Commit 184748cc authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

sched: Provide scheduler_ipi() callback in response to smp_send_reschedule() 



For future rework of try_to_wake_up() we'd like to push part of that
function 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: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
Acked-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
Acked-by: default avatarChris Metcalf <cmetcalf@tilera.com>
Acked-by: default avatarJesper Nilsson <jesper.nilsson@axis.com>
Acked-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
Reviewed-by: default avatarFrank Rowand <frank.rowand@am.sony.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20110405152728.744338123@chello.nl
parent a4c98f8b

arch/alpha/kernel/smp.c

+1 −2
Original line number Diff line number Diff line
@@ -585,8 +585,7 @@ handle_ipi(struct pt_regs *regs) 


		switch (which) {

		case IPI_RESCHEDULE:

			/* Reschedule callback.  Everything to be done

			   is done by the interrupt return path.  */

			scheduler_ipi();

			break;



		case IPI_CALL_FUNC:

arch/arm/kernel/smp.c

+1 −4
Original line number Diff line number Diff line
@@ -560,10 +560,7 @@ asmlinkage void __exception_irq_entry do_IPI(int ipinr, struct pt_regs *regs) 
		break;



	case IPI_RESCHEDULE:

		/*

		 * nothing more to do - eveything is

		 * done on the interrupt return path

		 */

		scheduler_ipi();

		break;



	case IPI_CALL_FUNC:

arch/blackfin/mach-common/smp.c

+3 −0
Original line number Diff line number Diff line
@@ -164,6 +164,9 @@ static irqreturn_t ipi_handler_int1(int irq, void *dev_instance) 
	while (msg_queue->count) {

		msg = &msg_queue->ipi_message[msg_queue->head];

		switch (msg->type) {

		case BFIN_IPI_RESCHEDULE:

			scheduler_ipi();

			break;

		case BFIN_IPI_CALL_FUNC:

			spin_unlock_irqrestore(&msg_queue->lock, flags);

			ipi_call_function(cpu, msg);

arch/cris/arch-v32/kernel/smp.c

+8 −5
Original line number Diff line number Diff line
@@ -342,6 +342,9 @@ irqreturn_t crisv32_ipi_interrupt(int irq, void *dev_id) 


	ipi = REG_RD(intr_vect, irq_regs[smp_processor_id()], rw_ipi);



	if (ipi.vector & IPI_SCHEDULE) {

		scheduler_ipi();

	}

	if (ipi.vector & IPI_CALL) {

		func(info);

	}

arch/ia64/kernel/irq_ia64.c

+2 −0
Original line number Diff line number Diff line
@@ -31,6 +31,7 @@ 
#include <linux/irq.h>

#include <linux/ratelimit.h>

#include <linux/acpi.h>

#include <linux/sched.h>



#include <asm/delay.h>

#include <asm/intrinsics.h>
@@ -496,6 +497,7 @@ ia64_handle_irq (ia64_vector vector, struct pt_regs *regs) 
			smp_local_flush_tlb();

			kstat_incr_irqs_this_cpu(irq, desc);

		} else if (unlikely(IS_RESCHEDULE(vector))) {

			scheduler_ipi();

			kstat_incr_irqs_this_cpu(irq, desc);

		} else {

			ia64_setreg(_IA64_REG_CR_TPR, vector);

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