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Message-ID: <tip-47o4m03citrfg9y1vxic5asb@git.kernel.org>
Date: Tue, 11 Feb 2014 04:18:08 -0800
From: tip-bot for Nicolas Pitre <tipbot@...or.com>
To: linux-tip-commits@...r.kernel.org
Cc: linux-kernel@...r.kernel.org, hpa@...or.com, mingo@...nel.org,
peterz@...radead.org, nicolas.pitre@...aro.org,
lethal@...ux-sh.org, benh@...nel.crashing.org,
linux@....linux.org.uk, preeti@...ux.vnet.ibm.com, nico@...aro.org,
tglx@...utronix.de, rjw@...ysocki.net, daniel.lezcano@...aro.org
Subject: [tip:sched/core] sched/idle, PPC:
Remove redundant cpuidle_idle_call()
Commit-ID: d8c6ad3184ca6516a5cf457af1afaa293d8f09c0
Gitweb: http://git.kernel.org/tip/d8c6ad3184ca6516a5cf457af1afaa293d8f09c0
Author: Nicolas Pitre <nicolas.pitre@...aro.org>
AuthorDate: Wed, 29 Jan 2014 12:45:10 -0500
Committer: Ingo Molnar <mingo@...nel.org>
CommitDate: Tue, 11 Feb 2014 09:58:24 +0100
sched/idle, PPC: Remove redundant cpuidle_idle_call()
The core idle loop now takes care of it. However a few things need
checking:
- Invocation of cpuidle_idle_call() in pseries_lpar_idle() happened
through arch_cpu_idle() and was therefore always preceded by a call
to ppc64_runlatch_off(). To preserve this property now that
cpuidle_idle_call() is invoked directly from core code, a call to
ppc64_runlatch_off() has been added to idle_loop_prolog() in
platforms/pseries/processor_idle.c.
- Similarly, cpuidle_idle_call() was followed by ppc64_runlatch_off()
so a call to the later has been added to idle_loop_epilog().
- And since arch_cpu_idle() always made sure to re-enable IRQs if they
were not enabled, this is now
done in idle_loop_epilog() as well.
The above was made in order to keep the execution flow close to the
original. I don't know if that was strictly necessary. Someone well
aquainted with the platform details might find some room for possible
optimizations.
Signed-off-by: Nicolas Pitre <nico@...aro.org>
Reviewed-by: Preeti U Murthy <preeti@...ux.vnet.ibm.com>
Cc: "Rafael J. Wysocki" <rjw@...ysocki.net>
Cc: Daniel Lezcano <daniel.lezcano@...aro.org>
Cc: linux-arm-kernel@...ts.infradead.org
Cc: linuxppc-dev@...ts.ozlabs.org
Cc: linux-sh@...r.kernel.org
Cc: linux-pm@...r.kernel.org
Cc: Russell King <linux@....linux.org.uk>
Cc: linaro-kernel@...ts.linaro.org
Cc: Benjamin Herrenschmidt <benh@...nel.crashing.org>
Cc: Paul Mundt <lethal@...ux-sh.org>
Signed-off-by: Peter Zijlstra <peterz@...radead.org>
Link: http://lkml.kernel.org/n/tip-47o4m03citrfg9y1vxic5asb@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@...nel.org>
---
arch/powerpc/platforms/pseries/setup.c | 34 ++++++++++++++--------------------
drivers/cpuidle/cpuidle-pseries.c | 5 +++++
2 files changed, 19 insertions(+), 20 deletions(-)
diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
index 8e639d7..c737d55 100644
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -39,7 +39,6 @@
#include <linux/irq.h>
#include <linux/seq_file.h>
#include <linux/root_dev.h>
-#include <linux/cpuidle.h>
#include <linux/of.h>
#include <linux/kexec.h>
@@ -356,29 +355,24 @@ early_initcall(alloc_dispatch_log_kmem_cache);
static void pseries_lpar_idle(void)
{
- /* This would call on the cpuidle framework, and the back-end pseries
- * driver to go to idle states
+ /*
+ * Default handler to go into low thread priority and possibly
+ * low power mode by cedeing processor to hypervisor
*/
- if (cpuidle_idle_call()) {
- /* On error, execute default handler
- * to go into low thread priority and possibly
- * low power mode by cedeing processor to hypervisor
- */
- /* Indicate to hypervisor that we are idle. */
- get_lppaca()->idle = 1;
+ /* Indicate to hypervisor that we are idle. */
+ get_lppaca()->idle = 1;
- /*
- * Yield the processor to the hypervisor. We return if
- * an external interrupt occurs (which are driven prior
- * to returning here) or if a prod occurs from another
- * processor. When returning here, external interrupts
- * are enabled.
- */
- cede_processor();
+ /*
+ * Yield the processor to the hypervisor. We return if
+ * an external interrupt occurs (which are driven prior
+ * to returning here) or if a prod occurs from another
+ * processor. When returning here, external interrupts
+ * are enabled.
+ */
+ cede_processor();
- get_lppaca()->idle = 0;
- }
+ get_lppaca()->idle = 0;
}
/*
diff --git a/drivers/cpuidle/cpuidle-pseries.c b/drivers/cpuidle/cpuidle-pseries.c
index 7ab564a..d486489 100644
--- a/drivers/cpuidle/cpuidle-pseries.c
+++ b/drivers/cpuidle/cpuidle-pseries.c
@@ -29,6 +29,7 @@ static struct cpuidle_state *cpuidle_state_table;
static inline void idle_loop_prolog(unsigned long *in_purr)
{
+ ppc64_runlatch_off();
*in_purr = mfspr(SPRN_PURR);
/*
* Indicate to the HV that we are idle. Now would be
@@ -45,6 +46,10 @@ static inline void idle_loop_epilog(unsigned long in_purr)
wait_cycles += mfspr(SPRN_PURR) - in_purr;
get_lppaca()->wait_state_cycles = cpu_to_be64(wait_cycles);
get_lppaca()->idle = 0;
+
+ if (irqs_disabled())
+ local_irq_enable();
+ ppc64_runlatch_on();
}
static int snooze_loop(struct cpuidle_device *dev,
--
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