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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/user.c
parente8eff5ac294e12531c4195e0c15a222d3c9015e5 (diff)
downloadlinux-e3920fb42c8ddfe63befb54d95c0e13eabacea9b.tar.bz2
[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/user.c')
-rw-r--r--kernel/power/user.c14
1 files changed, 9 insertions, 5 deletions
diff --git a/kernel/power/user.c b/kernel/power/user.c
index 3f1539fbe48a..0ef5e4ba39e5 100644
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -19,6 +19,7 @@
#include <linux/swapops.h>
#include <linux/pm.h>
#include <linux/fs.h>
+#include <linux/cpu.h>
#include <asm/uaccess.h>
@@ -139,12 +140,15 @@ static int snapshot_ioctl(struct inode *inode, struct file *filp,
if (data->frozen)
break;
down(&pm_sem);
- disable_nonboot_cpus();
- if (freeze_processes()) {
- thaw_processes();
- enable_nonboot_cpus();
- error = -EBUSY;
+ error = disable_nonboot_cpus();
+ if (!error) {
+ error = freeze_processes();
+ if (error) {
+ thaw_processes();
+ error = -EBUSY;
+ }
}
+ enable_nonboot_cpus();
up(&pm_sem);
if (!error)
data->frozen = 1;