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From: Jia-Ju Bai <baijiaju1990@gmail.com>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: ning.sun@intel.com, mingo@redhat.com, hpa@zytor.com,
	x86@kernel.org, tboot-devel@lists.sourceforge.net,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] kernel: x86: tboot: Replace mdelay with usleep_range in tboot_wait_for_aps
Date: Wed, 24 Jan 2018 21:37:46 +0800	[thread overview]
Message-ID: <fc5e01ed-e360-5d48-01ea-dbcafb6cf7f9@gmail.com> (raw)
In-Reply-To: <alpine.DEB.2.20.1801241246350.1997@nanos>


On 2018/1/24 19:47, Thomas Gleixner wrote:
> On Wed, 24 Jan 2018, Jia-Ju Bai wrote:
>
>> The function tboot_wait_for_aps is not called in atomic context.
>> Thus mdelay can be replaced with usleep_range, to reduce busy wait.
> And how did you establish that it's not called in atomic context?
>
> Thanks,
>
> 	tglx

It is reported by a static analysis tool written by myself.
This tool finds that mdelay in tboot_wait_for_aps is not called by 
holding a spinlock or in an interrupt handler, thus mdelay can be replaced.


Thanks,
Jia-Ju Bai

  reply	other threads:[~2018-01-24 13:38 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-01-24  1:58 [PATCH] kernel: x86: tboot: Replace mdelay with usleep_range in tboot_wait_for_aps Jia-Ju Bai
2018-01-24 11:47 ` Thomas Gleixner
2018-01-24 13:37   ` Jia-Ju Bai [this message]
2018-01-24 17:20     ` Sun, Ning
2018-01-25  9:35       ` Thomas Gleixner

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