On Wed, 2007-07-04 at 13:06 +0200, Roman Zippel wrote:
> Hi,
>
> On Tuesday 03 July 2007, Thomas Gleixner wrote:
>
> > The clock_was_set() call in seconds_overflow() which happens only when
> > leap seconds are inserted / deleted is wrong in two aspects:
> >
> > 1. it results in a call to on_each_cpu() with interrupts disabled
> > 2. it is potential deadlock source vs. call_lock in smp_call_function()
> >
> > The only possible side effect of the removal might be, that an absolute
> > CLOCK_REALTIME timer fires 1 second too late, in the rare case of leap
> > second deletion and an absolute CLOCK_REALTIME timer which expires in
> > the affected time frame. It will never fire too early.
>
> That's a bit of an easy solution and doesn't fix the real problem. The
> clock_was_set() calls were correct, what's broken is the locking. Why wasn't
> that fixed instead?
> I would at least like to see a comment there, why these calls were removed.
We can not fix the locking that late in the cycle. I doubt that we can
fix it at all, as smp_call_function _must_ run with interrupts enabled,
therefor it can not run in interrupt context. It needs to run from
thread context only.
tglx
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
