[for-next][PATCH 19/34] ftrace: Add missing check for existing hwlat thread

From: Erica Bugden The hwlat tracer uses a kernel thread to measure latencies. The function that creates this kernel thread, start_kthread(), can be called when the tracer is initialized and when the tracer is explicitly enabled. start_kthread() does not check if there is an existing hwlat

[for-next][PATCH 19/34] ftrace: Add missing check for existing hwlat thread

From: Erica Bugden The hwlat tracer uses a kernel thread to measure latencies. The function that creates this kernel thread, start_kthread(), can be called when the tracer is initialized and when the tracer is explicitly enabled. start_kthread() does not check if there is an existing hwlat