Re: [PATCH] CFS: Fix missing digit off in wmult table

[Matt Mackall]

On Mon, Jul 16, 2007 at 04:01:17PM +0200, Roman Zippel wrote:
> Hi,
> 
> On Mon, 16 Jul 2007, Ingo Molnar wrote:
> 
> > to sum it up: a nice +19 task (the most commonly used nice level in 
> > practice) gets 9.1%, 3.9%, 3.1% of CPU time on the old scheduler, 
> > depending on the value of HZ. This is quite inconsistent and illogical.
> 
> You're correct that you can find artifacts in the extreme cases, it's 
> subjective whether this is a serious problem.
> It's nice that these artifacts are gone, but that still doesn't explain 
> why this ratio had to be increase that much from around 1:10 to 1:69.

More dynamic range is better? If you actually want a task to get 20x
the CPU time of another, the older scheduler doesn't really allow it.

Getting 1/69th of a modern CPU is still a fair number of cycles.
Nevermind 1/69th of a machine with > 64 cores.

-- 
Mathematics is the supreme nostalgia of our time.
-
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/