From e1783a240f491fb233f04edc042e16b18a7a79ba Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Tue, 5 Jan 2010 15:34:50 +0900 Subject: 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 Acked-by: Rusty Russell Signed-off-by: Tejun Heo --- include/linux/module.h | 36 ++++++++++++++---------------------- 1 file changed, 14 insertions(+), 22 deletions(-) (limited to 'include/linux/module.h') diff --git a/include/linux/module.h b/include/linux/module.h index 6cb1a3cab5d3..2302f09ea2d9 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -18,6 +18,7 @@ #include #include +#include #include #include @@ -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; } -- cgit v1.2.3 From 79615760f380ec86cd58204744e774c33fab9211 Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Tue, 5 Jan 2010 15:34:50 +0900 Subject: local_t: Move local.h include to ringbuffer.c and ring_buffer_benchmark.c ringbuffer*.c are the last users of local.h. Remove the include from modules.h and add it to ringbuffer files. Signed-off-by: Christoph Lameter Signed-off-by: Tejun Heo --- include/linux/module.h | 1 - 1 file changed, 1 deletion(-) (limited to 'include/linux/module.h') diff --git a/include/linux/module.h b/include/linux/module.h index 2302f09ea2d9..7e74ae0051cc 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -17,7 +17,6 @@ #include #include -#include #include #include -- cgit v1.2.3 From 43cf38eb5cea91245502df3fcee4dbfc1c74dd1c Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 2 Feb 2010 14:38:57 +0900 Subject: percpu: add __percpu sparse annotations to core kernel subsystems Add __percpu sparse annotations to core subsystems. These annotations are to make sparse consider percpu variables to be in a different address space and warn if accessed without going through percpu accessors. This patch doesn't affect normal builds. Signed-off-by: Tejun Heo Reviewed-by: Christoph Lameter Acked-by: Paul E. McKenney Cc: Jens Axboe Cc: linux-mm@kvack.org Cc: Rusty Russell Cc: Dipankar Sarma Cc: Peter Zijlstra Cc: Andrew Morton Cc: Eric Biederman --- include/linux/module.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/module.h') diff --git a/include/linux/module.h b/include/linux/module.h index 7e74ae0051cc..dd618eb026aa 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -365,7 +365,7 @@ struct module struct module_ref { int count; - } *refptr; + } __percpu *refptr; #endif #ifdef CONFIG_CONSTRUCTORS -- cgit v1.2.3 From 5ed109103d73b0bafc92e860cead56725231384d Mon Sep 17 00:00:00 2001 From: Dave Young Date: Wed, 10 Mar 2010 15:24:06 -0800 Subject: sysctl extern cleanup: module Extern declarations in sysctl.c should be moved to their own header file, and then include them in relavant .c files. Move modprobe_path extern declaration to linux/kmod.h Move modules_disabled extern declaration to linux/module.h Signed-off-by: Dave Young Cc: Rusty Russell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/module.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/module.h') diff --git a/include/linux/module.h b/include/linux/module.h index dd618eb026aa..5e869ffd34aa 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -175,6 +175,7 @@ struct notifier_block; #ifdef CONFIG_MODULES +extern int modules_disabled; /* for sysctl */ /* Get/put a kernel symbol (calls must be symmetric) */ void *__symbol_get(const char *symbol); void *__symbol_get_gpl(const char *symbol); -- cgit v1.2.3