Re: [PATCH] Fix booting pentium+ with dodgy TSC

From: Rusty Russell
Date: Sun Apr 06 2008 - 16:29:41 EST


On Sunday 06 April 2008 21:22:08 Ingo Molnar wrote:
> * Rusty Russell <rusty@xxxxxxxxxxxxxxx> wrote:
> > Linus please apply. Almost by definition this patch can't make things
> > worse.
>
> well, while i agree with the patch it could make things worse. In this
> case it can cause code that has been compiled to rely on TSC to
> malfunction. For if sched_clock() was using cpu_has_tsc it could return
> 0 all the time, breaking the scheduler without the user having a clear
> idea why it broke. It isnt, and sched_clock() will work fine, but still,
> your "this cant make things worse" statement is not completely correct.

Hence the "almost". It can't break machines, but it could make the problem
harder to diagnose. Given that it will unbreak at least one machine, I'm
reasonably confident it's a win :)

> Acked-by: Ingo Molnar <mingo@xxxxxxx>

Thanks!
Rusty.
--
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/