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authorRafael J. Wysocki <rjw@sisk.pl>2006-09-25 23:32:48 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-09-26 08:48:59 -0700
commite3920fb42c8ddfe63befb54d95c0e13eabacea9b (patch)
tree08371a71e58e6e9d3ec62dfa6a22b3b5e6ff0fd5 /kernel/power/main.c
parente8eff5ac294e12531c4195e0c15a222d3c9015e5 (diff)
[PATCH] Disable CPU hotplug during suspend
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>
Diffstat (limited to 'kernel/power/main.c')
-rw-r--r--kernel/power/main.c10
1 files changed, 4 insertions, 6 deletions
diff --git a/kernel/power/main.c b/kernel/power/main.c
index 6d295c77679..4d403323a7b 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -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;