blktrace: make blk_tracer_enabled a bool flag
It doesn't have to be a counter, and it can be a bool flag instead.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <49C2F5D3.8090104@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index fb3bc53..73845b7 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -30,7 +30,7 @@
static unsigned int blktrace_seq __read_mostly = 1;
static struct trace_array *blk_tr;
-static int __read_mostly blk_tracer_enabled;
+static bool blk_tracer_enabled __read_mostly;
/* Select an alternative, minimalistic output than the original one */
#define TRACE_BLK_OPT_CLASSIC 0x1
@@ -1111,9 +1111,7 @@
{
blk_tr = tr;
blk_tracer_start(tr);
- mutex_lock(&blk_probe_mutex);
- blk_tracer_enabled++;
- mutex_unlock(&blk_probe_mutex);
+ blk_tracer_enabled = true;
return 0;
}
@@ -1131,11 +1129,7 @@
if (!atomic_read(&blk_probes_ref))
return;
- mutex_lock(&blk_probe_mutex);
- blk_tracer_enabled--;
- WARN_ON(blk_tracer_enabled < 0);
- mutex_unlock(&blk_probe_mutex);
-
+ blk_tracer_enabled = false;
blk_tracer_stop(tr);
}