Re: [PATCH] sched: provide scheduler_ipi() callback in response to smp_send_reschedule()

On 01/17/2011 03:07 AM, 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.

I visited existing smp_send_reschedule() implementations and tried to
add a call to scheduler_ipi() in their handler part, but esp. for MIPS
I'm not quite sure I actually got all of them.

Also, while reading through all this, I noticed the blackfin SMP code
looks to be broken, it simply discards any IPI when low on memory.

Signed-off-by: Peter Zijlstra<redacted>
---
  arch/alpha/kernel/smp.c         |    1 +
  arch/arm/kernel/smp.c           |    1 +
  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          |    2 +-
  arch/mips/kernel/smtc.c         |    1 +
  arch/mips/sibyte/bcm1480/smp.c  |    7 +++----
  arch/mips/sibyte/sb1250/smp.c   |    7 +++----

[...]

Peter,

You will also have to patch the mailbox_interrupt() function in 
arch/mips/cavium-octeon/smp.c

David Daney.