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locking, tracing: Annotate tracing locks as raw
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The tracing locks can be taken in atomic context 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>
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Thomas Gleixner authored and Ingo Molnar committed Sep 13, 2011
1 parent 740969f commit 5389f6f
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Showing 3 changed files with 34 additions and 34 deletions.
52 changes: 26 additions & 26 deletions kernel/trace/ring_buffer.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -478,7 +478,7 @@ struct ring_buffer_per_cpu {
int cpu;
atomic_t record_disabled;
struct ring_buffer *buffer;
spinlock_t reader_lock; /* serialize readers */
raw_spinlock_t reader_lock; /* serialize readers */
arch_spinlock_t lock;
struct lock_class_key lock_key;
struct list_head *pages;
Expand Down Expand Up @@ -1062,7 +1062,7 @@ rb_allocate_cpu_buffer(struct ring_buffer *buffer, int cpu)

cpu_buffer->cpu = cpu;
cpu_buffer->buffer = buffer;
spin_lock_init(&cpu_buffer->reader_lock);
raw_spin_lock_init(&cpu_buffer->reader_lock);
lockdep_set_class(&cpu_buffer->reader_lock, buffer->reader_lock_key);
cpu_buffer->lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED;

Expand Down Expand Up @@ -1259,7 +1259,7 @@ rb_remove_pages(struct ring_buffer_per_cpu *cpu_buffer, unsigned nr_pages)
struct list_head *p;
unsigned i;

spin_lock_irq(&cpu_buffer->reader_lock);
raw_spin_lock_irq(&cpu_buffer->reader_lock);
rb_head_page_deactivate(cpu_buffer);

for (i = 0; i < nr_pages; i++) {
Expand All @@ -1277,7 +1277,7 @@ rb_remove_pages(struct ring_buffer_per_cpu *cpu_buffer, unsigned nr_pages)
rb_check_pages(cpu_buffer);

out:
spin_unlock_irq(&cpu_buffer->reader_lock);
raw_spin_unlock_irq(&cpu_buffer->reader_lock);
}

static void
Expand All @@ -1288,7 +1288,7 @@ rb_insert_pages(struct ring_buffer_per_cpu *cpu_buffer,
struct list_head *p;
unsigned i;

spin_lock_irq(&cpu_buffer->reader_lock);
raw_spin_lock_irq(&cpu_buffer->reader_lock);
rb_head_page_deactivate(cpu_buffer);

for (i = 0; i < nr_pages; i++) {
Expand All @@ -1303,7 +1303,7 @@ rb_insert_pages(struct ring_buffer_per_cpu *cpu_buffer,
rb_check_pages(cpu_buffer);

out:
spin_unlock_irq(&cpu_buffer->reader_lock);
raw_spin_unlock_irq(&cpu_buffer->reader_lock);
}

/**
Expand Down Expand Up @@ -2804,9 +2804,9 @@ void ring_buffer_iter_reset(struct ring_buffer_iter *iter)

cpu_buffer = iter->cpu_buffer;

spin_lock_irqsave(&cpu_buffer->reader_lock, flags);
raw_spin_lock_irqsave(&cpu_buffer->reader_lock, flags);
rb_iter_reset(iter);
spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);
raw_spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);
}
EXPORT_SYMBOL_GPL(ring_buffer_iter_reset);

Expand Down Expand Up @@ -3265,12 +3265,12 @@ ring_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts,
again:
local_irq_save(flags);
if (dolock)
spin_lock(&cpu_buffer->reader_lock);
raw_spin_lock(&cpu_buffer->reader_lock);
event = rb_buffer_peek(cpu_buffer, ts, lost_events);
if (event && event->type_len == RINGBUF_TYPE_PADDING)
rb_advance_reader(cpu_buffer);
if (dolock)
spin_unlock(&cpu_buffer->reader_lock);
raw_spin_unlock(&cpu_buffer->reader_lock);
local_irq_restore(flags);

if (event && event->type_len == RINGBUF_TYPE_PADDING)
Expand All @@ -3295,9 +3295,9 @@ ring_buffer_iter_peek(struct ring_buffer_iter *iter, u64 *ts)
unsigned long flags;

again:
spin_lock_irqsave(&cpu_buffer->reader_lock, flags);
raw_spin_lock_irqsave(&cpu_buffer->reader_lock, flags);
event = rb_iter_peek(iter, ts);
spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);
raw_spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);

if (event && event->type_len == RINGBUF_TYPE_PADDING)
goto again;
Expand Down Expand Up @@ -3337,7 +3337,7 @@ ring_buffer_consume(struct ring_buffer *buffer, int cpu, u64 *ts,
cpu_buffer = buffer->buffers[cpu];
local_irq_save(flags);
if (dolock)
spin_lock(&cpu_buffer->reader_lock);
raw_spin_lock(&cpu_buffer->reader_lock);

event = rb_buffer_peek(cpu_buffer, ts, lost_events);
if (event) {
Expand All @@ -3346,7 +3346,7 @@ ring_buffer_consume(struct ring_buffer *buffer, int cpu, u64 *ts,
}

if (dolock)
spin_unlock(&cpu_buffer->reader_lock);
raw_spin_unlock(&cpu_buffer->reader_lock);
local_irq_restore(flags);

out:
Expand Down Expand Up @@ -3438,11 +3438,11 @@ ring_buffer_read_start(struct ring_buffer_iter *iter)

cpu_buffer = iter->cpu_buffer;

spin_lock_irqsave(&cpu_buffer->reader_lock, flags);
raw_spin_lock_irqsave(&cpu_buffer->reader_lock, flags);
arch_spin_lock(&cpu_buffer->lock);
rb_iter_reset(iter);
arch_spin_unlock(&cpu_buffer->lock);
spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);
raw_spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);
}
EXPORT_SYMBOL_GPL(ring_buffer_read_start);

Expand Down Expand Up @@ -3477,7 +3477,7 @@ ring_buffer_read(struct ring_buffer_iter *iter, u64 *ts)
struct ring_buffer_per_cpu *cpu_buffer = iter->cpu_buffer;
unsigned long flags;

spin_lock_irqsave(&cpu_buffer->reader_lock, flags);
raw_spin_lock_irqsave(&cpu_buffer->reader_lock, flags);
again:
event = rb_iter_peek(iter, ts);
if (!event)
Expand All @@ -3488,7 +3488,7 @@ ring_buffer_read(struct ring_buffer_iter *iter, u64 *ts)

rb_advance_iter(iter);
out:
spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);
raw_spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);

return event;
}
Expand Down Expand Up @@ -3557,7 +3557,7 @@ void ring_buffer_reset_cpu(struct ring_buffer *buffer, int cpu)

atomic_inc(&cpu_buffer->record_disabled);

spin_lock_irqsave(&cpu_buffer->reader_lock, flags);
raw_spin_lock_irqsave(&cpu_buffer->reader_lock, flags);

if (RB_WARN_ON(cpu_buffer, local_read(&cpu_buffer->committing)))
goto out;
Expand All @@ -3569,7 +3569,7 @@ void ring_buffer_reset_cpu(struct ring_buffer *buffer, int cpu)
arch_spin_unlock(&cpu_buffer->lock);

out:
spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);
raw_spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);

atomic_dec(&cpu_buffer->record_disabled);
}
Expand Down Expand Up @@ -3607,10 +3607,10 @@ int ring_buffer_empty(struct ring_buffer *buffer)
cpu_buffer = buffer->buffers[cpu];
local_irq_save(flags);
if (dolock)
spin_lock(&cpu_buffer->reader_lock);
raw_spin_lock(&cpu_buffer->reader_lock);
ret = rb_per_cpu_empty(cpu_buffer);
if (dolock)
spin_unlock(&cpu_buffer->reader_lock);
raw_spin_unlock(&cpu_buffer->reader_lock);
local_irq_restore(flags);

if (!ret)
Expand Down Expand Up @@ -3641,10 +3641,10 @@ int ring_buffer_empty_cpu(struct ring_buffer *buffer, int cpu)
cpu_buffer = buffer->buffers[cpu];
local_irq_save(flags);
if (dolock)
spin_lock(&cpu_buffer->reader_lock);
raw_spin_lock(&cpu_buffer->reader_lock);
ret = rb_per_cpu_empty(cpu_buffer);
if (dolock)
spin_unlock(&cpu_buffer->reader_lock);
raw_spin_unlock(&cpu_buffer->reader_lock);
local_irq_restore(flags);

return ret;
Expand Down Expand Up @@ -3841,7 +3841,7 @@ int ring_buffer_read_page(struct ring_buffer *buffer,
if (!bpage)
goto out;

spin_lock_irqsave(&cpu_buffer->reader_lock, flags);
raw_spin_lock_irqsave(&cpu_buffer->reader_lock, flags);

reader = rb_get_reader_page(cpu_buffer);
if (!reader)
Expand Down Expand Up @@ -3964,7 +3964,7 @@ int ring_buffer_read_page(struct ring_buffer *buffer,
memset(&bpage->data[commit], 0, BUF_PAGE_SIZE - commit);

out_unlock:
spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);
raw_spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);

out:
return ret;
Expand Down
10 changes: 5 additions & 5 deletions kernel/trace/trace.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -341,7 +341,7 @@ unsigned long trace_flags = TRACE_ITER_PRINT_PARENT | TRACE_ITER_PRINTK |
TRACE_ITER_GRAPH_TIME | TRACE_ITER_RECORD_CMD | TRACE_ITER_OVERWRITE;

static int trace_stop_count;
static DEFINE_SPINLOCK(tracing_start_lock);
static DEFINE_RAW_SPINLOCK(tracing_start_lock);

static void wakeup_work_handler(struct work_struct *work)
{
Expand Down Expand Up @@ -960,7 +960,7 @@ void tracing_start(void)
if (tracing_disabled)
return;

spin_lock_irqsave(&tracing_start_lock, flags);
raw_spin_lock_irqsave(&tracing_start_lock, flags);
if (--trace_stop_count) {
if (trace_stop_count < 0) {
/* Someone screwed up their debugging */
Expand All @@ -985,7 +985,7 @@ void tracing_start(void)

ftrace_start();
out:
spin_unlock_irqrestore(&tracing_start_lock, flags);
raw_spin_unlock_irqrestore(&tracing_start_lock, flags);
}

/**
Expand All @@ -1000,7 +1000,7 @@ void tracing_stop(void)
unsigned long flags;

ftrace_stop();
spin_lock_irqsave(&tracing_start_lock, flags);
raw_spin_lock_irqsave(&tracing_start_lock, flags);
if (trace_stop_count++)
goto out;

Expand All @@ -1018,7 +1018,7 @@ void tracing_stop(void)
arch_spin_unlock(&ftrace_max_lock);

out:
spin_unlock_irqrestore(&tracing_start_lock, flags);
raw_spin_unlock_irqrestore(&tracing_start_lock, flags);
}

void trace_stop_cmdline_recording(void);
Expand Down
6 changes: 3 additions & 3 deletions kernel/trace/trace_irqsoff.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -23,7 +23,7 @@ static int tracer_enabled __read_mostly;

static DEFINE_PER_CPU(int, tracing_cpu);

static DEFINE_SPINLOCK(max_trace_lock);
static DEFINE_RAW_SPINLOCK(max_trace_lock);

enum {
TRACER_IRQS_OFF = (1 << 1),
Expand Down Expand Up @@ -321,7 +321,7 @@ check_critical_timing(struct trace_array *tr,
if (!report_latency(delta))
goto out;

spin_lock_irqsave(&max_trace_lock, flags);
raw_spin_lock_irqsave(&max_trace_lock, flags);

/* check if we are still the max latency */
if (!report_latency(delta))
Expand All @@ -344,7 +344,7 @@ check_critical_timing(struct trace_array *tr,
max_sequence++;

out_unlock:
spin_unlock_irqrestore(&max_trace_lock, flags);
raw_spin_unlock_irqrestore(&max_trace_lock, flags);

out:
data->critical_sequence = max_sequence;
Expand Down

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