diff options
| author | Max Krummenacher <max.krummenacher@toradex.com> | 2018-03-13 11:32:58 +0100 |
|---|---|---|
| committer | Max Krummenacher <max.krummenacher@toradex.com> | 2018-03-13 11:32:58 +0100 |
| commit | 6fb9f3c8a4992f67dcb3ce413df2e22e96b2d400 (patch) | |
| tree | 6e3071b2f179a62b027669ac2a238383293bf941 /kernel/trace/blktrace.c | |
| parent | a126a5e5dc2fcc5cb36af14c89b440cc8e3bab30 (diff) | |
| parent | 8b5ab55d254f36e89b1b53aeac7223d2d102483e (diff) | |
Merge tag 'v4.4.121' into toradex_vf_4.4-nextColibri-VF_LXDE-Image_2.8b2.97-20180331
This is the 4.4.121 stable release
Diffstat (limited to 'kernel/trace/blktrace.c')
| -rw-r--r-- | kernel/trace/blktrace.c | 32 |
1 files changed, 22 insertions, 10 deletions
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c index a990824c8604..7ab5eafea8b2 100644 --- a/kernel/trace/blktrace.c +++ b/kernel/trace/blktrace.c @@ -57,7 +57,8 @@ static struct tracer_flags blk_tracer_flags = { }; /* Global reference count of probes */ -static atomic_t blk_probes_ref = ATOMIC_INIT(0); +static DEFINE_MUTEX(blk_probe_mutex); +static int blk_probes_ref; static void blk_register_tracepoints(void); static void blk_unregister_tracepoints(void); @@ -300,11 +301,26 @@ static void blk_trace_free(struct blk_trace *bt) kfree(bt); } +static void get_probe_ref(void) +{ + mutex_lock(&blk_probe_mutex); + if (++blk_probes_ref == 1) + blk_register_tracepoints(); + mutex_unlock(&blk_probe_mutex); +} + +static void put_probe_ref(void) +{ + mutex_lock(&blk_probe_mutex); + if (!--blk_probes_ref) + blk_unregister_tracepoints(); + mutex_unlock(&blk_probe_mutex); +} + static void blk_trace_cleanup(struct blk_trace *bt) { blk_trace_free(bt); - if (atomic_dec_and_test(&blk_probes_ref)) - blk_unregister_tracepoints(); + put_probe_ref(); } int blk_trace_remove(struct request_queue *q) @@ -522,8 +538,7 @@ int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev, if (cmpxchg(&q->blk_trace, NULL, bt)) goto err; - if (atomic_inc_return(&blk_probes_ref) == 1) - blk_register_tracepoints(); + get_probe_ref(); return 0; err: @@ -1466,9 +1481,7 @@ static int blk_trace_remove_queue(struct request_queue *q) if (bt == NULL) return -EINVAL; - if (atomic_dec_and_test(&blk_probes_ref)) - blk_unregister_tracepoints(); - + put_probe_ref(); blk_trace_free(bt); return 0; } @@ -1499,8 +1512,7 @@ static int blk_trace_setup_queue(struct request_queue *q, if (cmpxchg(&q->blk_trace, NULL, bt)) goto free_bt; - if (atomic_inc_return(&blk_probes_ref) == 1) - blk_register_tracepoints(); + get_probe_ref(); return 0; free_bt: |