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path: root/kernel/trace/ring_buffer.c
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Diffstat (limited to 'kernel/trace/ring_buffer.c')
-rw-r--r--kernel/trace/ring_buffer.c29
1 files changed, 11 insertions, 18 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index f58c9ad15830..2326b04c95c4 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -1193,9 +1193,6 @@ rb_remove_pages(struct ring_buffer_per_cpu *cpu_buffer, unsigned nr_pages)
struct list_head *p;
unsigned i;
- atomic_inc(&cpu_buffer->record_disabled);
- synchronize_sched();
-
spin_lock_irq(&cpu_buffer->reader_lock);
rb_head_page_deactivate(cpu_buffer);
@@ -1211,12 +1208,9 @@ rb_remove_pages(struct ring_buffer_per_cpu *cpu_buffer, unsigned nr_pages)
return;
rb_reset_cpu(cpu_buffer);
- spin_unlock_irq(&cpu_buffer->reader_lock);
-
rb_check_pages(cpu_buffer);
- atomic_dec(&cpu_buffer->record_disabled);
-
+ spin_unlock_irq(&cpu_buffer->reader_lock);
}
static void
@@ -1227,9 +1221,6 @@ rb_insert_pages(struct ring_buffer_per_cpu *cpu_buffer,
struct list_head *p;
unsigned i;
- atomic_inc(&cpu_buffer->record_disabled);
- synchronize_sched();
-
spin_lock_irq(&cpu_buffer->reader_lock);
rb_head_page_deactivate(cpu_buffer);
@@ -1242,11 +1233,9 @@ rb_insert_pages(struct ring_buffer_per_cpu *cpu_buffer,
list_add_tail(&bpage->list, cpu_buffer->pages);
}
rb_reset_cpu(cpu_buffer);
- spin_unlock_irq(&cpu_buffer->reader_lock);
-
rb_check_pages(cpu_buffer);
- atomic_dec(&cpu_buffer->record_disabled);
+ spin_unlock_irq(&cpu_buffer->reader_lock);
}
/**
@@ -1254,11 +1243,6 @@ rb_insert_pages(struct ring_buffer_per_cpu *cpu_buffer,
* @buffer: the buffer to resize.
* @size: the new size.
*
- * The tracer is responsible for making sure that the buffer is
- * not being used while changing the size.
- * Note: We may be able to change the above requirement by using
- * RCU synchronizations.
- *
* Minimum size is 2 * BUF_PAGE_SIZE.
*
* Returns -1 on failure.
@@ -1290,6 +1274,11 @@ int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size)
if (size == buffer_size)
return size;
+ atomic_inc(&buffer->record_disabled);
+
+ /* Make sure all writers are done with this buffer. */
+ synchronize_sched();
+
mutex_lock(&buffer->mutex);
get_online_cpus();
@@ -1352,6 +1341,8 @@ int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size)
put_online_cpus();
mutex_unlock(&buffer->mutex);
+ atomic_dec(&buffer->record_disabled);
+
return size;
free_pages:
@@ -1361,6 +1352,7 @@ int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size)
}
put_online_cpus();
mutex_unlock(&buffer->mutex);
+ atomic_dec(&buffer->record_disabled);
return -ENOMEM;
/*
@@ -1370,6 +1362,7 @@ int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size)
out_fail:
put_online_cpus();
mutex_unlock(&buffer->mutex);
+ atomic_dec(&buffer->record_disabled);
return -1;
}
EXPORT_SYMBOL_GPL(ring_buffer_resize);