Skip to content

Commit

Permalink
tracing/ring-buffer: don't annotate rb_cpu_notify with __cpuinit
Browse files Browse the repository at this point in the history
Impact: remove a section warning

CONFIG_DEBUG_SECTION_MISMATCH raises the following warning on -tip:

  WARNING: kernel/trace/built-in.o(.text+0x5bc5): Section mismatch in
  reference from the function ring_buffer_alloc() to the function
  .cpuinit.text:rb_cpu_notify()
  The function ring_buffer_alloc() references
  the function __cpuinit rb_cpu_notify().

This is actually harmless. The code in the ring buffer don't build
rb_cpu_notify and other cpu hotplug stuffs when !CONFIG_HOTPLUG_CPU
so we have no risk to reference freed memory here (it would even
be harmless if we unconditionally build it because register_cpu_notifier
would do nothing when !CONFIG_HOTPLUG_CPU.

But since ring_buffer_alloc() can be called everytime, we don't want it
to be annotated with __cpuinit so we drop the __cpuinit from
rb_cpu_notify.

This is not a waste of memory because it is only defined and used on
CONFIG_HOTPLUG_CPU.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <1237606416-22268-1-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
  • Loading branch information
Frederic Weisbecker authored and Ingo Molnar committed Mar 21, 2009
1 parent 22de89b commit 09c9e84
Showing 1 changed file with 4 additions and 4 deletions.
8 changes: 4 additions & 4 deletions kernel/trace/ring_buffer.c
Original file line number Diff line number Diff line change
Expand Up @@ -535,8 +535,8 @@ static void rb_free_cpu_buffer(struct ring_buffer_per_cpu *cpu_buffer)
extern int ring_buffer_page_too_big(void);

#ifdef CONFIG_HOTPLUG_CPU
static int __cpuinit rb_cpu_notify(struct notifier_block *self,
unsigned long action, void *hcpu);
static int rb_cpu_notify(struct notifier_block *self,
unsigned long action, void *hcpu);
#endif

/**
Expand Down Expand Up @@ -2784,8 +2784,8 @@ static __init int rb_init_debugfs(void)
fs_initcall(rb_init_debugfs);

#ifdef CONFIG_HOTPLUG_CPU
static int __cpuinit rb_cpu_notify(struct notifier_block *self,
unsigned long action, void *hcpu)
static int rb_cpu_notify(struct notifier_block *self,
unsigned long action, void *hcpu)
{
struct ring_buffer *buffer =
container_of(self, struct ring_buffer, cpu_notify);
Expand Down

0 comments on commit 09c9e84

Please sign in to comment.