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.
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| @@ -44,7 +44,7 @@ int prof_on __read_mostly; · 43 unmodified lines | ||
| 44 | 44 | EXPORT_SYMBOL_GPL(prof_on); |
| 45 | 45 | |
| 46 | 46 | static cpumask_var_t prof_cpu_mask; |
| 47 | −#ifdef CONFIG_SMP | |
| 47 | +#if defined(CONFIG_SMP) && defined(CONFIG_PROC_FS) | |
| 48 | 48 | static DEFINE_PER_CPU(struct profile_hit *[2], cpu_profile_hits); |
| 49 | 49 | static DEFINE_PER_CPU(int, cpu_profile_flip); |
| 50 | 50 | static DEFINE_MUTEX(profile_flip_mutex); |
| @@ -202,7 +202,7 @@ int profile_event_unregister(enum profile_type type, struct notifier_block *n) · 151 unmodified lines | ||
| 202 | 202 | } |
| 203 | 203 | EXPORT_SYMBOL_GPL(profile_event_unregister); |
| 204 | 204 | |
| 205 | −#ifdef CONFIG_SMP | |
| 205 | +#if defined(CONFIG_SMP) && defined(CONFIG_PROC_FS) | |
| 206 | 206 | /* |
| 207 | 207 | * Each cpu has a pair of open-addressed hashtables for pending |
| 208 | 208 | * profile hits. read_profile() IPI's all cpus to request them |