Re: Re: [PATCH bpf v2] bpf: Fix deadlock when freeing cgroup storage

[Alexei Starovoitov]

On Tue, Jan 28, 2025 at 10:23 PM Abel Wu <wuyun.abel@xxxxxxxxxxxxx> wrote:
>
> On 1/28/25 7:05 AM, Martin KaFai Lau Wrote:
> > On 1/27/25 2:15 PM, Alexei Starovoitov wrote:
> >> On Sun, Jan 26, 2025 at 1:31 AM Abel Wu <wuyun.abel@xxxxxxxxxxxxx> wrote:
> >>>
> >>> On 1/25/25 4:20 AM, Martin KaFai Lau Wrote:
> >>>>
> >>>> imo, that should be a better option instead of having more unnecessary failures in all other normal use cases which will not be interested in tracing cgroup_storage_ptr().
> >>
> >> Martin,
> >>
> >> task_storage_map_free() is doing this busy inc/dec already,
> >> in that sense doing the same in cgroup_storage_map_free() fits.
> >
> > sgtm. Agree to be consistent with the task_storage_map_free.
> >
> > would be nice if the busy inc/dec usage can be revisited after the rqspinlock work.
>
> Agree, and 1ms interval of deadlock dection seems acceptable
> for most workloads.
>
> >
> > Acked-by: Martin KaFai Lau <martin.lau@xxxxxxxxxx>
>
> Thanks Alexei, Martin.

Applied.