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[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>
This commit is contained in:
Anton Blanchard 2005-07-07 17:56:33 -07:00 committed by Linus Torvalds
parent 3c57bb9f45
commit 050a09389e
1 changed files with 62 additions and 51 deletions
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115
arch/ppc64/kernel/pSeries_setup.c
View File

@ -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;
if (*smt_snooze_delay != 0 &&
__get_tb() > start_snooze) {
HMT_medium();
dedicated_idle_sleep(cpu);
}
}
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();
}
}
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();
}
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();
}