Messages in this thread |  | | Date | Thu, 12 Jun 2014 02:22:33 +0200 (CEST) | From | Thomas Gleixner <> | Subject | Re: [patch 13/13] tomoyo: Use sensible time interface |
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On Wed, 11 Jun 2014, John Stultz wrote:
> On Wed, Jun 11, 2014 at 4:59 PM, Thomas Gleixner <tglx@linutronix.de> wrote: > > There is no point in calling gettimeofday if only the seconds part of > > the timespec is used. Use get_seconds() instead. It's not only the > > proper interface it's also faster. > > My only caution here is you only get tick-granular time here. So if > the second rolled over after the last tick, you'd get the previous > second when you call get_seconds(). This can cause some surprising > effects if the get_seconds() return value is mixed with clocksource > granular gettimeofday() calls.
If the whole thing only cares about the seconds value, then where is the problem?
Even if you call gettimeofday() then you still can observe this
gettimeofday(ts) ts.tv_sec = 99 ts.tv_nsec = 999999999
So if you readout the related value ONE nanosecond later, then this value will have ts.tv_sec = 100 ts.tv_nsec = 0
So what's the point? The tomoyo code chose to take seconds granular time stamps for whatever reasons. So it should be able to deal with that, right?
Thanks,
tglx
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