Re: [2.6 patch] i386: always use 4k stacks

Andi Kleen
2005-12-17T17:44:20Z

Kyle Moffett <mrmacman_g4@mac.com> writes:

> On Dec 16, 2005, at 10:35, Diego Calleja wrote:
> > I know, but there's too much resistance to the "pure" 4kb patch.
>
> I have yet to see any resistance to the 4Kb patch this time around
> that was not "*whine* don't break my ndiswrapper plz".

My comment from last time about the missing safety net still applies 100%.

Kernel code is getting more complex all the time and running with
very tight stack is just risky.

> The point is to force it in -mm so most people can't just disable it
> because it fixes their problem. We want 8k stacks to go away, and

Who is we? And why?

About the only half way credible arguments I've seen for it were:

- "it might reduce stalls in the VM with order 1". Didn't quite
convince me because there were no numbers presented and at least on
x86-64 I've never noticed or got reported significant stalls because
of this.

- "it allows more threads for 32bit which might run out of lowmem" - i
think everybody agrees that the 10k threads case is not really
something to encourage. And even when you want to add it then only a factor
two increase (which this patch brings) is not really too helpful.

The main argument thrown around seems to be "but it will break
binary only modules" - while I'm not fully unsympathetic I don't
think technical issues in the kernel should be guided by
such political considerations.

I suspect you will be reposting it so often till the voices
of reasons get tired?

-Andi