Messages in this thread | | | Date | Sat, 19 Apr 2008 10:49:11 -0700 | From | Andrew Morton <> | Subject | Re: x86: 4kstacks default |
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> On Sat, 19 Apr 2008 16:23:29 +0200 Ingo Molnar <mingo@elte.hu> 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?
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 > 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.
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?
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