From: Nigel Cunningham <ncunningham@cyclades.com>
To: Andrew Morton <akpm@osdl.org>, Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Nick's preempt nosched patch.
Date: Tue, 06 Dec 2005 15:02:52 +1000 [thread overview]
Message-ID: <1133844903.5501.17.camel@localhost> (raw)
Hi.
A while ago I had a problem with cpu hotplug failing to take down cpus
due to preemption problems. Nick prepared a patch (included below) that
fixed this, but it's not yet in mainline. The problem seems to have
disappeared on my work desktop (so I thought it had been applied until I
did a quick check), but a suspend2 user has just reported the problem
again. Can look at applying this or something better in mainline,
please?
Regards,
Nigel
arch/arm/kernel/process.c | 4 ++--
arch/arm/kernel/smp.c | 5 ++++-
arch/arm26/kernel/process.c | 12 +++++-------
arch/cris/arch-v32/kernel/smp.c | 2 ++
arch/cris/kernel/process.c | 2 ++
arch/frv/kernel/process.c | 6 +++++-
arch/h8300/kernel/process.c | 28 +++++++++++++++-------------
arch/i386/kernel/process.c | 4 +++-
arch/i386/kernel/smpboot.c | 2 ++
arch/ia64/kernel/process.c | 2 ++
arch/ia64/kernel/smpboot.c | 2 ++
arch/m32r/kernel/process.c | 2 ++
arch/m32r/kernel/smpboot.c | 1 +
arch/m68k/kernel/process.c | 2 ++
arch/mips/kernel/process.c | 2 ++
arch/mips/kernel/smp.c | 6 +++++-
arch/parisc/kernel/process.c | 2 ++
arch/parisc/kernel/smp.c | 2 ++
arch/ppc/kernel/idle.c | 15 ++++++++++-----
arch/ppc/kernel/smp.c | 2 ++
arch/ppc64/kernel/iSeries_setup.c | 4 ++++
arch/ppc64/kernel/idle.c | 4 ++++
arch/ppc64/kernel/pSeries_setup.c | 4 ++++
arch/ppc64/kernel/smp.c | 5 ++++-
arch/s390/kernel/process.c | 11 ++++++++---
arch/s390/kernel/smp.c | 2 ++
arch/sh/kernel/process.c | 2 ++
arch/sh/kernel/smp.c | 6 +++++-
arch/sh64/kernel/process.c | 2 ++
arch/sparc/kernel/process.c | 4 ++++
arch/sparc64/kernel/process.c | 4 ++++
arch/sparc64/kernel/smp.c | 3 +++
arch/v850/kernel/process.c | 16 ++++++++++------
arch/x86_64/kernel/process.c | 2 ++
arch/x86_64/kernel/smpboot.c | 1 +
arch/xtensa/kernel/process.c | 3 ++-
init/main.c | 4 +++-
37 files changed, 136 insertions(+), 44 deletions(-)
diff -ruNp 9210-sched-no-preempt-idle.patch-old/arch/arm/kernel/process.c 9210-sched-no-preempt-idle.patch-new/arch/arm/kernel/process.c
--- 9210-sched-no-preempt-idle.patch-old/arch/arm/kernel/process.c 2005-11-11 13:11:53.000000000 +1000
+++ 9210-sched-no-preempt-idle.patch-new/arch/arm/kernel/process.c 2005-12-06 14:49:24.000000000 +1000
@@ -107,13 +107,13 @@ void cpu_idle(void)
void (*idle)(void) = pm_idle;
if (!idle)
idle = default_idle;
- preempt_disable();
leds_event(led_idle_start);
while (!need_resched())
idle();
leds_event(led_idle_end);
- preempt_enable();
+ preempt_enable_no_resched();
schedule();
+ preempt_disable();
}
}
diff -ruNp 9210-sched-no-preempt-idle.patch-old/arch/arm/kernel/smp.c 9210-sched-no-preempt-idle.patch-new/arch/arm/kernel/smp.c
--- 9210-sched-no-preempt-idle.patch-old/arch/arm/kernel/smp.c 2005-11-11 13:11:53.000000000 +1000
+++ 9210-sched-no-preempt-idle.patch-new/arch/arm/kernel/smp.c 2005-12-06 14:49:24.000000000 +1000
@@ -162,7 +162,10 @@ int __cpuinit __cpu_up(unsigned int cpu)
asmlinkage void __cpuinit secondary_start_kernel(void)
{
struct mm_struct *mm = &init_mm;
- unsigned int cpu = smp_processor_id();
+ unsigned int cpu;
+
+ preempt_disable();
+ cpu = smp_processor_id();
printk("CPU%u: Booted secondary processor\n", cpu);
diff -ruNp 9210-sched-no-preempt-idle.patch-old/arch/arm26/kernel/process.c 9210-sched-no-preempt-idle.patch-new/arch/arm26/kernel/process.c
--- 9210-sched-no-preempt-idle.patch-old/arch/arm26/kernel/process.c 2005-11-11 13:11:56.000000000 +1000
+++ 9210-sched-no-preempt-idle.patch-new/arch/arm26/kernel/process.c 2005-12-06 14:49:24.000000000 +1000
@@ -74,15 +74,13 @@ __setup("hlt", hlt_setup);
void cpu_idle(void)
{
/* endless idle loop with no priority at all */
- preempt_disable();
while (1) {
- while (!need_resched()) {
- local_irq_disable();
- if (!need_resched() && !hlt_counter)
- local_irq_enable();
- }
+ while (!need_resched())
+ cpu_relax();
+ preempt_enable_no_resched();
+ schedule();
+ preempt_disable();
}
- schedule();
}
static char reboot_mode = 'h';
diff -ruNp 9210-sched-no-preempt-idle.patch-old/arch/cris/arch-v32/kernel/smp.c 9210-sched-no-preempt-idle.patch-new/arch/cris/arch-v32/kernel/smp.c
--- 9210-sched-no-preempt-idle.patch-old/arch/cris/arch-v32/kernel/smp.c 2005-11-11 13:11:57.000000000 +1000
+++ 9210-sched-no-preempt-idle.patch-new/arch/cris/arch-v32/kernel/smp.c 2005-12-06 14:49:24.000000000 +1000
@@ -146,6 +146,8 @@ void __init smp_callin(void)
int cpu = cpu_now_booting;
reg_intr_vect_rw_mask vect_mask = {0};
+ preempt_disable();
+
/* Initialise the idle task for this CPU */
atomic_inc(&init_mm.mm_count);
current->active_mm = &init_mm;
diff -ruNp 9210-sched-no-preempt-idle.patch-old/arch/cris/kernel/process.c 9210-sched-no-preempt-idle.patch-new/arch/cris/kernel/process.c
--- 9210-sched-no-preempt-idle.patch-old/arch/cris/kernel/process.c 2005-11-11 13:11:57.000000000 +1000
+++ 9210-sched-no-preempt-idle.patch-new/arch/cris/kernel/process.c 2005-12-06 14:49:24.000000000 +1000
@@ -218,7 +218,9 @@ void cpu_idle (void)
idle = default_idle;
idle();
}
+ preempt_enable_no_resched();
schedule();
+ preempt_disable();
}
}
diff -ruNp 9210-sched-no-preempt-idle.patch-old/arch/frv/kernel/process.c 9210-sched-no-preempt-idle.patch-new/arch/frv/kernel/process.c
--- 9210-sched-no-preempt-idle.patch-old/arch/frv/kernel/process.c 2005-11-11 13:11:57.000000000 +1000
+++ 9210-sched-no-preempt-idle.patch-new/arch/frv/kernel/process.c 2005-12-06 14:49:24.000000000 +1000
@@ -77,16 +77,20 @@ void (*idle)(void) = core_sleep_idle;
*/
void cpu_idle(void)
{
+ int cpu = smp_processor_id();
+
/* endless idle loop with no priority at all */
while (1) {
while (!need_resched()) {
- irq_stat[smp_processor_id()].idle_timestamp = jiffies;
+ irq_stat[cpu].idle_timestamp = jiffies;
if (!frv_dma_inprogress && idle)
idle();
}
+ preempt_enable_no_resched();
schedule();
+ preempt_disable();
}
}
diff -ruNp 9210-sched-no-preempt-idle.patch-old/arch/h8300/kernel/process.c 9210-sched-no-preempt-idle.patch-new/arch/h8300/kernel/process.c
--- 9210-sched-no-preempt-idle.patch-old/arch/h8300/kernel/process.c 2005-11-11 13:11:57.000000000 +1000
+++ 9210-sched-no-preempt-idle.patch-new/arch/h8300/kernel/process.c 2005-12-06 14:49:24.000000000 +1000
@@ -53,22 +53,18 @@ asmlinkage void ret_from_fork(void);
#if !defined(CONFIG_H8300H_SIM) && !defined(CONFIG_H8S_SIM)
void default_idle(void)
{
- while(1) {
- if (!need_resched()) {
- local_irq_enable();
- __asm__("sleep");
- local_irq_disable();
- }
- schedule();
- }
+ local_irq_disable();
+ if (!need_resched()) {
+ local_irq_enable();
+ /* XXX: race here! What if need_resched() gets set now? */
+ __asm__("sleep");
+ } else
+ local_irq_enable();
}
#else
void default_idle(void)
{
- while(1) {
- if (need_resched())
- schedule();
- }
+ cpu_relax();
}
#endif
void (*idle)(void) = default_idle;
@@ -81,7 +77,13 @@ void (*idle)(void) = default_idle;
*/
void cpu_idle(void)
{
- idle();
+ while (1) {
+ while (!need_resched())
+ idle();
+ preempt_enable_no_resched();
+ schedule();
+ preempt_disable();
+ }
}
void machine_restart(char * __unused)
diff -ruNp 9210-sched-no-preempt-idle.patch-old/arch/i386/kernel/process.c 9210-sched-no-preempt-idle.patch-new/arch/i386/kernel/process.c
--- 9210-sched-no-preempt-idle.patch-old/arch/i386/kernel/process.c 2005-11-11 13:11:58.000000000 +1000
+++ 9210-sched-no-preempt-idle.patch-new/arch/i386/kernel/process.c 2005-12-06 14:49:24.000000000 +1000
@@ -179,7 +179,7 @@ static inline void play_dead(void)
*/
void cpu_idle(void)
{
- int cpu = raw_smp_processor_id();
+ int cpu = smp_processor_id();
/* endless idle loop with no priority at all */
while (1) {
@@ -201,7 +201,9 @@ void cpu_idle(void)
__get_cpu_var(irq_stat).idle_timestamp = jiffies;
idle();
}
+ preempt_enable_no_resched();
schedule();
+ preempt_disable();
}
}
diff -ruNp 9210-sched-no-preempt-idle.patch-old/arch/i386/kernel/smpboot.c 9210-sched-no-preempt-idle.patch-new/arch/i386/kernel/smpboot.c
--- 9210-sched-no-preempt-idle.patch-old/arch/i386/kernel/smpboot.c 2005-12-06 14:50:23.000000000 +1000
+++ 9210-sched-no-preempt-idle.patch-new/arch/i386/kernel/smpboot.c 2005-12-06 14:49:24.000000000 +1000
@@ -485,6 +485,8 @@ set_cpu_sibling_map(int cpu)
*/
static void __devinit start_secondary(void *unused)
{
+ preempt_disable();
+
/*
* Dont put anything before smp_callin(), SMP
* booting is too fragile that we want to limit the
diff -ruNp 9210-sched-no-preempt-idle.patch-old/arch/ia64/kernel/process.c 9210-sched-no-preempt-idle.patch-new/arch/ia64/kernel/process.c
--- 9210-sched-no-preempt-idle.patch-old/arch/ia64/kernel/process.c 2005-11-11 13:12:00.000000000 +1000
+++ 9210-sched-no-preempt-idle.patch-new/arch/ia64/kernel/process.c 2005-12-06 14:49:24.000000000 +1000
@@ -292,7 +292,9 @@ cpu_idle (void)
#ifdef CONFIG_SMP
normal_xtp();
#endif
+ preempt_enable_no_resched();
schedule();
+ preempt_disable();
check_pgt_cache();
if (cpu_is_offline(smp_processor_id()))
play_dead();
diff -ruNp 9210-sched-no-preempt-idle.patch-old/arch/ia64/kernel/smpboot.c 9210-sched-no-preempt-idle.patch-new/arch/ia64/kernel/smpboot.c
--- 9210-sched-no-preempt-idle.patch-old/arch/ia64/kernel/smpboot.c 2005-11-11 13:12:00.000000000 +1000
+++ 9210-sched-no-preempt-idle.patch-new/arch/ia64/kernel/smpboot.c 2005-12-06 14:49:24.000000000 +1000
@@ -394,6 +394,8 @@ smp_callin (void)
int __devinit
start_secondary (void *unused)
{
+ preempt_disable();
+
/* Early console may use I/O ports */
ia64_set_kr(IA64_KR_IO_BASE, __pa(ia64_iobase));
Dprintk("start_secondary: starting CPU 0x%x\n", hard_smp_processor_id());
diff -ruNp 9210-sched-no-preempt-idle.patch-old/arch/m32r/kernel/process.c 9210-sched-no-preempt-idle.patch-new/arch/m32r/kernel/process.c
--- 9210-sched-no-preempt-idle.patch-old/arch/m32r/kernel/process.c 2005-11-11 13:12:00.000000000 +1000
+++ 9210-sched-no-preempt-idle.patch-new/arch/m32r/kernel/process.c 2005-12-06 14:49:24.000000000 +1000
@@ -104,7 +104,9 @@ void cpu_idle (void)
idle();
}
+ preempt_enable_no_resched();
schedule();
+ preempt_disable();
}
}
diff -ruNp 9210-sched-no-preempt-idle.patch-old/arch/m32r/kernel/smpboot.c 9210-sched-no-preempt-idle.patch-new/arch/m32r/kernel/smpboot.c
--- 9210-sched-no-preempt-idle.patch-old/arch/m32r/kernel/smpboot.c 2005-11-11 13:12:01.000000000 +1000
+++ 9210-sched-no-preempt-idle.patch-new/arch/m32r/kernel/smpboot.c 2005-12-06 14:49:24.000000000 +1000
@@ -425,6 +425,7 @@ void __init smp_cpus_done(unsigned int m
*==========================================================================*/
int __init start_secondary(void *unused)
{
+ preempt_disable();
cpu_init();
smp_callin();
while (!cpu_isset(smp_processor_id(), smp_commenced_mask))
diff -ruNp 9210-sched-no-preempt-idle.patch-old/arch/m68k/kernel/process.c 9210-sched-no-preempt-idle.patch-new/arch/m68k/kernel/process.c
--- 9210-sched-no-preempt-idle.patch-old/arch/m68k/kernel/process.c 2005-11-11 13:12:01.000000000 +1000
+++ 9210-sched-no-preempt-idle.patch-new/arch/m68k/kernel/process.c 2005-12-06 14:49:24.000000000 +1000
@@ -102,7 +102,9 @@ void cpu_idle(void)
while (1) {
while (!need_resched())
idle();
+ preempt_enable_no_resched();
schedule();
+ preempt_disable();
}
}
diff -ruNp 9210-sched-no-preempt-idle.patch-old/arch/mips/kernel/process.c 9210-sched-no-preempt-idle.patch-new/arch/mips/kernel/process.c
--- 9210-sched-no-preempt-idle.patch-old/arch/mips/kernel/process.c 2005-11-11 13:12:03.000000000 +1000
+++ 9210-sched-no-preempt-idle.patch-new/arch/mips/kernel/process.c 2005-12-06 14:49:24.000000000 +1000
@@ -58,7 +58,9 @@ ATTRIB_NORET void cpu_idle(void)
while (!need_resched())
if (cpu_wait)
(*cpu_wait)();
+ preempt_enable_no_resched();
schedule();
+ preempt_disable()
}
}
diff -ruNp 9210-sched-no-preempt-idle.patch-old/arch/mips/kernel/smp.c 9210-sched-no-preempt-idle.patch-new/arch/mips/kernel/smp.c
--- 9210-sched-no-preempt-idle.patch-old/arch/mips/kernel/smp.c 2005-11-11 13:12:03.000000000 +1000
+++ 9210-sched-no-preempt-idle.patch-new/arch/mips/kernel/smp.c 2005-12-06 14:49:24.000000000 +1000
@@ -83,7 +83,11 @@ extern ATTRIB_NORET void cpu_idle(void);
*/
asmlinkage void start_secondary(void)
{
- unsigned int cpu = smp_processor_id();
+ unsigned int cpu;
+
+ preempt_disable();
+
+ cpu = smp_processor_id();
cpu_probe();
cpu_report();
diff -ruNp 9210-sched-no-preempt-idle.patch-old/arch/parisc/kernel/process.c 9210-sched-no-preempt-idle.patch-new/arch/parisc/kernel/process.c
--- 9210-sched-no-preempt-idle.patch-old/arch/parisc/kernel/process.c 2005-11-11 13:12:05.000000000 +1000
+++ 9210-sched-no-preempt-idle.patch-new/arch/parisc/kernel/process.c 2005-12-06 14:49:24.000000000 +1000
@@ -92,7 +92,9 @@ void cpu_idle(void)
while (1) {
while (!need_resched())
barrier();
+ preempt_enable_no_resched();
schedule();
+ preempt_disable();
check_pgt_cache();
}
}
diff -ruNp 9210-sched-no-preempt-idle.patch-old/arch/parisc/kernel/smp.c 9210-sched-no-preempt-idle.patch-new/arch/parisc/kernel/smp.c
--- 9210-sched-no-preempt-idle.patch-old/arch/parisc/kernel/smp.c 2005-11-11 13:12:05.000000000 +1000
+++ 9210-sched-no-preempt-idle.patch-new/arch/parisc/kernel/smp.c 2005-12-06 14:49:24.000000000 +1000
@@ -462,6 +462,8 @@ void __init smp_callin(void)
void *istack;
#endif
+ preempt_disable();
+
smp_cpu_init(slave_id);
#if 0 /* NOT WORKING YET - see entry.S */
diff -ruNp 9210-sched-no-preempt-idle.patch-old/arch/ppc/kernel/idle.c 9210-sched-no-preempt-idle.patch-new/arch/ppc/kernel/idle.c
--- 9210-sched-no-preempt-idle.patch-old/arch/ppc/kernel/idle.c 2005-11-11 13:12:06.000000000 +1000
+++ 9210-sched-no-preempt-idle.patch-new/arch/ppc/kernel/idle.c 2005-12-06 14:49:24.000000000 +1000
@@ -52,10 +52,6 @@ void default_idle(void)
}
#endif
}
- if (need_resched())
- schedule();
- if (cpu_is_offline(cpu) && system_state == SYSTEM_RUNNING)
- cpu_die();
}
/*
@@ -63,11 +59,20 @@ void default_idle(void)
*/
void cpu_idle(void)
{
- for (;;)
+ for (;;) {
if (ppc_md.idle != NULL)
ppc_md.idle();
else
default_idle();
+ if (cpu_is_offline(cpu) && system_state == SYSTEM_RUNNING)
+ cpu_die();
+ if (need_resched()) {
+ preempt_enable_no_resched();
+ schedule();
+ preempt_disable();
+ }
+
+ }
}
#if defined(CONFIG_SYSCTL) && defined(CONFIG_6xx)
diff -ruNp 9210-sched-no-preempt-idle.patch-old/arch/ppc/kernel/smp.c 9210-sched-no-preempt-idle.patch-new/arch/ppc/kernel/smp.c
--- 9210-sched-no-preempt-idle.patch-old/arch/ppc/kernel/smp.c 2005-11-11 13:12:06.000000000 +1000
+++ 9210-sched-no-preempt-idle.patch-new/arch/ppc/kernel/smp.c 2005-12-06 14:49:24.000000000 +1000
@@ -339,6 +339,8 @@ int __devinit start_secondary(void *unus
{
int cpu;
+ preempt_disable();
+
atomic_inc(&init_mm.mm_count);
current->active_mm = &init_mm;
diff -ruNp 9210-sched-no-preempt-idle.patch-old/arch/ppc64/kernel/idle.c 9210-sched-no-preempt-idle.patch-new/arch/ppc64/kernel/idle.c
--- 9210-sched-no-preempt-idle.patch-old/arch/ppc64/kernel/idle.c 2005-11-11 13:12:08.000000000 +1000
+++ 9210-sched-no-preempt-idle.patch-new/arch/ppc64/kernel/idle.c 2005-12-06 14:49:24.000000000 +1000
@@ -60,7 +60,9 @@ int default_idle(void)
}
ppc64_runlatch_on();
+ preempt_enable_no_resched();
schedule();
+ preempt_disable();
if (cpu_is_offline(cpu) && system_state == SYSTEM_RUNNING)
cpu_die();
}
@@ -78,7 +80,9 @@ int native_idle(void)
if (need_resched()) {
ppc64_runlatch_on();
+ preempt_enable_no_resched();
schedule();
+ preempt_disable();
}
if (cpu_is_offline(smp_processor_id()) &&
diff -ruNp 9210-sched-no-preempt-idle.patch-old/arch/ppc64/kernel/iSeries_setup.c 9210-sched-no-preempt-idle.patch-new/arch/ppc64/kernel/iSeries_setup.c
--- 9210-sched-no-preempt-idle.patch-old/arch/ppc64/kernel/iSeries_setup.c 2005-11-11 13:12:08.000000000 +1000
+++ 9210-sched-no-preempt-idle.patch-new/arch/ppc64/kernel/iSeries_setup.c 2005-12-06 14:49:24.000000000 +1000
@@ -898,7 +898,9 @@ static int iseries_shared_idle(void)
if (hvlpevent_is_pending())
process_iSeries_events();
+ preempt_enable_no_resched();
schedule();
+ preempt_disable();
}
return 0;
@@ -932,7 +934,9 @@ static int iseries_dedicated_idle(void)
}
ppc64_runlatch_on();
+ preempt_enable_no_resched();
schedule();
+ preempt_disable();
}
return 0;
diff -ruNp 9210-sched-no-preempt-idle.patch-old/arch/ppc64/kernel/pSeries_setup.c 9210-sched-no-preempt-idle.patch-new/arch/ppc64/kernel/pSeries_setup.c
--- 9210-sched-no-preempt-idle.patch-old/arch/ppc64/kernel/pSeries_setup.c 2005-11-11 13:12:08.000000000 +1000
+++ 9210-sched-no-preempt-idle.patch-new/arch/ppc64/kernel/pSeries_setup.c 2005-12-06 14:49:24.000000000 +1000
@@ -537,7 +537,9 @@ static int pseries_dedicated_idle(void)
lpaca->lppaca.idle = 0;
ppc64_runlatch_on();
+ preempt_enable_no_resched();
schedule();
+ preempt_disable();
if (cpu_is_offline(cpu) && system_state == SYSTEM_RUNNING)
cpu_die();
@@ -581,7 +583,9 @@ static int pseries_shared_idle(void)
lpaca->lppaca.idle = 0;
ppc64_runlatch_on();
+ preempt_enable_no_resched();
schedule();
+ preempt_disable();
if (cpu_is_offline(cpu) && system_state == SYSTEM_RUNNING)
cpu_die();
diff -ruNp 9210-sched-no-preempt-idle.patch-old/arch/ppc64/kernel/smp.c 9210-sched-no-preempt-idle.patch-new/arch/ppc64/kernel/smp.c
--- 9210-sched-no-preempt-idle.patch-old/arch/ppc64/kernel/smp.c 2005-11-11 13:12:08.000000000 +1000
+++ 9210-sched-no-preempt-idle.patch-new/arch/ppc64/kernel/smp.c 2005-12-06 14:49:24.000000000 +1000
@@ -545,7 +545,10 @@ int __devinit __cpu_up(unsigned int cpu)
/* Activate a secondary processor. */
int __devinit start_secondary(void *unused)
{
- unsigned int cpu = smp_processor_id();
+ unsigned int cpu;
+
+ preempt_disable();
+ cpu = smp_processor_id();
atomic_inc(&init_mm.mm_count);
current->active_mm = &init_mm;
diff -ruNp 9210-sched-no-preempt-idle.patch-old/arch/s390/kernel/process.c 9210-sched-no-preempt-idle.patch-new/arch/s390/kernel/process.c
--- 9210-sched-no-preempt-idle.patch-old/arch/s390/kernel/process.c 2005-11-11 13:12:10.000000000 +1000
+++ 9210-sched-no-preempt-idle.patch-new/arch/s390/kernel/process.c 2005-12-06 14:49:24.000000000 +1000
@@ -102,7 +102,6 @@ void default_idle(void)
local_irq_disable();
if (need_resched()) {
local_irq_enable();
- schedule();
return;
}
@@ -139,8 +138,14 @@ void default_idle(void)
void cpu_idle(void)
{
- for (;;)
- default_idle();
+ for (;;) {
+ while (!need_resched())
+ default_idle();
+
+ preempt_enable_no_resched();
+ schedule();
+ preempt_disable();
+ }
}
void show_regs(struct pt_regs *regs)
diff -ruNp 9210-sched-no-preempt-idle.patch-old/arch/s390/kernel/smp.c 9210-sched-no-preempt-idle.patch-new/arch/s390/kernel/smp.c
--- 9210-sched-no-preempt-idle.patch-old/arch/s390/kernel/smp.c 2005-11-11 13:12:10.000000000 +1000
+++ 9210-sched-no-preempt-idle.patch-new/arch/s390/kernel/smp.c 2005-12-06 14:49:24.000000000 +1000
@@ -531,6 +531,8 @@ extern void pfault_fini(void);
int __devinit start_secondary(void *cpuvoid)
{
+ preempt_disable();
+
/* Setup the cpu */
cpu_init();
/* init per CPU timer */
diff -ruNp 9210-sched-no-preempt-idle.patch-old/arch/sh/kernel/process.c 9210-sched-no-preempt-idle.patch-new/arch/sh/kernel/process.c
--- 9210-sched-no-preempt-idle.patch-old/arch/sh/kernel/process.c 2005-11-11 13:12:11.000000000 +1000
+++ 9210-sched-no-preempt-idle.patch-new/arch/sh/kernel/process.c 2005-12-06 14:49:24.000000000 +1000
@@ -64,7 +64,9 @@ void default_idle(void)
cpu_sleep();
}
+ preempt_enable_no_resched();
schedule();
+ preempt_disable();
}
}
diff -ruNp 9210-sched-no-preempt-idle.patch-old/arch/sh/kernel/smp.c 9210-sched-no-preempt-idle.patch-new/arch/sh/kernel/smp.c
--- 9210-sched-no-preempt-idle.patch-old/arch/sh/kernel/smp.c 2005-11-11 13:12:11.000000000 +1000
+++ 9210-sched-no-preempt-idle.patch-new/arch/sh/kernel/smp.c 2005-12-06 14:49:24.000000000 +1000
@@ -112,7 +112,11 @@ int __cpu_up(unsigned int cpu)
int start_secondary(void *unused)
{
- unsigned int cpu = smp_processor_id();
+ unsigned int cpu;
+
+ preempt_disable();
+
+ cpu = smp_processor_id();
atomic_inc(&init_mm.mm_count);
current->active_mm = &init_mm;
diff -ruNp 9210-sched-no-preempt-idle.patch-old/arch/sh64/kernel/process.c 9210-sched-no-preempt-idle.patch-new/arch/sh64/kernel/process.c
--- 9210-sched-no-preempt-idle.patch-old/arch/sh64/kernel/process.c 2005-11-11 13:12:11.000000000 +1000
+++ 9210-sched-no-preempt-idle.patch-new/arch/sh64/kernel/process.c 2005-12-06 14:49:24.000000000 +1000
@@ -334,7 +334,9 @@ void default_idle(void)
}
local_irq_enable();
}
+ preempt_enable_no_resched();
schedule();
+ preempt_disable();
}
}
diff -ruNp 9210-sched-no-preempt-idle.patch-old/arch/sparc/kernel/process.c 9210-sched-no-preempt-idle.patch-new/arch/sparc/kernel/process.c
--- 9210-sched-no-preempt-idle.patch-old/arch/sparc/kernel/process.c 2005-11-11 13:12:11.000000000 +1000
+++ 9210-sched-no-preempt-idle.patch-new/arch/sparc/kernel/process.c 2005-12-06 14:49:24.000000000 +1000
@@ -120,7 +120,9 @@ void cpu_idle(void)
(*pm_idle)();
}
+ preempt_enable_no_resched();
schedule();
+ preempt_disable();
check_pgt_cache();
}
}
@@ -133,7 +135,9 @@ void cpu_idle(void)
/* endless idle loop with no priority at all */
while(1) {
if(need_resched()) {
+ preempt_enable_no_resched();
schedule();
+ preempt_disable();
check_pgt_cache();
}
barrier(); /* or else gcc optimizes... */
diff -ruNp 9210-sched-no-preempt-idle.patch-old/arch/sparc64/kernel/process.c 9210-sched-no-preempt-idle.patch-new/arch/sparc64/kernel/process.c
--- 9210-sched-no-preempt-idle.patch-old/arch/sparc64/kernel/process.c 2005-11-11 13:12:12.000000000 +1000
+++ 9210-sched-no-preempt-idle.patch-new/arch/sparc64/kernel/process.c 2005-12-06 14:49:24.000000000 +1000
@@ -74,7 +74,9 @@ void cpu_idle(void)
while (!need_resched())
barrier();
+ preempt_enable_no_resched();
schedule();
+ preempt_disable();
check_pgt_cache();
}
}
@@ -93,7 +95,9 @@ void cpu_idle(void)
if (need_resched()) {
unidle_me();
clear_thread_flag(TIF_POLLING_NRFLAG);
+ preempt_enable_no_resched();
schedule();
+ preempt_disable();
set_thread_flag(TIF_POLLING_NRFLAG);
check_pgt_cache();
}
diff -ruNp 9210-sched-no-preempt-idle.patch-old/arch/sparc64/kernel/smp.c 9210-sched-no-preempt-idle.patch-new/arch/sparc64/kernel/smp.c
--- 9210-sched-no-preempt-idle.patch-old/arch/sparc64/kernel/smp.c 2005-11-11 13:12:12.000000000 +1000
+++ 9210-sched-no-preempt-idle.patch-new/arch/sparc64/kernel/smp.c 2005-12-06 14:49:24.000000000 +1000
@@ -168,6 +168,9 @@ void __init smp_callin(void)
rmb();
cpu_set(cpuid, cpu_online_map);
+
+ /* idle thread is expected to have preempt disabled */
+ preempt_disable();
}
void cpu_panic(void)
diff -ruNp 9210-sched-no-preempt-idle.patch-old/arch/v850/kernel/process.c 9210-sched-no-preempt-idle.patch-new/arch/v850/kernel/process.c
--- 9210-sched-no-preempt-idle.patch-old/arch/v850/kernel/process.c 2005-11-11 13:12:14.000000000 +1000
+++ 9210-sched-no-preempt-idle.patch-new/arch/v850/kernel/process.c 2005-12-06 14:49:24.000000000 +1000
@@ -36,11 +36,8 @@ extern void ret_from_fork (void);
/* The idle loop. */
void default_idle (void)
{
- while (1) {
- while (! need_resched ())
- asm ("halt; nop; nop; nop; nop; nop" ::: "cc");
- schedule ();
- }
+ while (! need_resched ())
+ asm ("halt; nop; nop; nop; nop; nop" ::: "cc");
}
void (*idle)(void) = default_idle;
@@ -54,7 +51,14 @@ void (*idle)(void) = default_idle;
void cpu_idle (void)
{
/* endless idle loop with no priority at all */
- (*idle) ();
+ while (1) {
+ while (!need_resched())
+ (*idle) ();
+
+ preempt_enable_no_resched();
+ schedule();
+ preempt_disable();
+ }
}
/*
diff -ruNp 9210-sched-no-preempt-idle.patch-old/arch/x86_64/kernel/process.c 9210-sched-no-preempt-idle.patch-new/arch/x86_64/kernel/process.c
--- 9210-sched-no-preempt-idle.patch-old/arch/x86_64/kernel/process.c 2005-11-11 13:12:15.000000000 +1000
+++ 9210-sched-no-preempt-idle.patch-new/arch/x86_64/kernel/process.c 2005-12-06 14:49:24.000000000 +1000
@@ -204,7 +204,9 @@ void cpu_idle (void)
idle();
}
+ preempt_enable_no_resched();
schedule();
+ preempt_disable();
}
}
diff -ruNp 9210-sched-no-preempt-idle.patch-old/arch/x86_64/kernel/smpboot.c 9210-sched-no-preempt-idle.patch-new/arch/x86_64/kernel/smpboot.c
--- 9210-sched-no-preempt-idle.patch-old/arch/x86_64/kernel/smpboot.c 2005-11-11 13:12:15.000000000 +1000
+++ 9210-sched-no-preempt-idle.patch-new/arch/x86_64/kernel/smpboot.c 2005-12-06 14:49:29.000000000 +1000
@@ -474,6 +474,7 @@ void __cpuinit start_secondary(void)
* things done here to the most necessary things.
*/
cpu_init();
+ preempt_disable();
smp_callin();
/* otherwise gcc will move up the smp_processor_id before the cpu_init */
diff -ruNp 9210-sched-no-preempt-idle.patch-old/arch/xtensa/kernel/process.c 9210-sched-no-preempt-idle.patch-new/arch/xtensa/kernel/process.c
--- 9210-sched-no-preempt-idle.patch-old/arch/xtensa/kernel/process.c 2005-11-11 13:12:15.000000000 +1000
+++ 9210-sched-no-preempt-idle.patch-new/arch/xtensa/kernel/process.c 2005-12-06 14:49:24.000000000 +1000
@@ -96,8 +96,9 @@ void cpu_idle(void)
while (1) {
while (!need_resched())
platform_idle();
- preempt_enable();
+ preempt_enable_no_resched();
schedule();
+ preempt_disable();
}
}
diff -ruNp 9210-sched-no-preempt-idle.patch-old/init/main.c 9210-sched-no-preempt-idle.patch-new/init/main.c
--- 9210-sched-no-preempt-idle.patch-old/init/main.c 2005-12-06 14:50:30.000000000 +1000
+++ 9210-sched-no-preempt-idle.patch-new/init/main.c 2005-12-06 14:49:24.000000000 +1000
@@ -418,14 +418,16 @@ static void noinline rest_init(void)
kernel_thread(init, NULL, CLONE_FS | CLONE_SIGHAND);
numa_default_policy();
unlock_kernel();
- preempt_enable_no_resched();
/*
* The boot idle thread must execute schedule()
* at least one to get things moving:
*/
+ preempt_enable_no_resched();
schedule();
+ preempt_disable();
+ /* Call into cpu_idle with preempt disabled */
cpu_idle();
}
next reply other threads:[~2005-12-06 5:06 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-12-06 5:02 Nigel Cunningham [this message]
2005-12-06 5:23 ` Nick's preempt nosched patch Nigel Cunningham
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