Subject: [PATCH v7 15/22] freezer: Add frozen_or_skipped() helper function

From: Will Deacon <[email-masked]>
Date: Tue, 25 May 2021 16:14:25 +0100

Occasionally it is necessary to see if a task is either frozen or
sleeping in the PF_FREEZER_SKIP state. In preparation for adding
additional users of this check, introduce a frozen_or_skipped() helper
function and convert the hung task detector over to using it.

Signed-off-by: Will Deacon <[email-masked]>
---
 include/linux/freezer.h | 6 ++++++
 kernel/hung_task.c      | 4 ++--
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/include/linux/freezer.h b/include/linux/freezer.h
index 0621c5f86c39..b9e1e4200101 100644
--- a/include/linux/freezer.h
+++ b/include/linux/freezer.h
@@ -27,6 +27,11 @@ static inline bool frozen(struct task_struct *p)
 	return p->flags & PF_FROZEN;
 }
 
+static inline bool frozen_or_skipped(struct task_struct *p)
+{
+	return p->flags & (PF_FROZEN | PF_FREEZER_SKIP);
+}
+
 extern bool freezing_slow_path(struct task_struct *p);
 
 /*
@@ -270,6 +275,7 @@ static inline int freezable_schedule_hrtimeout_range(ktime_t *expires,
 
 #else /* !CONFIG_FREEZER */
 static inline bool frozen(struct task_struct *p) { return false; }
+static inline bool frozen_or_skipped(struct task_struct *p) { return false; }
 static inline bool freezing(struct task_struct *p) { return false; }
 static inline void __thaw_task(struct task_struct *t) {}
 
diff --git a/kernel/hung_task.c b/kernel/hung_task.c
index 396ebaebea3f..d2d4c4159b23 100644
--- a/kernel/hung_task.c
+++ b/kernel/hung_task.c
@@ -92,8 +92,8 @@ static void check_hung_task(struct task_struct *t, unsigned long timeout)
 	 * Ensure the task is not frozen.
 	 * Also, skip vfork and any other user process that freezer should skip.
 	 */
-	if (unlikely(t->flags & (PF_FROZEN | PF_FREEZER_SKIP)))
-	    return;
+	if (unlikely(frozen_or_skipped(t)))
+		return;
 
 	/*
 	 * When a freshly created task is scheduled once, changes its state to
-- 
2.31.1.818.g46aad6cb9e-goog

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