCH bpf-next v5 00/16] Remove task and cgroup local storage percpu counters

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Message-ID: <CAADnVQKxcbWB03cu7j0RC6-iR1gT=m6n8ZgqDpoQXW0MB+eqUA@mail.gmail.com>
Date: Sun, 1 Feb 2026 15:29:26 -0800
From: Alexei Starovoitov <alexei.starovoitov@...il.com>
To: Amery Hung <ameryhung@...il.com>
Cc: bpf <bpf@...r.kernel.org>, Network Development <netdev@...r.kernel.org>, 
	Andrii Nakryiko <andrii@...nel.org>, Daniel Borkmann <daniel@...earbox.net>, 
	Kumar Kartikeya Dwivedi <memxor@...il.com>, Martin KaFai Lau <martin.lau@...nel.org>, KP Singh <kpsingh@...nel.org>, 
	Yonghong Song <yonghong.song@...ux.dev>, Song Liu <song@...nel.org>, Hao Luo <haoluo@...gle.com>, 
	Kernel Team <kernel-team@...a.com>
Subject: Re: [PATCH bpf-next v5 00/16] Remove task and cgroup local storage
 percpu counters

On Sun, Feb 1, 2026 at 9:50 AM Amery Hung <ameryhung@...il.com> wrote:
>
> To remove the percpu counter without introducing deadlock,
> bpf_local_storage is refactored by changing the locks from raw_spin_lock
> to rqspinlock, which prevents deadlock with deadlock detection and a
> timeout mechanism.
>
> The refactor basically repalces the locks with rqspinlock and propagates
> errors returned by the locking function to BPF helpers or syscalls.
> bpf_selem_unlink_nofail() is introduced to handle rqspinlock errors
> in two lock acquiring functions that cannot fail,
> bpf_local_storage_destroy() and bpf_local_storage_map_free()
> (i.e., local storage is being freed by the subsystem or the map is
> being freed). The high level idea is to refcounting selem when any locks
> cannot be acquired. Additional care is needed to make sure special fields
> are freed and owner memory are uncharged safely and correctly.

for the set:

Acked-by: Alexei Starovoitov <ast@...nel.org>

Martin,
pls do another pass and apply if it looks good.