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authorRobert Jennings <rcj@linux.vnet.ibm.com>2013-05-07 08:34:11 +0400
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2013-05-14 08:36:29 +0400
commit120496ac2d2d60aee68d3123a68169502a85f4b5 (patch)
treec0f3fcebb7cf53ffcbfb2dd7032c7a03c7fd5f23 /arch/powerpc/platforms/pseries/suspend.c
parenta94a14720eaf55c5f06d6ca7ecbe3f87f6864fc6 (diff)
downloadlinux-120496ac2d2d60aee68d3123a68169502a85f4b5.tar.xz
powerpc: Bring all threads online prior to migration/hibernation
This patch brings online all threads which are present but not online prior to migration/hibernation. After migration/hibernation those threads are taken back offline. During migration/hibernation all online CPUs must call H_JOIN, this is required by the hypervisor. Without this patch, threads that are offline (H_CEDE'd) will not be woken to make the H_JOIN call and the OS will be deadlocked (all threads either JOIN'd or CEDE'd). Cc: <stable@kernel.org> Signed-off-by: Robert Jennings <rcj@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/platforms/pseries/suspend.c')
-rw-r--r--arch/powerpc/platforms/pseries/suspend.c22
1 files changed, 22 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/pseries/suspend.c b/arch/powerpc/platforms/pseries/suspend.c
index 47226e04126d..5f997e79d570 100644
--- a/arch/powerpc/platforms/pseries/suspend.c
+++ b/arch/powerpc/platforms/pseries/suspend.c
@@ -16,6 +16,7 @@
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
+#include <linux/cpu.h>
#include <linux/delay.h>
#include <linux/suspend.h>
#include <linux/stat.h>
@@ -126,11 +127,15 @@ static ssize_t store_hibernate(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
+ cpumask_var_t offline_mask;
int rc;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
+ if (!alloc_cpumask_var(&offline_mask, GFP_TEMPORARY))
+ return -ENOMEM;
+
stream_id = simple_strtoul(buf, NULL, 16);
do {
@@ -140,15 +145,32 @@ static ssize_t store_hibernate(struct device *dev,
} while (rc == -EAGAIN);
if (!rc) {
+ /* All present CPUs must be online */
+ cpumask_andnot(offline_mask, cpu_present_mask,
+ cpu_online_mask);
+ rc = rtas_online_cpus_mask(offline_mask);
+ if (rc) {
+ pr_err("%s: Could not bring present CPUs online.\n",
+ __func__);
+ goto out;
+ }
+
stop_topology_update();
rc = pm_suspend(PM_SUSPEND_MEM);
start_topology_update();
+
+ /* Take down CPUs not online prior to suspend */
+ if (!rtas_offline_cpus_mask(offline_mask))
+ pr_warn("%s: Could not restore CPUs to offline "
+ "state.\n", __func__);
}
stream_id = 0;
if (!rc)
rc = count;
+out:
+ free_cpumask_var(offline_mask);
return rc;
}