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    SubjectRe: [PATCH] generic-ipi: add lock context annotations
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    2010-11-23 (화), 12:40 +0300, Dan Carpenter: 
    > On Tue, Nov 23, 2010 at 09:49:56AM +0100, Jens Axboe wrote:
    > > I guess what Peter means is that the fact that the function grabs the
    > > lock is apparent in the code, if sparse was a bit "smarter", it would
    > > see and note this itself.
    >
    > The sparse warning messages should have been included in the commit
    > message. Here they are:
    >
    > kernel/smp.c:513:6: warning: context imbalance in 'ipi_call_lock' - wrong count at exit
    > kernel/smp.c:518:6: warning: context imbalance in 'ipi_call_unlock' - unexpected unlock
    > kernel/smp.c:523:6: warning: context imbalance in 'ipi_call_lock_irq' - wrong count at exit
    > kernel/smp.c:528:6: warning: context imbalance in 'ipi_call_unlock_irq' - unexpected unlock
    >
    > What happens is that sparse *does* see that the locks are unlocked and
    > that's what it complains about.
    >
    > Sparse works before the code is linked so this change doesn't affect
    > anything outside kernel/smp.c. If we added these annotations to
    > include/linux/smp.h then they would be used for checking
    > kernel/smpboot.c
    >
    > regards,
    > dan carpenter
    >

    I tried to annotate declations in include/linux/smp.h but it didn't work
    well. Maybe that's what we need to fix the sparse?

    Anyway, Jens, do you want new patch which includes above warnings?

    Thanks.

    --
    Regards,
    Namhyung Kim



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