diff options
author | Christoph Lameter <cl@linux-foundation.org> | 2010-01-05 15:34:50 +0900 |
---|---|---|
committer | Tejun Heo <tj@kernel.org> | 2010-01-05 15:34:50 +0900 |
commit | e1783a240f491fb233f04edc042e16b18a7a79ba (patch) | |
tree | b523bf2db00fff96f1ab488168fc16ab56c372aa /include/linux/module.h | |
parent | 38b7827fcdd660f591d645bd3ae6644456a4773c (diff) |
module: Use this_cpu_xx to dynamically allocate counters
Use cpu ops to deal with the per cpu data instead of a local_t. Reduces memory
requirements, cache footprint and decreases cycle counts.
The this_cpu_xx operations are also used for !SMP mode. Otherwise we could
not drop the use of __module_ref_addr() which would make per cpu data handling
complicated. this_cpu_xx operations have their own fallback for !SMP.
V8-V9:
- Leave include asm/module.h since ringbuffer.c depends on it. Nothing else
does though. Another patch will deal with that.
- Remove spurious free.
Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'include/linux/module.h')
-rw-r--r-- | include/linux/module.h | 36 |
1 files changed, 14 insertions, 22 deletions
diff --git a/include/linux/module.h b/include/linux/module.h index 6cb1a3cab5d..2302f09ea2d 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -18,6 +18,7 @@ #include <linux/tracepoint.h> #include <asm/local.h> +#include <linux/percpu.h> #include <asm/module.h> #include <trace/events/module.h> @@ -363,11 +364,9 @@ struct module /* Destruction function. */ void (*exit)(void); -#ifdef CONFIG_SMP - char *refptr; -#else - local_t ref; -#endif + struct module_ref { + int count; + } *refptr; #endif #ifdef CONFIG_CONSTRUCTORS @@ -454,25 +453,16 @@ void __symbol_put(const char *symbol); #define symbol_put(x) __symbol_put(MODULE_SYMBOL_PREFIX #x) void symbol_put_addr(void *addr); -static inline local_t *__module_ref_addr(struct module *mod, int cpu) -{ -#ifdef CONFIG_SMP - return (local_t *) (mod->refptr + per_cpu_offset(cpu)); -#else - return &mod->ref; -#endif -} - /* Sometimes we know we already have a refcount, and it's easier not to handle the error case (which only happens with rmmod --wait). */ static inline void __module_get(struct module *module) { if (module) { - unsigned int cpu = get_cpu(); - local_inc(__module_ref_addr(module, cpu)); + preempt_disable(); + __this_cpu_inc(module->refptr->count); trace_module_get(module, _THIS_IP_, - local_read(__module_ref_addr(module, cpu))); - put_cpu(); + __this_cpu_read(module->refptr->count)); + preempt_enable(); } } @@ -481,15 +471,17 @@ static inline int try_module_get(struct module *module) int ret = 1; if (module) { - unsigned int cpu = get_cpu(); + preempt_disable(); + if (likely(module_is_live(module))) { - local_inc(__module_ref_addr(module, cpu)); + __this_cpu_inc(module->refptr->count); trace_module_get(module, _THIS_IP_, - local_read(__module_ref_addr(module, cpu))); + __this_cpu_read(module->refptr->count)); } else ret = 0; - put_cpu(); + + preempt_enable(); } return ret; } |