Messages in this thread Patch in this message | | | Subject | Re: [RFC][PATCH] tracing/module: Move tracepoint out of module.h | From | Steven Rostedt <> | Date | Thu, 26 Jan 2012 08:52:25 -0500 |
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On Thu, 2012-01-26 at 11:28 +0100, Ingo Molnar wrote:
> How much more do we save if we move all of try_module_get() out > of line? It still seems a rather thick inline function with > preempt section and all. I'd *really* suggest that it should all > be uninlined. >
Here's the #'s
text data bss dec hex filename 7489488 2249584 9719808 19458880 128eb40 vmlinux-prepatch text data bss dec hex filename 7482458 2248048 9719808 19450314 128c9ca vmlinux-postpatch text data bss dec hex filename 7477393 2248080 9719808 19445281 128b621 vmlinux-updatedpatch
Thus we get an additional 5k it seems, for a total of 13k savings.
The below patch is what I used. Note, since the tracepoint requires the instruction pointer, I created stub versions that call a "do_" version of the function to pass in the local instruction counter.
Rusty, can you give your acked-by on that patch?
Thanks!
-- Steve
diff --git a/include/linux/module.h b/include/linux/module.h index 3cb7839..2337f97 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -21,8 +21,6 @@ #include <linux/percpu.h> #include <asm/module.h> -#include <trace/events/module.h> - /* Not Yet Implemented */ #define MODULE_SUPPORTED_DEVICE(name) @@ -439,34 +437,17 @@ void __symbol_put(const char *symbol); #define symbol_put(x) __symbol_put(MODULE_SYMBOL_PREFIX #x) void symbol_put_addr(void *addr); -/* Sometimes we know we already have a refcount, and it's easier not - to handle the error case (which only happens with rmmod --wait). */ +extern void do_module_get(struct module *module, int ip); +extern int do_try_module_get(struct module *module, int ip); + static inline void __module_get(struct module *module) { - if (module) { - preempt_disable(); - __this_cpu_inc(module->refptr->incs); - trace_module_get(module, _THIS_IP_); - preempt_enable(); - } + do_module_get(module, _THIS_IP_); } static inline int try_module_get(struct module *module) { - int ret = 1; - - if (module) { - preempt_disable(); - - if (likely(module_is_live(module))) { - __this_cpu_inc(module->refptr->incs); - trace_module_get(module, _THIS_IP_); - } else - ret = 0; - - preempt_enable(); - } - return ret; + return do_try_module_get(module, _THIS_IP_); } extern void module_put(struct module *module); diff --git a/kernel/module.c b/kernel/module.c index 178333c..8955199 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -928,6 +928,42 @@ void module_put(struct module *module) } EXPORT_SYMBOL(module_put); +static void inc_module(struct module *module, unsigned long ip) +{ + __this_cpu_inc(module->refptr->incs); + trace_module_get(module, ip); +} + +/* Sometimes we know we already have a refcount, and it's easier not + to handle the error case (which only happens with rmmod --wait). */ +void do_module_get(struct module *module, int ip) +{ + if (module) { + preempt_disable(); + inc_module(module, ip); + preempt_enable(); + } +} +EXPORT_SYMBOL(do_module_get); + +int do_try_module_get(struct module *module, int ip) +{ + int ret = 1; + + if (module) { + preempt_disable(); + + if (likely(module_is_live(module))) + inc_module(module, ip); + else + ret = 0; + + preempt_enable(); + } + return ret; +} +EXPORT_SYMBOL(do_try_module_get); + #else /* !CONFIG_MODULE_UNLOAD */ static inline void print_unload_info(struct seq_file *m, struct module *mod) {
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