Re: [PATCH 12/13] hrtimer: optimize hrtimer_get_remaining
From: Ingo Molnar
Date: Mon Feb 13 2006 - 09:12:29 EST
* Roman Zippel <zippel@xxxxxxxxxxxxxx> wrote:
> hrtimer_get_remaining doesn't need to lock the hrtimer_base to read
> the time. Also use hrtimer_get_remaining at two other places.
nack - it's not only about ->get_time() atomicity:
> - base = lock_hrtimer_base(timer, &flags);
> - rem = ktime_sub(timer->expires, timer->base->get_time());
> - unlock_hrtimer_base(timer, &flags);
timer->expires is a 64-bit value, which might be read nonatomically on
32-bit platforms. Wherever it's safe, we already open-code this
ktime_sub() - if you find more places then please do it that way.
definitely not something for v2.6.16.
Ingo
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