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    SubjectRe: [BUG] next-20081216 - WARNING: at kernel/smp.c:333 smp_call_function_mask

    * Kamalesh Babulal <kamalesh@linux.vnet.ibm.com> wrote:

    > * Sam Ravnborg <sam@ravnborg.org> [2008-12-26 11:27:16]:
    >
    > > On Fri, Dec 26, 2008 at 02:05:47AM -0800, Yinghai Lu wrote:
    > > > Kamalesh Babulal wrote:
    > > > > * Yinghai Lu <yinghai@kernel.org> [2008-12-24 12:34:41]:
    > > > >
    > > > >> --
    > > > >
    > > > > After the applying the patch, the kernel panic's with the same backtrace. The
    > > > > box is running Fedora 5 on it.
    > > > >
    > > >
    > > > please try...
    > > > Ingo, do we need to switch to use #idef and inline function instead?
    > >
    > > I recall David Howells had a similar issue with the bootparamter patch set.
    > > The workaround he used was to add a barrier(); call in the weak function
    > > to avoid the inline.
    > >
    > > [full context kept as I added David to to: list].
    > > Sam
    > >
    >
    > Hi Yinghai,
    >
    > Thanks, after applying the patch, the kernel boot's up fine.

    how about the patch below, does that work too? (after removing Yinghai's
    patch)

    Ingo

    ------------->
    From 0d41e654c877a0de441448ca2f63a72ed11c5d84 Mon Sep 17 00:00:00 2001
    From: Ingo Molnar <mingo@elte.hu>
    Date: Fri, 26 Dec 2008 14:39:51 +0100
    Subject: [PATCH] kbuild, sparseirq: work around GCC bug with __weak aliases

    Impact: fix panic on null pointer with sparseirq

    Certain versions of GCC inline the weak global functions.
    Work it around by marking __weak functions as noinline.

    Signed-off-by: Ingo Molnar <mingo@elte.hu>
    ---
    include/linux/compiler-gcc.h | 8 +++++++-
    1 files changed, 7 insertions(+), 1 deletions(-)

    diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
    index 5c8351b..1ad72e6 100644
    --- a/include/linux/compiler-gcc.h
    +++ b/include/linux/compiler-gcc.h
    @@ -41,11 +41,17 @@

    #define __deprecated __attribute__((deprecated))
    #define __packed __attribute__((packed))
    -#define __weak __attribute__((weak))
    #define __naked __attribute__((naked))
    #define __noreturn __attribute__((noreturn))

    /*
    + * Mark weak aliases also noinline, because some GCC versions
    + * incorrectly inline weak aliases (even when a non-weak variant
    + * is there) and thus cause crashes:
    + */
    +#define __weak __attribute__((weak)) noinline
    +
    +/*
    * From the GCC manual:
    *
    * Many functions have no effects except the return value and their

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      Last update: 2008-12-26 16:39    [W:0.032 / U:0.176 seconds]
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