* smp swsusp [was Re: 2.6.12-rc2-mm2]
[not found] ` <1113149198.1076.2.camel@localhost.localdomain>
@ 2005-04-10 18:14 ` Pavel Machek
0 siblings, 0 replies; 2+ messages in thread
From: Pavel Machek @ 2005-04-10 18:14 UTC (permalink / raw)
To: Alexander Nyberg, kernel list
Hi!
> > Hi! The patch is ok, but this should be rewriten to use cpu hotplug instead.
> > I have some patches but they need more testing. --p
> >
>
> Heh yeah on the whole it didn't work too well ;), tell me if you need
> smp testing. I only have S{0,1,4,5} here though (shouldn't there be a S2
> at least also?), dual x64.
S2 basically does not exist. S3 is way more usable...
Here's patch, its against -mm; you'll probably need to adjust it a
bit. Maybe pci.c changes are no longer relevant.
Pavel
--- clean-mm/drivers/pci/pci.c 2005-03-21 11:39:32.000000000 +0100
+++ linux-mm/drivers/pci/pci.c 2005-03-22 01:41:48.000000000 +0100
@@ -376,11 +376,13 @@
if (!pci_find_capability(dev, PCI_CAP_ID_PM))
return PCI_D0;
+#if 0
if (platform_pci_choose_state) {
ret = platform_pci_choose_state(dev, state);
if (ret >= 0)
state = ret;
}
+#endif
switch (state) {
case 0: return PCI_D0;
case 3: return PCI_D3hot;
--- clean-mm/kernel/power/Kconfig 2005-01-22 21:24:53.000000000 +0100
+++ linux-mm/kernel/power/Kconfig 2005-03-23 11:40:14.000000000 +0100
@@ -28,7 +28,7 @@
config SOFTWARE_SUSPEND
bool "Software Suspend (EXPERIMENTAL)"
- depends on EXPERIMENTAL && PM && SWAP
+ depends on EXPERIMENTAL && PM && SWAP && (HOTPLUG_CPU || !SMP)
---help---
Enable the possibility of suspending the machine.
It doesn't need APM.
--- clean-mm/kernel/power/smp.c 2005-03-19 00:32:32.000000000 +0100
+++ linux-mm/kernel/power/smp.c 2005-03-23 15:38:30.000000000 +0100
@@ -7,79 +7,53 @@
* This file is released under the GPLv2.
*/
-#undef DEBUG
-
#include <linux/smp_lock.h>
#include <linux/interrupt.h>
#include <linux/suspend.h>
#include <linux/module.h>
#include <asm/atomic.h>
#include <asm/tlbflush.h>
+#include <asm/cpu.h>
-static atomic_t cpu_counter, freeze;
-
-
-static void smp_pause(void * data)
-{
- struct saved_context ctxt;
- __save_processor_state(&ctxt);
- printk("Sleeping in:\n");
- dump_stack();
- atomic_inc(&cpu_counter);
- while (atomic_read(&freeze)) {
- /* FIXME: restore takes place at random piece inside this.
- This should probably be written in assembly, and
- preserve general-purpose registers, too
-
- What about stack? We may need to move to new stack here.
-
- This should better be ran with interrupts disabled.
- */
- cpu_relax();
- barrier();
- }
- atomic_dec(&cpu_counter);
- __restore_processor_state(&ctxt);
-}
-
-static cpumask_t oldmask;
+cpumask_t frozen_cpus;
void disable_nonboot_cpus(void)
{
- printk("Freezing CPUs (at %d)", smp_processor_id());
- oldmask = current->cpus_allowed;
- set_cpus_allowed(current, cpumask_of_cpu(0));
- current->state = TASK_INTERRUPTIBLE;
- schedule_timeout(HZ);
- printk("...");
- BUG_ON(smp_processor_id() != 0);
-
- /* FIXME: for this to work, all the CPUs must be running
- * "idle" thread (or we deadlock). Is that guaranteed? */
+ int cpu, error;
- atomic_set(&cpu_counter, 0);
- atomic_set(&freeze, 1);
- smp_call_function(smp_pause, NULL, 0, 0);
- while (atomic_read(&cpu_counter) < (num_online_cpus() - 1)) {
- cpu_relax();
- barrier();
+ error = 0;
+ cpus_clear(frozen_cpus);
+ printk("Freezing cpus ...\n");
+ for_each_online_cpu(cpu) {
+ if (cpu == 0)
+ continue;
+ error = cpu_down(cpu);
+ if (!error) {
+ cpu_set(cpu, frozen_cpus);
+ printk("CPU%d is down\n", cpu);
+ continue;
+ }
+ printk("Error taking cpu %d down: %d\n", cpu, error);
}
- printk("ok\n");
+ BUG_ON(smp_processor_id() != 0);
+ if (error)
+ panic("cpus not sleeping");
}
void enable_nonboot_cpus(void)
{
- printk("Restarting CPUs");
- atomic_set(&freeze, 0);
- while (atomic_read(&cpu_counter)) {
- cpu_relax();
- barrier();
- }
- printk("...");
- set_cpus_allowed(current, oldmask);
- schedule();
- printk("ok\n");
+ int cpu, error;
+ printk("Thawing cpus ...\n");
+ for_each_cpu_mask(cpu, frozen_cpus) {
+ if (cpu == 0)
+ continue;
+ error = cpu_up(cpu);
+ if (!error) {
+ printk("CPU%d is up\n", cpu);
+ continue;
+ }
+ printk("Error taking cpu %d up: %d\n", cpu, error);
+ panic("Not enough cpus");
+ }
}
-
-
--- clean-mm/kernel/power/swsusp.c 2005-03-21 11:39:33.000000000 +0100
+++ linux-mm/kernel/power/swsusp.c 2005-03-23 15:34:53.000000000 +0100
@@ -1194,8 +1194,11 @@
return "version";
if (strcmp(swsusp_info.uts.machine,system_utsname.machine))
return "machine";
+#if 0
+ /* We can't use number of CPUs when we use hotplug to remove them ;-))) */
if(swsusp_info.cpus != num_online_cpus())
return "number of cpus";
+#endif
return NULL;
}
--
Boycott Kodak -- for their patent abuse against Java.
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