Commit 96a1a241 authored by Rasmus Villemoes's avatar Rasmus Villemoes Committed by Luis Chamberlain
Browse files

kernel/params.c: defer most of param_sysfs_init() to late_initcall time 



param_sysfs_init(), and in particular param_sysfs_builtin() is rather
time-consuming; for my board, it currently takes about 30ms.

That amounts to about 3% of the time budget I have from U-Boot hands
over control to linux and linux must assume responsibility for keeping
the external watchdog happy.

We must still continue to initialize module_kset at subsys_initcall
time, since otherwise any request_module() would fail in
mod_sysfs_init(). However, the bulk of the work in
param_sysfs_builtin(), namely populating /sys/module/*/version and/or
/sys/module/*/parameters/ for builtin modules, can be deferred to
late_initcall time - there's no userspace yet anyway to observe
contents of /sys or the lack thereof.

Signed-off-by: default avatarRasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: default avatarLuis Chamberlain <mcgrof@kernel.org>
parent 89a6b591

kernel/params.c

+19 −2
Original line number Diff line number Diff line
@@ -953,7 +953,11 @@ struct kobj_type module_ktype = { 
};



/*

 * param_sysfs_init - wrapper for built-in params support

 * param_sysfs_init - create "module" kset

 *

 * This must be done before the initramfs is unpacked and

 * request_module() thus becomes possible, because otherwise the

 * module load would fail in mod_sysfs_init.

 */

static int __init param_sysfs_init(void)

{
@@ -964,11 +968,24 @@ static int __init param_sysfs_init(void) 
		return -ENOMEM;

	}



	return 0;

}

subsys_initcall(param_sysfs_init);



/*

 * param_sysfs_builtin_init - add sysfs version and parameter

 * attributes for built-in modules

 */

static int __init param_sysfs_builtin_init(void)

{

	if (!module_kset)

		return -ENOMEM;



	version_sysfs_builtin();

	param_sysfs_builtin();



	return 0;

}

subsys_initcall(param_sysfs_init);

late_initcall(param_sysfs_builtin_init);



#endif /* CONFIG_SYSFS */