linux-kernel - Re: [RESEND PATCH v6] x86/hpet: Reduce HPET counter read contention

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Message-ID: <57CEF892.3090301@hpe.com>
Date:   Tue, 6 Sep 2016 13:10:42 -0400
From:   Waiman Long <waiman.long@....com>
To:     Thomas Gleixner <tglx@...utronix.de>
CC:     Ingo Molnar <mingo@...hat.com>, "H. Peter Anvin" <hpa@...or.com>,
        <linux-kernel@...r.kernel.org>, <x86@...nel.org>,
        Borislav Petkov <bp@...e.de>,
        Andy Lutomirski <luto@...nel.org>,
        Dave Hansen <dave.hansen@...el.com>,
        Prarit Bhargava <prarit@...hat.com>,
        Scott J Norton <scott.norton@....com>,
        Douglas Hatch <doug.hatch@....com>,
        Randy Wright <rwright@....com>
Subject: Re: [RESEND PATCH v6] x86/hpet: Reduce HPET counter read contention

On 09/06/2016 11:50 AM, Thomas Gleixner wrote:
> On Tue, 6 Sep 2016, Waiman Long wrote:
>> This is done by using a combination word with a sequence number and
>> a bit lock. The CPU that gets the bit lock will be responsible for
>> reading the HPET counter and update the sequence number. The others
>> will monitor the change in sequence number and grab the HPET counter
>> value accordingly. This change is only enabled on SMP configuration.
> That hardly matches the implementation.
>
> Thanks,
>
> 	tglx
Sorry, I forgot to update the change log accordingly. Will send out a 
new patch to address that.

Cheers,
Longman