Re: [PATCH 1/3] signal: sys_rt_sigtimedwait: simplify the timeoutlogic

From: Tejun Heo
Date: Mon Apr 25 2011 - 07:37:55 EST


On Sat, Apr 23, 2011 at 07:59:22PM +0200, Oleg Nesterov wrote:
> No functional changes, cleanup compat_sys_rt_sigtimedwait() and
> sys_rt_sigtimedwait().
>
> Calculate the timeout before we take ->siglock, this simplifies and
> lessens the code. Use timespec_valid() to check the timespec.
>
> I don't understand why we are adding (ts.tv_sec || ts.tv_nsec) to
> timespec_to_jiffies(&ts). Perhaps to ensure we will sleep at least
> one jiffy if ts != 0? But in this case we should only check tv_nsec,
> I don't think timespec_to_jiffies() can return zero if tv_sec != 0.
> In fact I suspect timespec_to_jiffies() can only return zero if
> tv_sec == tv_nsec == 0 because we add "TICK_NSEC - 1", but I am not
> sure I understand correctly this math.
>
> Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>

Acked-by: Tejun Heo <tj@xxxxxxxxxx>

It might be a good idea to note the weird jiffies calculation with a
comment?

Thanks.

--
tejun
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