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Date: Tue, 28 Feb 2012 09:08:52 +0100
From: Ingo Molnar <mingo@elte.hu>
To: John Stultz <john.stultz@linaro.org>
Cc: lkml <linux-kernel@vger.kernel.org>, Thomas Gleixner <tglx@linutronix.de>,
        Eric Dumazet <eric.dumazet@gmail.com>,
        Richard Cochran <richardcochran@gmail.com>
Subject: Re: [PATCH 3/7] time: Split timekeeper lock into separate
 reader/writer locks
Message-ID: <20120228080851.GD21106@elte.hu>
References: <1330388974-27793-1-git-send-email-john.stultz@linaro.org>
 <1330388974-27793-4-git-send-email-john.stultz@linaro.org>
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* John Stultz <john.stultz@linaro.org> wrote:

> --- a/kernel/time/timekeeping.c
> +++ b/kernel/time/timekeeping.c
> @@ -71,8 +71,9 @@ struct timekeeper {
>  	/* The raw monotonic time for the CLOCK_MONOTONIC_RAW posix clock. */
>  	struct timespec raw_time;
>  
> -	/* Seqlock for all timekeeper values */
> -	seqlock_t lock;
> +	/* locks for timekeeper structure */
> +	seqcount_t rlock;   /* This seqcount serializes readers from updates */
> +	spinlock_t wlock;	/* This spinlock serializes updaters */

Vertical spacing broken again - not just of the fields but of 
the comments as well.

> @@ -576,11 +583,11 @@ u64 timekeeping_max_deferment(void)
>  	unsigned long seq;
>  	u64 ret;
>  	do {

sigh.

Thanks,

	Ingo