Re: [PATCH] NTP: remove clock_was_set() call to prevent deadlock

[Roman Zippel <zippel@linux-m68k.org>]

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.

bye, Roman
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