4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Arnd Bergmann arnd@arndb.de
commit ade356b99a4187578609f2a91c4d2ed88e4e70dc upstream.
A couple of functions and variables in the profile implementation are used only on SMP systems by the procfs code, but are unused if either procfs is disabled or in uniprocessor kernels. gcc prints a harmless warning about the unused symbols:
kernel/profile.c:243:13: error: 'profile_flip_buffers' defined but not used [-Werror=unused-function] static void profile_flip_buffers(void) ^ kernel/profile.c:266:13: error: 'profile_discard_flip_buffers' defined but not used [-Werror=unused-function] static void profile_discard_flip_buffers(void) ^ kernel/profile.c:330:12: error: 'profile_cpu_callback' defined but not used [-Werror=unused-function] static int profile_cpu_callback(struct notifier_block *info, ^
This adds further #ifdef to the file, to annotate exactly in which cases they are used. I have done several thousand ARM randconfig kernels with this patch applied and no longer get any warnings in this file.
Signed-off-by: Arnd Bergmann arnd@arndb.de Cc: Vlastimil Babka vbabka@suse.cz Cc: Robin Holt robinmholt@gmail.com Cc: Johannes Weiner hannes@cmpxchg.org Cc: Christoph Lameter cl@linux.com Cc: Tejun Heo tj@kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- kernel/profile.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/kernel/profile.c +++ b/kernel/profile.c @@ -44,7 +44,7 @@ int prof_on __read_mostly; EXPORT_SYMBOL_GPL(prof_on);
static cpumask_var_t prof_cpu_mask; -#ifdef CONFIG_SMP +#if defined(CONFIG_SMP) && defined(CONFIG_PROC_FS) static DEFINE_PER_CPU(struct profile_hit *[2], cpu_profile_hits); static DEFINE_PER_CPU(int, cpu_profile_flip); static DEFINE_MUTEX(profile_flip_mutex); @@ -201,7 +201,7 @@ int profile_event_unregister(enum profil } EXPORT_SYMBOL_GPL(profile_event_unregister);
-#ifdef CONFIG_SMP +#if defined(CONFIG_SMP) && defined(CONFIG_PROC_FS) /* * Each cpu has a pair of open-addressed hashtables for pending * profile hits. read_profile() IPI's all cpus to request them