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authorAnton Blanchard <anton@samba.org>2005-07-07 17:56:33 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2005-07-07 18:23:41 -0700
commit050a09389e045f37e5bf08718cf36909766e20d1 (patch)
tree55911d552e81729ddf825b44463805ade84eb1f0 /arch
parent[PATCH] ppc64: iSeries idle fixups (diff)
downloadlinux-dev-050a09389e045f37e5bf08718cf36909766e20d1.tar.xz
linux-dev-050a09389e045f37e5bf08718cf36909766e20d1.zip
[PATCH] ppc64: pSeries idle fixups
- separate out sleep logic in dedicated_idle, it was so far indented that it got squashed against the right side of the screen. - add runlatch support, looping on runlatch disable. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/ppc64/kernel/pSeries_setup.c113
1 files changed, 62 insertions, 51 deletions
diff --git a/arch/ppc64/kernel/pSeries_setup.c b/arch/ppc64/kernel/pSeries_setup.c
index 3f3be8ae9351..5bec956e44a0 100644
--- a/arch/ppc64/kernel/pSeries_setup.c
+++ b/arch/ppc64/kernel/pSeries_setup.c
@@ -83,8 +83,8 @@ int fwnmi_active; /* TRUE if an FWNMI handler is present */
extern void pSeries_system_reset_exception(struct pt_regs *regs);
extern int pSeries_machine_check_exception(struct pt_regs *regs);
-static int shared_idle(void);
-static int dedicated_idle(void);
+static int pseries_shared_idle(void);
+static int pseries_dedicated_idle(void);
static volatile void __iomem * chrp_int_ack_special;
struct mpic *pSeries_mpic;
@@ -238,10 +238,10 @@ static void __init pSeries_setup_arch(void)
if (cur_cpu_spec->firmware_features & FW_FEATURE_SPLPAR) {
if (get_paca()->lppaca.shared_proc) {
printk(KERN_INFO "Using shared processor idle loop\n");
- ppc_md.idle_loop = shared_idle;
+ ppc_md.idle_loop = pseries_shared_idle;
} else {
printk(KERN_INFO "Using dedicated idle loop\n");
- ppc_md.idle_loop = dedicated_idle;
+ ppc_md.idle_loop = pseries_dedicated_idle;
}
} else {
printk(KERN_INFO "Using default idle loop\n");
@@ -438,15 +438,47 @@ static int __init pSeries_probe(int platform)
DECLARE_PER_CPU(unsigned long, smt_snooze_delay);
-int dedicated_idle(void)
+static inline void dedicated_idle_sleep(unsigned int cpu)
+{
+ struct paca_struct *ppaca = &paca[cpu ^ 1];
+
+ /* Only sleep if the other thread is not idle */
+ if (!(ppaca->lppaca.idle)) {
+ local_irq_disable();
+
+ /*
+ * We are about to sleep the thread and so wont be polling any
+ * more.
+ */
+ clear_thread_flag(TIF_POLLING_NRFLAG);
+
+ /*
+ * SMT dynamic mode. Cede will result in this thread going
+ * dormant, if the partner thread is still doing work. Thread
+ * wakes up if partner goes idle, an interrupt is presented, or
+ * a prod occurs. Returning from the cede enables external
+ * interrupts.
+ */
+ if (!need_resched())
+ cede_processor();
+ else
+ local_irq_enable();
+ } else {
+ /*
+ * Give the HV an opportunity at the processor, since we are
+ * not doing any work.
+ */
+ poll_pending();
+ }
+}
+
+static int pseries_dedicated_idle(void)
{
long oldval;
- struct paca_struct *lpaca = get_paca(), *ppaca;
+ struct paca_struct *lpaca = get_paca();
+ unsigned int cpu = smp_processor_id();
unsigned long start_snooze;
unsigned long *smt_snooze_delay = &__get_cpu_var(smt_snooze_delay);
- unsigned int cpu = smp_processor_id();
-
- ppaca = &paca[cpu ^ 1];
while (1) {
/*
@@ -458,9 +490,13 @@ int dedicated_idle(void)
oldval = test_and_clear_thread_flag(TIF_NEED_RESCHED);
if (!oldval) {
set_thread_flag(TIF_POLLING_NRFLAG);
+
start_snooze = __get_tb() +
*smt_snooze_delay * tb_ticks_per_usec;
+
while (!need_resched() && !cpu_is_offline(cpu)) {
+ ppc64_runlatch_off();
+
/*
* Go into low thread priority and possibly
* low power mode.
@@ -468,60 +504,31 @@ int dedicated_idle(void)
HMT_low();
HMT_very_low();
- if (*smt_snooze_delay == 0 ||
- __get_tb() < start_snooze)
- continue;
-
- HMT_medium();
-
- if (!(ppaca->lppaca.idle)) {
- local_irq_disable();
-
- /*
- * We are about to sleep the thread
- * and so wont be polling any
- * more.
- */
- clear_thread_flag(TIF_POLLING_NRFLAG);
-
- /*
- * SMT dynamic mode. Cede will result
- * in this thread going dormant, if the
- * partner thread is still doing work.
- * Thread wakes up if partner goes idle,
- * an interrupt is presented, or a prod
- * occurs. Returning from the cede
- * enables external interrupts.
- */
- if (!need_resched())
- cede_processor();
- else
- local_irq_enable();
- } else {
- /*
- * Give the HV an opportunity at the
- * processor, since we are not doing
- * any work.
- */
- poll_pending();
+ if (*smt_snooze_delay != 0 &&
+ __get_tb() > start_snooze) {
+ HMT_medium();
+ dedicated_idle_sleep(cpu);
}
+
}
+ HMT_medium();
clear_thread_flag(TIF_POLLING_NRFLAG);
} else {
set_need_resched();
}
- HMT_medium();
lpaca->lppaca.idle = 0;
+ ppc64_runlatch_on();
+
schedule();
+
if (cpu_is_offline(cpu) && system_state == SYSTEM_RUNNING)
cpu_die();
}
- return 0;
}
-static int shared_idle(void)
+static int pseries_shared_idle(void)
{
struct paca_struct *lpaca = get_paca();
unsigned int cpu = smp_processor_id();
@@ -535,6 +542,7 @@ static int shared_idle(void)
while (!need_resched() && !cpu_is_offline(cpu)) {
local_irq_disable();
+ ppc64_runlatch_off();
/*
* Yield the processor to the hypervisor. We return if
@@ -550,13 +558,16 @@ static int shared_idle(void)
cede_processor();
else
local_irq_enable();
+
+ HMT_medium();
}
- HMT_medium();
lpaca->lppaca.idle = 0;
+ ppc64_runlatch_on();
+
schedule();
- if (cpu_is_offline(smp_processor_id()) &&
- system_state == SYSTEM_RUNNING)
+
+ if (cpu_is_offline(cpu) && system_state == SYSTEM_RUNNING)
cpu_die();
}