Messages in this thread |  | | | Subject | Re: x86: 4kstacks default | | From | Benjamin Herrenschmidt <> | | Date | Wed, 23 Apr 2008 15:27:01 +1000 | |
On Sat, 2008-04-19 at 16:23 +0200, Ingo Molnar wrote:
> * Andrew Morton <akpm@linux-foundation.org> wrote:
>
> > > config 4KSTACKS
> > > bool "Use 4Kb for kernel stacks instead of 8Kb"
> > > - depends on DEBUG_KERNEL
> > > depends on X86_32
> > > + default y
> >
> > This patch will cause kernels to crash.
>
> what mainline kernels crash and how will they crash? Fedora and other
> distros have had 4K stacks enabled for years:
>
> $ grep 4K /boot/config-2.6.24-9.fc9
> CONFIG_4KSTACKS=y
>
> and we've conducted tens of thousands of bootup tests with all sorts of
> drivers and kernel options enabled and have yet to see a single crash
> due to 4K stacks. So basically the kernel default just follows the
> common distro default now. (distros and users can still disable it)
Do we routinely test nasty scenarii such as a GFP_KERNEL allocation deep
in a call stack trying to swap something out to NFS ?
Ben.
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