Message-ID: <53AEAD59.5060701@huawei.com>
Date: Sat, 28 Jun 2014 19:56:09 +0800
From: Xie XiuQi <xiexiuqi@huawei.com>
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To: "Luck, Tony" <tony.luck@intel.com>, Steven Rostedt <rostedt@goodmis.org>
CC: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "Frederic Weisbecker" <fweisbec@gmail.com>,
        Ingo Molnar <mingo@redhat.com>, Mauro Chehab <m.chehab@samsung.com>
Subject: Re: [PATCH] time: Provide full featured jiffies_to_nsecs() function
References: <0286550@agluck-desk.sc.intel.com> <53795E3B.9000004@huawei.com> <3908561D78D1C84285E8C5FCA982C28F3280EB34@ORSMSX114.amr.corp.intel.com>
In-Reply-To: <3908561D78D1C84285E8C5FCA982C28F3280EB34@ORSMSX114.amr.corp.intel.com>
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On 2014/5/20 6:35, Luck, Tony wrote:
>> Another problem, maybe we should use get_jiffies_64() instead of jiffies
>> directly here OR we'll meet wraparound problems on 32bit system. But a
>> same problem is that the jiffies_lock is not safe in NMI context...
> 
> To quote Winnie the Pooh - "Bother".
> 
> Can someone think of a clever way to get a sane 64 bit jiffie value on
> 32-bit systems (even when we get an NMI in the middle of updating the
> 64-bit jiffie)?

Hi Tony & Steven,

I've sent a patch to solve this problem, please help to review, thanks.

	http://lkml.org/lkml/2014/6/28/41
	tracing: fix uptime overflow problem

Thanks,
	XiuQi

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