Re: [BENCHMARK] nproc: netlink access to /proc information

Paulo Marques
2004-08-30T12:23:53Z

William Lee Irwin III wrote:
> Albert Cahalan wrote:
>
>>>This is crummy. It's done for wchan, since that is so horribly
>>>expensive, but I'm not liking the larger race condition window.
>>>Remember that PIDs get reused. There isn't a generation counter
>>>or UUID that can be checked.
>
>
> On Mon, Aug 30, 2004 at 11:31:43AM +0100, Paulo Marques wrote:
>
>>I just wanted to call your attention to the kallsyms speedup patch that
>>is now on the -mm tree.
>>It should improve wchan speed. My benchmarks for kallsyms_lookup (the
>>function that was responsible for the wchan time) went from 1340us to 0.5us.
>>So maybe this is enough not to make wchan a special case anymore...
>
>
> This seems to go wrong on big-endian machines; any chance you could look
> over your stuff and try to figure out what endianness issues it may have?

I went over the code but at a first glance couldn't find a notorius
trouble spot. I don't have big-endian hardware myself so this is hard to
test.

Just a few questions to help me out in finding the problem:

- is this really an endianess problem or is it a 64-bit integer problem?

- are you cross compiling the kernel?

Thanks in advance,

--
Paulo Marques - www.grupopie.com

To err is human, but to really foul things up requires a computer.
Farmers' Almanac, 1978