From: Linus Torvalds Date: Mon, 20 Nov 2006 19:47:18 +0000 (-0800) Subject: Add "pure_initcall" for static variable initialization X-Git-Tag: v2.6.19~62 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b3438f8266cb1f5010085ac47d7ad6a36a212164;p=linux-2.6 Add "pure_initcall" for static variable initialization This is a quick hack to overcome the fact that SRCU currently does not allow static initializers, and we need to sometimes initialize those things before any other initializers (even "core" ones) can do so. Currently we don't allow this at all for modules, and the only user that needs is right now is cpufreq. As reported by Thomas Gleixner: "Commit b4dfdbb3c707474a2254c5b4d7e62be31a4b7da9 ("[PATCH] cpufreq: make the transition_notifier chain use SRCU breaks cpu frequency notification users, which register the callback > on core_init level." Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Arjan van de Ven Cc: Andrew Morton , Signed-off-by: Linus Torvalds --- diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 86e69b7f91..dd0c2623e2 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -59,7 +59,7 @@ static int __init init_cpufreq_transition_notifier_list(void) srcu_init_notifier_head(&cpufreq_transition_notifier_list); return 0; } -core_initcall(init_cpufreq_transition_notifier_list); +pure_initcall(init_cpufreq_transition_notifier_list); static LIST_HEAD(cpufreq_governor_list); static DEFINE_MUTEX (cpufreq_governor_mutex); diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index 9d873163a7..e60d6f21fa 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -215,6 +215,8 @@ .notes : { *(.note.*) } :note #define INITCALLS \ + *(.initcall0.init) \ + *(.initcall0s.init) \ *(.initcall1.init) \ *(.initcall1s.init) \ *(.initcall2.init) \ diff --git a/include/linux/init.h b/include/linux/init.h index ff40ea118e..5eb5d24b76 100644 --- a/include/linux/init.h +++ b/include/linux/init.h @@ -93,6 +93,14 @@ extern void setup_arch(char **); static initcall_t __initcall_##fn##id __attribute_used__ \ __attribute__((__section__(".initcall" level ".init"))) = fn +/* + * A "pure" initcall has no dependencies on anything else, and purely + * initializes variables that couldn't be statically initialized. + * + * This only exists for built-in code, not for modules. + */ +#define pure_initcall(fn) __define_initcall("0",fn,1) + #define core_initcall(fn) __define_initcall("1",fn,1) #define core_initcall_sync(fn) __define_initcall("1s",fn,1s) #define postcore_initcall(fn) __define_initcall("2",fn,2)