Messages in this thread | | | From | Hao Luo <> | Date | Tue, 29 Nov 2022 21:02:11 -0800 | Subject | Re: [net-next] bpf: avoid hashtab deadlock with try_lock |
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On Tue, Nov 29, 2022 at 8:13 PM Hou Tao <houtao@huaweicloud.com> wrote: > > On 11/30/2022 10:47 AM, Tonghao Zhang wrote: <...> > > if (in_nmi()) { > > if (!raw_spin_trylock_irqsave(&b->raw_lock, flags)) > > return -EBUSY; > > The only purpose of trylock here is to make lockdep happy and it may lead to > unnecessary -EBUSY error for htab operations in NMI context. I still prefer add > a virtual lock-class for map_locked to fix the lockdep warning. So could you use > separated patches to fix the potential dead-lock and the lockdep warning ? It > will be better you can also add a bpf selftests for deadlock problem as said before. >
Agree with Tao here. Tonghao, could you send another version which:
- separates the fix to deadlock and the fix to lockdep warning - includes a bpf selftest to verify the fix to deadlock - with bpf-specific tag: [PATCH bpf-next]
There are multiple ideas on the fly in this thread, it's easy to lose track of what has been proposed and what change you intend to make.
Thanks, Hao
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