Re: [PATCH 2/2] Add a thread cpu time implementation to vDSO

From: Arun Sharma
Date: Mon Dec 12 2011 - 17:16:05 EST


On 12/12/11 1:27 PM, Eric Dumazet wrote:

This only works if CONFIG_X86_L1_CACHE_SHIFT=6

Some configurations have 128 bytes cache lines


I could still handle this case based on compile time math.

But really most modern distros have NR_CPUS> 64

Is 256 the new 64? :)

That'll require 3 more VVAR pages, most of which would be unused on the vast majority of the systems (assuming 32 CPUs or less).

Having the number of VVAR pages configurable at boot time would solve this problem nicely. I think that should be a separate patch.

-Arun
--
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/