|| ||Andrew Morton <email@example.com>|
|| ||Ingo Molnar <firstname.lastname@example.org>|
|| ||Re: x86: 4kstacks default|
|| ||Sat, 19 Apr 2008 10:49:11 -0700|
|| ||email@example.com, firstname.lastname@example.org,
> On Sat, 19 Apr 2008 16:23:29 +0200 Ingo Molnar <email@example.com> wrote:
> * Andrew Morton <firstname.lastname@example.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?
There has been a dribble of reports - I don't have the links handy, nor did
I search for them.
> Fedora and other
> distros have had 4K stacks enabled for years:
> $ grep 4K /boot/config-2.6.24-9.fc9
> 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.
I doubt if you're testing things like nfsd-on-xfs-on-md-on-porky-scsi-driver.
Enable CONFIG_DEBUG_STACK_USAGE. Monitor the results. It's so scary that
I wonder if the feature is busted.
> So basically the kernel default just follows the
> common distro default now. (distros and users can still disable it)
Apparently not. I wouldn't enable it if I had a distro.
Anyway. We should be having this sort of discussion _before_ a patch
gets merged, no?