Re: [PATCH 4/6] x86/cpufreq: use cpumask_copy instead of =

From: Yinghai Lu
Date: Tue Jun 09 2009 - 04:15:06 EST


Rusty Russell wrote:
On Sun, 7 Jun 2009 07:23:52 am Yinghai Lu wrote:
so later could use nr_cpumask_bits in cpumask_size when MAXSMP is used

I have a (more ambitious) patch for this in my queue, which weans it off this
entirely:

Subject: cpumask: avoid playing with cpus_allowed in powernow-k8.c
From: Rusty Russell <rusty@xxxxxxxxxxxxxxx>

It's generally a very bad idea to mug some process's cpumask: it could
legitimately and reasonably be changed by root, which could break us
(if done before our code) or them (if we restore the wrong value).

I use work_on_cpu, which is slightly less efficient than the old code,
but the code is complex enough that using smp_call_function_single()
is not trivial.

will be in .31?

YH
--
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/