[PATCH] SMP alternatives: skip with UP kernels
Hide the magic in alternative.h and provide some dummy inline functions
for the UP case (gcc should manage to optimize away these calls). No
changes in module.c.
Cc: Dave Jones <davej@codemonkey.org.uk>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/i386/kernel/alternative.c b/arch/i386/kernel/alternative.c
index 50eb0e0..7b421b3 100644
--- a/arch/i386/kernel/alternative.c
+++ b/arch/i386/kernel/alternative.c
@@ -168,6 +168,8 @@
}
}
+#ifdef CONFIG_SMP
+
static void alternatives_smp_save(struct alt_instr *start, struct alt_instr *end)
{
struct alt_instr *a;
@@ -328,6 +330,8 @@
spin_unlock_irqrestore(&smp_alt, flags);
}
+#endif
+
void __init alternative_instructions(void)
{
if (no_replacement) {
@@ -349,6 +353,7 @@
smp_alt_once = 1;
#endif
+#ifdef CONFIG_SMP
if (smp_alt_once) {
if (1 == num_possible_cpus()) {
printk(KERN_INFO "SMP alternatives: switching to UP code\n");
@@ -370,4 +375,5 @@
_text, _etext);
alternatives_smp_switch(0);
}
+#endif
}
diff --git a/include/asm-i386/alternative.h b/include/asm-i386/alternative.h
index c61bd1a..96adbab 100644
--- a/include/asm-i386/alternative.h
+++ b/include/asm-i386/alternative.h
@@ -19,11 +19,19 @@
extern void apply_alternatives(struct alt_instr *start, struct alt_instr *end);
struct module;
+#ifdef CONFIG_SMP
extern void alternatives_smp_module_add(struct module *mod, char *name,
void *locks, void *locks_end,
void *text, void *text_end);
extern void alternatives_smp_module_del(struct module *mod);
extern void alternatives_smp_switch(int smp);
+#else
+static inline void alternatives_smp_module_add(struct module *mod, char *name,
+ void *locks, void *locks_end,
+ void *text, void *text_end) {}
+static inline void alternatives_smp_module_del(struct module *mod) {}
+static inline void alternatives_smp_switch(int smp) {}
+#endif
#endif
diff --git a/include/asm-x86_64/alternative.h b/include/asm-x86_64/alternative.h
index 387c8f6..aa67bfd 100644
--- a/include/asm-x86_64/alternative.h
+++ b/include/asm-x86_64/alternative.h
@@ -17,11 +17,20 @@
extern void apply_alternatives(struct alt_instr *start, struct alt_instr *end);
struct module;
+
+#ifdef CONFIG_SMP
extern void alternatives_smp_module_add(struct module *mod, char *name,
void *locks, void *locks_end,
void *text, void *text_end);
extern void alternatives_smp_module_del(struct module *mod);
extern void alternatives_smp_switch(int smp);
+#else
+static inline void alternatives_smp_module_add(struct module *mod, char *name,
+ void *locks, void *locks_end,
+ void *text, void *text_end) {}
+static inline void alternatives_smp_module_del(struct module *mod) {}
+static inline void alternatives_smp_switch(int smp) {}
+#endif
#endif
