Re: [GIT PULL] cputime patch for 2.6.30-rc6

[Peter Zijlstra]

On Tue, 2009-05-19 at 10:49 +0200, Martin Schwidefsky wrote:

> Well, don't do stupid things like that. That falls into the same
> category as programs calling gettimeofday all the time.

Is gtod a global DoS? The worry I have about these cputime
for_each_cpu() loops in the proc code is that any odd unpriv user can
take the whole machine down (provided the machine is large enough).

Granted, this would only be a real problem for SGI and their insane
boxes atm, but it might very well be a problem for us in the near
future, given the rate Intel seems to increase cores.

So, I'm really not objecting too much to the patch at hand, but I'd love
to find a solution to this problem.

My personal favourite is to lower the resolution/accuracy of the answer
the bigger the box gets.
--
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/