Re: udelay function delays the wrong time interval inmultiprocessor system, if ARCH_HAS_READ_CURRENT_TIMER is notdefined and on current timer is used.

[Russell King - ARM Linux]

On Sat, Mar 16, 2013 at 12:08:54AM +0800, chpoph wrote:
> If ARCH_HAS_READ_CURRENT_TIMER is not defined and on current timer is
> used for udelay, then __loop_delay and __loop_const_udelay is used to
> delay a specific time interval.  but in delay-loop.S, loops_per_jiffy
> (not per cpu data) is used to calculate the number of loops. in SMP
> system, udelay delays the wrong time interval if two cpus running at
> different frequency.

We don't support different CPUs running at different frequencies with
the delay loop.  Sorry.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/