lkml.org 
[lkml]   [2012]   [Jan]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v2 1/4] PM/Freezer: Use thaw_kernel_threads() in preparation for changes to thaw_processes()
Date
As of now, thaw_processes() is a superset of thaw_kernel_threads() in the
sense that thaw_processes() thaws both userspace tasks and kernel threads.
But that is going to change very soon. So, in preparation for that, add
some calls to thaw_kernel_threads() like this:

* If only kernel threads need to be thawed, _replace_ thaw_processes()
with thaw_kernel_threads().

* If everything needs to be thawed, _add_ a call to thaw_kernel_threads()
adjacent to the existing call to thaw_processes().

Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
---

kernel/power/hibernate.c | 5 +++++
kernel/power/power.h | 15 +++++++++++++--
kernel/power/process.c | 4 ++--
kernel/power/user.c | 8 ++++++++
4 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index a5d4cf0..1670387 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -656,6 +656,11 @@ int hibernate(void)
}

Thaw:
+ /*
+ * Kernel threads had been frozen inside hibernation_snapshot().
+ * So thaw them here, on the success path.
+ */
+ thaw_kernel_threads();
thaw_processes();
Finish:
free_basic_memory_bitmaps();
diff --git a/kernel/power/power.h b/kernel/power/power.h
index 0c4defe..e37a1e0 100644
--- a/kernel/power/power.h
+++ b/kernel/power/power.h
@@ -231,12 +231,23 @@ extern int pm_test_level;
#ifdef CONFIG_SUSPEND_FREEZER
static inline int suspend_freeze_processes(void)
{
- int error = freeze_processes();
- return error ? : freeze_kernel_threads();
+ int error;
+
+ error = freeze_processes();
+ if (error)
+ goto Finish;
+
+ error = freeze_kernel_threads();
+ if (error)
+ thaw_processes();
+
+Finish:
+ return error;
}

static inline void suspend_thaw_processes(void)
{
+ thaw_kernel_threads();
thaw_processes();
}
#else
diff --git a/kernel/power/process.c b/kernel/power/process.c
index eeca003..3734fb9 100644
--- a/kernel/power/process.c
+++ b/kernel/power/process.c
@@ -143,7 +143,7 @@ int freeze_processes(void)
/**
* freeze_kernel_threads - Make freezable kernel threads go to the refrigerator.
*
- * On success, returns 0. On failure, -errno and system is fully thawed.
+ * On success, returns 0. On failure, -errno and all kernel threads are thawed.
*/
int freeze_kernel_threads(void)
{
@@ -159,7 +159,7 @@ int freeze_kernel_threads(void)
BUG_ON(in_atomic());

if (error)
- thaw_processes();
+ thaw_kernel_threads();
return error;
}

diff --git a/kernel/power/user.c b/kernel/power/user.c
index 3e10007..eaf5c97 100644
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -119,6 +119,7 @@ static int snapshot_release(struct inode *inode, struct file *filp)
free_all_swap_pages(data->swap);
if (data->frozen) {
pm_restore_gfp_mask();
+ thaw_kernel_threads();
thaw_processes();
}
pm_notifier_call_chain(data->mode == O_RDONLY ?
@@ -237,6 +238,13 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd,
if (!data->frozen || data->ready)
break;
pm_restore_gfp_mask();
+
+ /*
+ * Be paranoid and thaw kernel threads as well, in order to
+ * make sure that the system gets thawed fully, irrespective
+ * of which (error) path we took to come here.
+ */
+ thaw_kernel_threads();
thaw_processes();
usermodehelper_enable();
data->frozen = 0;


\
 
 \ /
  Last update: 2012-01-31 00:17    [W:0.052 / U:2.744 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site