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    SubjectRe: x86: 4kstacks default
    > 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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