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[PATCH] Disable CPU hotplug during suspend

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The current suspend code has to be run on one CPU, so we use the CPU
hotplug to take the non-boot CPUs offline on SMP machines.  However, we
should also make sure that these CPUs will not be enabled by someone else
after we have disabled them.

The functions disable_nonboot_cpus() and enable_nonboot_cpus() are moved to
kernel/cpu.c, because they now refer to some stuff in there that should
better be static.  Also it's better if disable_nonboot_cpus() returns an
error instead of panicking if something goes wrong, and
enable_nonboot_cpus() has no reason to panic(), because the CPUs may have
been enabled by the userland before it tries to take them online.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Rafael J. Wysocki
2006-09-25 23:32:48 -07:00
committed by Linus Torvalds
parent e8eff5ac29
commit e3920fb42c
8 changed files with 146 additions and 105 deletions
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10
kernel/power/main.c
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@@ -16,6 +16,7 @@
#include <linux/init.h>
#include <linux/pm.h>
#include <linux/console.h>
#include <linux/cpu.h>
#include "power.h"
@@ -51,7 +52,7 @@ void pm_set_ops(struct pm_ops * ops)
static int suspend_prepare(suspend_state_t state)
{
int error = 0;
int error;
unsigned int free_pages;
if (!pm_ops || !pm_ops->enter)
@@ -59,12 +60,9 @@ static int suspend_prepare(suspend_state_t state)
pm_prepare_console();
disable_nonboot_cpus();
if (num_online_cpus() != 1) {
error = -EPERM;
error = disable_nonboot_cpus();
if (error)
goto Enable_cpu;
}
if (freeze_processes()) {
error = -EAGAIN;