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>
This commit is contained in:
parent
38b7827fcd
commit
e1783a240f
|
@ -18,6 +18,7 @@
|
||||||
#include <linux/tracepoint.h>
|
#include <linux/tracepoint.h>
|
||||||
|
|
||||||
#include <asm/local.h>
|
#include <asm/local.h>
|
||||||
|
#include <linux/percpu.h>
|
||||||
#include <asm/module.h>
|
#include <asm/module.h>
|
||||||
|
|
||||||
#include <trace/events/module.h>
|
#include <trace/events/module.h>
|
||||||
|
@ -363,11 +364,9 @@ struct module
|
||||||
/* Destruction function. */
|
/* Destruction function. */
|
||||||
void (*exit)(void);
|
void (*exit)(void);
|
||||||
|
|
||||||
#ifdef CONFIG_SMP
|
struct module_ref {
|
||||||
char *refptr;
|
int count;
|
||||||
#else
|
} *refptr;
|
||||||
local_t ref;
|
|
||||||
#endif
|
|
||||||
#endif
|
#endif
|
||||||
|
|
||||||
#ifdef CONFIG_CONSTRUCTORS
|
#ifdef CONFIG_CONSTRUCTORS
|
||||||
|
@ -454,25 +453,16 @@ void __symbol_put(const char *symbol);
|
||||||
#define symbol_put(x) __symbol_put(MODULE_SYMBOL_PREFIX #x)
|
#define symbol_put(x) __symbol_put(MODULE_SYMBOL_PREFIX #x)
|
||||||
void symbol_put_addr(void *addr);
|
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
|
/* Sometimes we know we already have a refcount, and it's easier not
|
||||||
to handle the error case (which only happens with rmmod --wait). */
|
to handle the error case (which only happens with rmmod --wait). */
|
||||||
static inline void __module_get(struct module *module)
|
static inline void __module_get(struct module *module)
|
||||||
{
|
{
|
||||||
if (module) {
|
if (module) {
|
||||||
unsigned int cpu = get_cpu();
|
preempt_disable();
|
||||||
local_inc(__module_ref_addr(module, cpu));
|
__this_cpu_inc(module->refptr->count);
|
||||||
trace_module_get(module, _THIS_IP_,
|
trace_module_get(module, _THIS_IP_,
|
||||||
local_read(__module_ref_addr(module, cpu)));
|
__this_cpu_read(module->refptr->count));
|
||||||
put_cpu();
|
preempt_enable();
|
||||||
}
|
}
|
||||||
}
|
}
|
||||||
|
|
||||||
|
@ -481,15 +471,17 @@ static inline int try_module_get(struct module *module)
|
||||||
int ret = 1;
|
int ret = 1;
|
||||||
|
|
||||||
if (module) {
|
if (module) {
|
||||||
unsigned int cpu = get_cpu();
|
preempt_disable();
|
||||||
|
|
||||||
if (likely(module_is_live(module))) {
|
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_,
|
trace_module_get(module, _THIS_IP_,
|
||||||
local_read(__module_ref_addr(module, cpu)));
|
__this_cpu_read(module->refptr->count));
|
||||||
}
|
}
|
||||||
else
|
else
|
||||||
ret = 0;
|
ret = 0;
|
||||||
put_cpu();
|
|
||||||
|
preempt_enable();
|
||||||
}
|
}
|
||||||
return ret;
|
return ret;
|
||||||
}
|
}
|
||||||
|
|
|
@ -474,9 +474,10 @@ static void module_unload_init(struct module *mod)
|
||||||
|
|
||||||
INIT_LIST_HEAD(&mod->modules_which_use_me);
|
INIT_LIST_HEAD(&mod->modules_which_use_me);
|
||||||
for_each_possible_cpu(cpu)
|
for_each_possible_cpu(cpu)
|
||||||
local_set(__module_ref_addr(mod, cpu), 0);
|
per_cpu_ptr(mod->refptr, cpu)->count = 0;
|
||||||
|
|
||||||
/* Hold reference count during initialization. */
|
/* Hold reference count during initialization. */
|
||||||
local_set(__module_ref_addr(mod, raw_smp_processor_id()), 1);
|
__this_cpu_write(mod->refptr->count, 1);
|
||||||
/* Backwards compatibility macros put refcount during init. */
|
/* Backwards compatibility macros put refcount during init. */
|
||||||
mod->waiter = current;
|
mod->waiter = current;
|
||||||
}
|
}
|
||||||
|
@ -619,7 +620,7 @@ unsigned int module_refcount(struct module *mod)
|
||||||
int cpu;
|
int cpu;
|
||||||
|
|
||||||
for_each_possible_cpu(cpu)
|
for_each_possible_cpu(cpu)
|
||||||
total += local_read(__module_ref_addr(mod, cpu));
|
total += per_cpu_ptr(mod->refptr, cpu)->count;
|
||||||
return total;
|
return total;
|
||||||
}
|
}
|
||||||
EXPORT_SYMBOL(module_refcount);
|
EXPORT_SYMBOL(module_refcount);
|
||||||
|
@ -796,14 +797,15 @@ static struct module_attribute refcnt = {
|
||||||
void module_put(struct module *module)
|
void module_put(struct module *module)
|
||||||
{
|
{
|
||||||
if (module) {
|
if (module) {
|
||||||
unsigned int cpu = get_cpu();
|
preempt_disable();
|
||||||
local_dec(__module_ref_addr(module, cpu));
|
__this_cpu_dec(module->refptr->count);
|
||||||
|
|
||||||
trace_module_put(module, _RET_IP_,
|
trace_module_put(module, _RET_IP_,
|
||||||
local_read(__module_ref_addr(module, cpu)));
|
__this_cpu_read(module->refptr->count));
|
||||||
/* Maybe they're waiting for us to drop reference? */
|
/* Maybe they're waiting for us to drop reference? */
|
||||||
if (unlikely(!module_is_live(module)))
|
if (unlikely(!module_is_live(module)))
|
||||||
wake_up_process(module->waiter);
|
wake_up_process(module->waiter);
|
||||||
put_cpu();
|
preempt_enable();
|
||||||
}
|
}
|
||||||
}
|
}
|
||||||
EXPORT_SYMBOL(module_put);
|
EXPORT_SYMBOL(module_put);
|
||||||
|
@ -1394,9 +1396,9 @@ static void free_module(struct module *mod)
|
||||||
kfree(mod->args);
|
kfree(mod->args);
|
||||||
if (mod->percpu)
|
if (mod->percpu)
|
||||||
percpu_modfree(mod->percpu);
|
percpu_modfree(mod->percpu);
|
||||||
#if defined(CONFIG_MODULE_UNLOAD) && defined(CONFIG_SMP)
|
#if defined(CONFIG_MODULE_UNLOAD)
|
||||||
if (mod->refptr)
|
if (mod->refptr)
|
||||||
percpu_modfree(mod->refptr);
|
free_percpu(mod->refptr);
|
||||||
#endif
|
#endif
|
||||||
/* Free lock-classes: */
|
/* Free lock-classes: */
|
||||||
lockdep_free_key_range(mod->module_core, mod->core_size);
|
lockdep_free_key_range(mod->module_core, mod->core_size);
|
||||||
|
@ -2159,9 +2161,8 @@ static noinline struct module *load_module(void __user *umod,
|
||||||
mod = (void *)sechdrs[modindex].sh_addr;
|
mod = (void *)sechdrs[modindex].sh_addr;
|
||||||
kmemleak_load_module(mod, hdr, sechdrs, secstrings);
|
kmemleak_load_module(mod, hdr, sechdrs, secstrings);
|
||||||
|
|
||||||
#if defined(CONFIG_MODULE_UNLOAD) && defined(CONFIG_SMP)
|
#if defined(CONFIG_MODULE_UNLOAD)
|
||||||
mod->refptr = percpu_modalloc(sizeof(local_t), __alignof__(local_t),
|
mod->refptr = alloc_percpu(struct module_ref);
|
||||||
mod->name);
|
|
||||||
if (!mod->refptr) {
|
if (!mod->refptr) {
|
||||||
err = -ENOMEM;
|
err = -ENOMEM;
|
||||||
goto free_init;
|
goto free_init;
|
||||||
|
@ -2393,8 +2394,8 @@ static noinline struct module *load_module(void __user *umod,
|
||||||
kobject_put(&mod->mkobj.kobj);
|
kobject_put(&mod->mkobj.kobj);
|
||||||
free_unload:
|
free_unload:
|
||||||
module_unload_free(mod);
|
module_unload_free(mod);
|
||||||
#if defined(CONFIG_MODULE_UNLOAD) && defined(CONFIG_SMP)
|
#if defined(CONFIG_MODULE_UNLOAD)
|
||||||
percpu_modfree(mod->refptr);
|
free_percpu(mod->refptr);
|
||||||
free_init:
|
free_init:
|
||||||
#endif
|
#endif
|
||||||
module_free(mod, mod->module_init);
|
module_free(mod, mod->module_init);
|
||||||
|
|
Loading…
Reference in New Issue