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Subject: Re: [PATCH v10 03/11] arm64: Make get_wchan() use arch_stack_walk()
To:     Mark Brown <broonie@kernel.org>
Cc:     mark.rutland@arm.com, jpoimboe@redhat.com, ardb@kernel.org,
        nobuta.keiya@fujitsu.com, sjitindarsingh@gmail.com,
        catalin.marinas@arm.com, will@kernel.org, jmorris@namei.org,
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        live-patching@vger.kernel.org, linux-kernel@vger.kernel.org
References: <c05ce30dcc9be1bd6b5e24a2ca8fe1d66246980b>
 <20211015025847.17694-1-madvenka@linux.microsoft.com>
 <20211015025847.17694-4-madvenka@linux.microsoft.com>
 <YXA/eepRCCzL+/jD@sirena.org.uk>
From:   "Madhavan T. Venkataraman" <madvenka@linux.microsoft.com>
Message-ID: <217ce31e-222b-cc10-f5e1-027e00a49cd4@linux.microsoft.com>
Date:   Thu, 21 Oct 2021 07:30:28 -0500
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I will take a look at what Peter has done and will coordinate with him.

Thanks.

Madhavan

On 10/20/21 11:10 AM, Mark Brown wrote:
> On Thu, Oct 14, 2021 at 09:58:39PM -0500, madvenka@linux.microsoft.com wrote:
>> From: "Madhavan T. Venkataraman" <madvenka@linux.microsoft.com>
>>
>> Currently, get_wchan() in ARM64 code walks the stack using start_backtrace()
>> and unwind_frame(). Make it use arch_stack_walk() instead. This makes
>> maintenance easier.
> 
> This overlaps with some very similar updates that Peter Zijlstra is
> working on which addresses some existing problems with wchan:
> 
> 	https://lore.kernel.org/all/20211008111527.438276127@infradead.org/
> 
> It probably makes sense for you to coordinate with Peter here, some of
> that series is already merged up to his patch 6 which looks very
> similar to what you've got here.  In that thread you'll see that Mark
> Rutland spotted an issue with the handling of __switch_to() on arm64
> which probably also applies to your change.
> 
> 
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