Messages in this thread Patch in this message | | | Date | Wed, 23 Feb 2011 10:48:29 -0500 | From | Jason Baron <> | Subject | Re: [PATCH] jump label: introduce static_branch() interface |
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On Wed, Feb 23, 2011 at 11:11:25AM +0100, Peter Zijlstra wrote: > On Tue, 2011-02-22 at 17:28 -0500, Jason Baron wrote: > > @@ -33,7 +28,11 @@ struct _ddebug { > > #define _DPRINTK_FLAGS_PRINT (1<<0) /* printk() a message using > > the format */ > > #define _DPRINTK_FLAGS_DEFAULT 0 > > unsigned int flags:8; > > - char enabled; > > +#ifdef HAVE_JUMP_LABEL > > + struct jump_label_key enabled; > > +#else > > + int enabled; > > +#endif > > } __attribute__((aligned(8))); > > > > Also, didn't you promise Mathieu a comment explaining why dynamic debug > does funny things like this? :-) I mean we all know its because of the > cyclic header stuff involving atomic etc.. but I'm also quite sure we'll > all have forgotten about that in a few weeks time.
ok, how about something along these linnes:
diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h index 7e51b6f..5cc4771 100644 --- a/include/linux/dynamic_debug.h +++ b/include/linux/dynamic_debug.h @@ -1,6 +1,14 @@ #ifndef _DYNAMIC_DEBUG_H #define _DYNAMIC_DEBUG_H +/* + * When jump labels are disabled, they make use of atomic_read(). Since + * dynamic_debug.h gets included by kernel.h, the inclusion of jump_label.h by + * dynamic_debug.h and thus atomic.h (to get atomic_read()), would cause a + * circular dependency since atomic.h requires kernel.h. Thus, for dynamic debug + * we are explicitly including jump_label.h when jump labels are configured, and + * making use of a regular reads (non-atomic), when jump labels are disabled. + */ #if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL) #include <linux/jump_label.h> #endif
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