From: Thomas Gleixner <tglx@linutronix.de>
Date: Thu, 17 Sep 2009 15:31:09 +0000 (+0200)
Subject: locking, latencytop: Annotate latency_lock as raw
X-Git-Tag: firefly_0821_release~3680^2~4310^2~15
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=757455d41c390da4ae8e06468ad097fe42eaab41;p=firefly-linux-kernel-4.4.55.git

locking, latencytop: Annotate latency_lock as raw

The latency_lock is lock can be taken in the guts of the
scheduler code and therefore cannot be preempted on -rt -
annotate it.

In mainline this change documents the low level nature of
the lock - otherwise there's no functional difference. Lockdep
and Sparse checking will work as usual.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---

diff --git a/kernel/latencytop.c b/kernel/latencytop.c
index 376066e10413..4ac8ebfcab59 100644
--- a/kernel/latencytop.c
+++ b/kernel/latencytop.c
@@ -58,7 +58,7 @@
 #include <linux/list.h>
 #include <linux/stacktrace.h>
 
-static DEFINE_SPINLOCK(latency_lock);
+static DEFINE_RAW_SPINLOCK(latency_lock);
 
 #define MAXLR 128
 static struct latency_record latency_record[MAXLR];
@@ -72,19 +72,19 @@ void clear_all_latency_tracing(struct task_struct *p)
 	if (!latencytop_enabled)
 		return;
 
-	spin_lock_irqsave(&latency_lock, flags);
+	raw_spin_lock_irqsave(&latency_lock, flags);
 	memset(&p->latency_record, 0, sizeof(p->latency_record));
 	p->latency_record_count = 0;
-	spin_unlock_irqrestore(&latency_lock, flags);
+	raw_spin_unlock_irqrestore(&latency_lock, flags);
 }
 
 static void clear_global_latency_tracing(void)
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&latency_lock, flags);
+	raw_spin_lock_irqsave(&latency_lock, flags);
 	memset(&latency_record, 0, sizeof(latency_record));
-	spin_unlock_irqrestore(&latency_lock, flags);
+	raw_spin_unlock_irqrestore(&latency_lock, flags);
 }
 
 static void __sched
@@ -190,7 +190,7 @@ __account_scheduler_latency(struct task_struct *tsk, int usecs, int inter)
 	lat.max = usecs;
 	store_stacktrace(tsk, &lat);
 
-	spin_lock_irqsave(&latency_lock, flags);
+	raw_spin_lock_irqsave(&latency_lock, flags);
 
 	account_global_scheduler_latency(tsk, &lat);
 
@@ -231,7 +231,7 @@ __account_scheduler_latency(struct task_struct *tsk, int usecs, int inter)
 	memcpy(&tsk->latency_record[i], &lat, sizeof(struct latency_record));
 
 out_unlock:
-	spin_unlock_irqrestore(&latency_lock, flags);
+	raw_spin_unlock_irqrestore(&latency_lock, flags);
 }
 
 static int lstats_show(struct seq_file *m, void *v)