Messages in this thread | | | Date | Thu, 10 Mar 2011 17:36:08 -0800 | From | Frank Rowand <> | Subject | Re: [PATCH 01/22] sched: Provide scheduler_ipi() callback in response to smp_send_reschedule() |
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On 03/02/11 09:38, Peter Zijlstra wrote: > For future rework of try_to_wake_up() we'd like to push part of that > onto the CPU the task is actually going to run on, in order to do so we > need a generic callback from the existing scheduler IPI. > > This patch introduces such a generic callback: scheduler_ipi() and > implements it as a NOP. > > BenH notes: PowerPC might use this IPI on offline CPUs under rare > conditions!! > > Acked-by: Russell King <rmk+kernel@arm.linux.org.uk> > Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> > Acked-by: Chris Metcalf <cmetcalf@tilera.com> > Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> > Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> > Signed-off-by: Ralf Baechle <ralf@linux-mips.org> > Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> > LKML-Reference: <new-submission> > --- > arch/alpha/kernel/smp.c | 3 +-- > arch/arm/kernel/smp.c | 5 +---- > arch/blackfin/mach-common/smp.c | 3 +++ > arch/cris/arch-v32/kernel/smp.c | 13 ++++++++----- > arch/ia64/kernel/irq_ia64.c | 2 ++ > arch/ia64/xen/irq_xen.c | 10 +++++++++- > arch/m32r/kernel/smp.c | 4 +--- > arch/mips/cavium-octeon/smp.c | 2 ++ > arch/mips/kernel/smtc.c | 2 +- > arch/mips/mti-malta/malta-int.c | 2 ++ > arch/mips/pmc-sierra/yosemite/smp.c | 4 ++++ > arch/mips/sgi-ip27/ip27-irq.c | 2 ++ > arch/mips/sibyte/bcm1480/smp.c | 7 +++---- > arch/mips/sibyte/sb1250/smp.c | 7 +++---- > arch/mn10300/kernel/smp.c | 5 +---- > arch/parisc/kernel/smp.c | 5 +---- > arch/powerpc/kernel/smp.c | 3 ++- > arch/s390/kernel/smp.c | 6 +++--- > arch/sh/kernel/smp.c | 2 ++ > arch/sparc/kernel/smp_32.c | 2 +- > arch/sparc/kernel/smp_64.c | 1 + > arch/tile/kernel/smp.c | 6 +----- > arch/um/kernel/smp.c | 2 +- > arch/x86/kernel/smp.c | 5 ++--- > arch/x86/xen/smp.c | 5 ++--- > include/linux/sched.h | 1 + > 26 files changed, 60 insertions(+), 49 deletions(-) >
< snip >
In this patch the tabs turned into spaces. (None of the other patches have this problem.)
> Index: linux-2.6/arch/sparc/kernel/smp_32.c > =================================================================== > --- linux-2.6.orig/arch/sparc/kernel/smp_32.c > +++ linux-2.6/arch/sparc/kernel/smp_32.c > @@ -125,7 +125,7 @@ struct linux_prom_registers smp_penguin_ > > void smp_send_reschedule(int cpu) > { > - /* See sparc64 */ > + scheduler_ipi(); > }
If I understand correctly, this is calling scheduler_ipi() on the cpu that should be sending an IPI, not on the cpu receiving the IPI. If so, smp_send_reschedule() needs to send an IPI, and the scheduler_ipi() put in the place where the IPI is processed.
-Frank
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