Re: [PATCH] bpf: convert hashtab lock to raw lock

From	"Shi, Yang" <yang.shi@linaro.org>
Newsgroups	linux.kernel
Subject	Re: [PATCH] bpf: convert hashtab lock to raw lock
Date	2015-11-02 18:40 +0100
Message-ID	<qqrfj-8a7-15@gated-at.bofh.it> (permalink)
References	(1 earlier) <qprU5-482-15@gated-at.bofh.it> <qpEHE-3rB-7@gated-at.bofh.it> <qpJHj-6JK-9@gated-at.bofh.it> <qqqVZ-83U-27@gated-at.bofh.it> <qqr5F-871-19@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On 11/2/2015 9:24 AM, Steven Rostedt wrote:
> On Mon, 02 Nov 2015 09:12:29 -0800
> "Shi, Yang" <yang.shi@linaro.org> wrote:
>
>> Yes, it is common practice for converting sleepable spin lock to raw
>> spin lock in -rt to avoid scheduling in atomic context bug.
>
> Note, in a lot of cases we don't just convert spin_locks to raw because
> of atomic context. There's times we need to change the design where the
> lock is not taken in atomic context (switching preempt_disable() to a
> local_lock() for example).

Yes, definitely. Understood.

Thanks,
Yang

>
> But bpf is much like ftrace and kprobes where they can be taken almost
> anywhere, and the do indeed need to be raw.
>
> -- Steve
>

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Thread

Re: [PATCH] bpf: convert hashtab lock to raw lock Daniel Borkmann <daniel@iogearbox.net> - 2015-10-31 20:10 +0100
  Re: [PATCH] bpf: convert hashtab lock to raw lock "Shi, Yang" <yang.shi@linaro.org> - 2015-11-02 18:20 +0100
    Re: [PATCH] bpf: convert hashtab lock to raw lock Steven Rostedt <rostedt@goodmis.org> - 2015-11-02 18:30 +0100
      Re: [PATCH] bpf: convert hashtab lock to raw lock "Shi, Yang" <yang.shi@linaro.org> - 2015-11-02 18:40 +0100
    Re: [PATCH] bpf: convert hashtab lock to raw lock Daniel Borkmann <daniel@iogearbox.net> - 2015-11-02 18:30 +0100

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