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    SubjectRe: [PATCH -V2] acpi: don't cond_resched if irq is disabled
    Hi Xiaotian,

    I think, this is another round of "armor vs. bullet" race... It will hold until
    might_sleep() logic changes again.

    Please consider using preemptible() -- IMHO this is the check we should perform
    in our case of voluntary preemption.

    Regards,
    Alex.


    Xiaotian Feng пишет:
    > commit 8bd108d adds preemption point after each opcode parse, then
    > a sleeping function called from invalid context bug was founded
    > during suspend/resume stage. this was fixed in commit abe1dfa by
    > don't cond_resched when irq_disabled. But recent commit 138d156 changes
    > the behaviour to don't cond_resched when in_atomic. This makes the
    > sleeping function called from invalid context bug happen again, which
    > is reported in http://lkml.org/lkml/2009/12/1/371.
    >
    > This patch also fixes http://bugzilla.kernel.org/show_bug.cgi?id=14483
    >
    > Reported-and-bisected-by: Larry Finger <Larry.Finger@lwfinger.net>
    > Reported-and-bisected-by: Justin P. Mattock <justinmattock@gmail.com>
    > Signed-off-by: Xiaotian Feng <dfeng@redhat.com>
    > Cc: Len Brown <lenb@kernel.org>
    > Cc: Bob Moore <robert.moore@intel.com>
    > Cc: Lin Ming <ming.m.lin@intel.com>
    > Cc: Alexey Starikovskiy <astarikovskiy@suse.de>
    > Cc: Pavel Machek <pavel@ucw.cz>
    > ---
    > include/acpi/platform/aclinux.h | 2 +-
    > 1 files changed, 1 insertions(+), 1 deletions(-)
    >
    > diff --git a/include/acpi/platform/aclinux.h b/include/acpi/platform/aclinux.h
    > index 9d7febd..0946997 100644
    > --- a/include/acpi/platform/aclinux.h
    > +++ b/include/acpi/platform/aclinux.h
    > @@ -152,7 +152,7 @@ static inline void *acpi_os_acquire_object(acpi_cache_t * cache)
    > #include <linux/hardirq.h>
    > #define ACPI_PREEMPTION_POINT() \
    > do { \
    > - if (!in_atomic_preempt_off()) \
    > + if (!in_atomic_preempt_off() && !irqs_disabled()) \
    > cond_resched(); \
    > } while (0)
    >

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