From b32614c03413f8a6025d8677c2b7c0ee976e63d4 Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Sun, 27 Nov 2016 00:13:34 +0100 Subject: tracing/rb: Convert to hotplug state machine Install the callbacks via the state machine. The notifier in struct ring_buffer is replaced by the multi instance interface. Upon __ring_buffer_alloc() invocation, cpuhp_state_add_instance() will invoke the trace_rb_cpu_prepare() on each CPU. This callback may now fail. This means __ring_buffer_alloc() will fail and cleanup (like previously) and during a CPU up event this failure will not allow the CPU to come up. Signed-off-by: Sebastian Andrzej Siewior Cc: Steven Rostedt Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20161126231350.10321-7-bigeasy@linutronix.de Signed-off-by: Thomas Gleixner --- include/linux/ring_buffer.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'include/linux/ring_buffer.h') diff --git a/include/linux/ring_buffer.h b/include/linux/ring_buffer.h index 4acc552e9279..b6d4568795a7 100644 --- a/include/linux/ring_buffer.h +++ b/include/linux/ring_buffer.h @@ -198,4 +198,10 @@ enum ring_buffer_flags { RB_FL_OVERWRITE = 1 << 0, }; +#ifdef CONFIG_RING_BUFFER +int trace_rb_cpu_prepare(unsigned int cpu, struct hlist_node *node); +#else +#define trace_rb_cpu_prepare NULL +#endif + #endif /* _LINUX_RING_BUFFER_H */ -- cgit