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From: "Shi, Yang" <yang.shi@linaro.org>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>,
	Alexei Starovoitov <alexei.starovoitov@gmail.com>,
	ast@kernel.org, linux-kernel@vger.kernel.org,
	linux-rt-users@vger.kernel.org, netdev@vger.kernel.org,
	linaro-kernel@lists.linaro.org
Subject: Re: [PATCH] bpf: convert hashtab lock to raw lock
Date: Mon, 02 Nov 2015 09:31:50 -0800	[thread overview]
Message-ID: <56379E06.3040008@linaro.org> (raw)
In-Reply-To: <20151102122405.56dd97a1@gandalf.local.home>

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
>


  reply	other threads:[~2015-11-02 17:31 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-10-30 22:16 [PATCH] bpf: convert hashtab lock to raw lock Yang Shi
2015-10-31  0:03 ` Alexei Starovoitov
2015-10-31 13:47   ` Steven Rostedt
2015-10-31 18:37     ` Daniel Borkmann
2015-11-02 17:12       ` Shi, Yang
2015-11-02 17:24         ` Steven Rostedt
2015-11-02 17:31           ` Shi, Yang [this message]
2015-11-02 17:28         ` Daniel Borkmann
2015-11-01 22:56     ` Alexei Starovoitov
2015-11-02  8:59       ` Thomas Gleixner
2015-11-02 17:09         ` Shi, Yang
2015-11-02 20:47 ` David Miller

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