* Steven Rostedt <[EMAIL PROTECTED]> wrote:
> Ingo,
>
> I wasn't able to turn on latency tracing on a x86_64 box. Using logdev
> to see what was happening, I found that echoing 0 into
> /proc/sys/kernel/preempt_max_latency would only change the max from
> -1ULL to 0xffffffff00000000. Which would keep the max pretty high
> still.
ah! This should explain Roland Dreier's report about tracing not working
on x86_64.
> The problem is in sysctl.c where preempt_max_latency can be modified.
> On systems where cycle_t is greater than the size of int (x86_64) we
> only write to the 4 LSB.
>
> Here's the patch:
thanks, applied.
Ingo
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