Commit 757455d4 authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Ingo Molnar
Browse files

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: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 2737c49f

kernel/latencytop.c

+7 −7
Original line number Original line Diff line number Diff line
@@ -58,7 +58,7 @@ 
#include <linux/list.h>

#include <linux/list.h>

#include <linux/stacktrace.h>

#include <linux/stacktrace.h>





static DEFINE_SPINLOCK(latency_lock);

static DEFINE_RAW_SPINLOCK(latency_lock);





#define MAXLR 128

#define MAXLR 128

static struct latency_record latency_record[MAXLR];

static struct latency_record latency_record[MAXLR];
@@ -72,19 +72,19 @@ void clear_all_latency_tracing(struct task_struct *p) 
	if (!latencytop_enabled)

	if (!latencytop_enabled)

		return;

		return;





	spin_lock_irqsave(&latency_lock, flags);

	raw_spin_lock_irqsave(&latency_lock, flags);

	memset(&p->latency_record, 0, sizeof(p->latency_record));

	memset(&p->latency_record, 0, sizeof(p->latency_record));

	p->latency_record_count = 0;

	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)

static void clear_global_latency_tracing(void)

{

{

	unsigned long flags;

	unsigned long flags;





	spin_lock_irqsave(&latency_lock, flags);

	raw_spin_lock_irqsave(&latency_lock, flags);

	memset(&latency_record, 0, sizeof(latency_record));

	memset(&latency_record, 0, sizeof(latency_record));

	spin_unlock_irqrestore(&latency_lock, flags);

	raw_spin_unlock_irqrestore(&latency_lock, flags);

}

}





static void __sched

static void __sched
@@ -190,7 +190,7 @@ __account_scheduler_latency(struct task_struct *tsk, int usecs, int inter) 
	lat.max = usecs;

	lat.max = usecs;

	store_stacktrace(tsk, &lat);

	store_stacktrace(tsk, &lat);





	spin_lock_irqsave(&latency_lock, flags);

	raw_spin_lock_irqsave(&latency_lock, flags);





	account_global_scheduler_latency(tsk, &lat);

	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));

	memcpy(&tsk->latency_record[i], &lat, sizeof(struct latency_record));





out_unlock:

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)

static int lstats_show(struct seq_file *m, void *v)

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