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[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>
This commit is contained in:
Gerd Hoffmann 2006-07-01 04:36:18 -07:00 committed by Linus Torvalds
parent 27b678dd04
commit 8ec4d41f88
3 changed files with 23 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
arch/i386/kernel/alternative.c
View File

@ -168,6 +168,8 @@ void apply_alternatives(struct alt_instr *start, struct alt_instr *end)
}
}
#ifdef CONFIG_SMP
static void alternatives_smp_save(struct alt_instr *start, struct alt_instr *end)
{
struct alt_instr *a;
@ -328,6 +330,8 @@ void alternatives_smp_switch(int smp)
spin_unlock_irqrestore(&smp_alt, flags);
}
#endif
void __init alternative_instructions(void)
{
if (no_replacement) {
@ -349,6 +353,7 @@ void __init alternative_instructions(void)
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 @@ void __init alternative_instructions(void)
_text, _etext);
alternatives_smp_switch(0);
}
#endif
}

8
include/asm-i386/alternative.h
View File

@ -19,11 +19,19 @@ struct alt_instr {
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

9
include/asm-x86_64/alternative.h
View File

@ -17,11 +17,20 @@ struct alt_instr {
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