linux-kernel - Re: [PATCH v2] arm64: Fix task tracing

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Message-ID: <51656524.10708@codeaurora.org>
Date:	Wed, 10 Apr 2013 09:12:04 -0400
From:	Christopher Covington <cov@...eaurora.org>
To:	Will Deacon <will.deacon@....com>
CC:	Catalin Marinas <Catalin.Marinas@....com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"linux-arm-kernel@...ts.infradead.org" 
	<linux-arm-kernel@...ts.infradead.org>,
	"linux-arm-msm@...r.kernel.org" <linux-arm-msm@...r.kernel.org>
Subject: Re: [PATCH v2] arm64: Fix task tracing

Hi Will,

On 04/10/2013 07:41 AM, Will Deacon wrote:
> On Tue, Apr 09, 2013 at 01:33:34PM +0100, Christopher Covington wrote:
>> For accurate accounting pass contextidr_thread_switch the prev
>> task pointer, since cpu_switch_to has at that point changed the
>> the stack pointer.
>>
>> Signed-off-by: Christopher Covington <cov@...eaurora.org>
> 
> Thanks Christopher -- I assume that using prev did resolve your issues?

Yes indeed. We're now able to see in simulation that if a userspace process
uses 100% CPU, its thread ID, rather than what was usually some random
kthread, gets written out most of the time. I donno if that meets your
criteria for a "real" use case, but I hope it's at least sufficient testing of
the code for now.

Thanks,
Christopher

-- 
Employee of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
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