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authorColin Cross <ccross@android.com>2013-05-06 23:50:14 +0000
committerArve Hjønnevåg <arve@android.com>2013-07-01 15:44:16 -0700
commitf8323ee4863cbe1a65f5da98f4c1d04b63d31c90 (patch)
tree1c3f126b5771f82118b7c630f7d9444b2978d6fe
parent68fdb041978defd40177c4a33adf365888ce0577 (diff)
downloadvexpress-lsk-f8323ee4863cbe1a65f5da98f4c1d04b63d31c90.tar.gz
freezer: add new freezable helpers using freezer_do_not_count()
Freezing tasks will wake up almost every userspace task from where it is blocking and force it to run until it hits a call to try_to_sleep(), generally on the exit path from the syscall it is blocking in. On resume each task will run again, usually restarting the syscall and running until it hits the same blocking call as it was originally blocked in. To allow tasks to avoid running on every suspend/resume cycle, this patch adds additional freezable wrappers around blocking calls that call freezer_do_not_count(). Combined with the previous patch, these tasks will not run during suspend or resume unless they wake up for another reason, in which case they will run until they hit the try_to_freeze() in freezer_count(), and then continue processing the wakeup after tasks are thawed. Additional patches will convert the most common locations that userspace blocks in to use freezable helpers. Change-Id: Id909760ce460f2532801a4b00d344f0816bfefc9 Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Colin Cross <ccross@android.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
-rw-r--r--include/linux/freezer.h61
1 files changed, 61 insertions, 0 deletions
diff --git a/include/linux/freezer.h b/include/linux/freezer.h
index 8430d4c51ec..7fd81b8c489 100644
--- a/include/linux/freezer.h
+++ b/include/linux/freezer.h
@@ -180,6 +180,32 @@ static inline void freezable_schedule_unsafe(void)
freezer_count_unsafe();
}
+/*
+ * Like freezable_schedule_timeout(), but should not block the freezer. Do not
+ * call this with locks held.
+ */
+static inline long freezable_schedule_timeout(long timeout)
+{
+ long __retval;
+ freezer_do_not_count();
+ __retval = schedule_timeout(timeout);
+ freezer_count();
+ return __retval;
+}
+
+/*
+ * Like schedule_timeout_interruptible(), but should not block the freezer. Do not
+ * call this with locks held.
+ */
+static inline long freezable_schedule_timeout_interruptible(long timeout)
+{
+ long __retval;
+ freezer_do_not_count();
+ __retval = schedule_timeout_interruptible(timeout);
+ freezer_count();
+ return __retval;
+}
+
/* Like schedule_timeout_killable(), but should not block the freezer. */
static inline long freezable_schedule_timeout_killable(long timeout)
{
@@ -201,6 +227,20 @@ static inline long freezable_schedule_timeout_killable_unsafe(long timeout)
}
/*
+ * Like schedule_hrtimeout_range(), but should not block the freezer. Do not
+ * call this with locks held.
+ */
+static inline int freezable_schedule_hrtimeout_range(ktime_t *expires,
+ unsigned long delta, const enum hrtimer_mode mode)
+{
+ int __retval;
+ freezer_do_not_count();
+ __retval = schedule_hrtimeout_range(expires, delta, mode);
+ freezer_count();
+ return __retval;
+}
+
+/*
* Freezer-friendly wrappers around wait_event_interruptible(),
* wait_event_killable() and wait_event_interruptible_timeout(), originally
* defined in <linux/wait.h>
@@ -244,6 +284,16 @@ static inline long freezable_schedule_timeout_killable_unsafe(long timeout)
__retval; \
})
+#define wait_event_freezable_exclusive(wq, condition) \
+({ \
+ int __retval; \
+ freezer_do_not_count(); \
+ __retval = wait_event_interruptible_exclusive(wq, condition); \
+ freezer_count(); \
+ __retval; \
+})
+
+
#else /* !CONFIG_FREEZER */
static inline bool frozen(struct task_struct *p) { return false; }
static inline bool freezing(struct task_struct *p) { return false; }
@@ -267,18 +317,29 @@ static inline void set_freezable(void) {}
#define freezable_schedule_unsafe() schedule()
+#define freezable_schedule_timeout(timeout) schedule_timeout(timeout)
+
+#define freezable_schedule_timeout_interruptible(timeout) \
+ schedule_timeout_interruptible(timeout)
+
#define freezable_schedule_timeout_killable(timeout) \
schedule_timeout_killable(timeout)
#define freezable_schedule_timeout_killable_unsafe(timeout) \
schedule_timeout_killable(timeout)
+#define freezable_schedule_hrtimeout_range(expires, delta, mode) \
+ schedule_hrtimeout_range(expires, delta, mode)
+
#define wait_event_freezable(wq, condition) \
wait_event_interruptible(wq, condition)
#define wait_event_freezable_timeout(wq, condition, timeout) \
wait_event_interruptible_timeout(wq, condition, timeout)
+#define wait_event_freezable_exclusive(wq, condition) \
+ wait_event_interruptible_exclusive(wq, condition)
+
#define wait_event_freezekillable(wq, condition) \
wait_event_killable(wq, condition)