irqtrace-option-off-compile-fix

PATCH In review Tim Chen 3 participants 9 messages Jul 11, 2006

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Tim Chen

author

2006-07-11 01:00 UTC #0 lore raw

PATCH 1/1 irqtrace-option-off-compile-fix

When CONFIG_TRACE_IRQFLAGS_SUPPORT is turned off, the latest kernel has compile errors. The patch below fix the problems.

Regards,
Tim Chen

Signed-off-by Tim Chen <[email protected]>

include/linux/irqflags.h +13 ~~-14~~

index 412e025..2dd865f 100644
@@ -41,10 +41,10 @@
 # define INIT_TRACE_IRQFLAGS
 #endif
 
-#ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT
-
 #include <asm/irqflags.h>
 
+#ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT
+
 #define local_irq_enable() \
 	do { trace_hardirqs_on(); raw_local_irq_enable(); } while (0)
 #define local_irq_disable() \

@@ -62,24 +62,24 @@
 			raw_local_irq_restore(flags);		\
 		}						\
 	} while (0)
+#define safe_halt()						\
+	do {							\
+		trace_hardirqs_on();				\
+		raw_safe_halt();				\
+	} while (0)
+
 #else /* !CONFIG_TRACE_IRQFLAGS_SUPPORT */
 /*
  * The local_irq_*() APIs are equal to the raw_local_irq*()
  * if !TRACE_IRQFLAGS.
  */
-# define raw_local_irq_disable()	local_irq_disable()
-# define raw_local_irq_enable()		local_irq_enable()
-# define raw_local_irq_save(flags)	local_irq_save(flags)
-# define raw_local_irq_restore(flags)	local_irq_restore(flags)
+#define local_irq_disable()		raw_local_irq_disable()
+#define local_irq_enable()		raw_local_irq_enable()
+#define local_irq_save(flags)		raw_local_irq_save(flags)
+#define local_irq_restore(flags)	raw_local_irq_restore(flags)
+#define safe_halt()			raw_safe_halt()
 #endif /* CONFIG_TRACE_IRQFLAGS_SUPPORT */
 
-#ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT
-#define safe_halt()						\
-	do {							\
-		trace_hardirqs_on();				\
-		raw_safe_halt();				\
-	} while (0)
-
 #define local_save_flags(flags)		raw_local_save_flags(flags)
 
 #define irqs_disabled()						\

@@ -91,6 +91,5 @@
 })
 
 #define irqs_disabled_flags(flags)	raw_irqs_disabled_flags(flags)
-#endif		/* CONFIG_X86 */
 
 #endif

Arjan van de Ven

2006-07-11 07:13 UTC #1 lore raw

Quoted 2 lines · Tim Chen

When CONFIG_TRACE_IRQFLAGS_SUPPORT is turned off, the latest kernel has compile errors. The patch below fix the problems.

Hi,

which architecture did you see this on? (asking because IA64 and PPC compile just fine without this, and for x86 and x86-64 this is not an option you can turn off as user, it's not a user selectable config option but it's a "I have this feature in arch" option)

Greetings,
Arjan van de Ven

Tim Chen

author

2006-07-11 17:04 UTC #2 lore raw

I was testing on x86_64 and turned off the option in arch/x86_64/Kconfig.debug.

When the option is turned off, the following functions become undefined:
local_irq_disable()
local_irq_enable()
local_irq_save(flags)
local_irq_restore(flags)
safe_halt()
local_save_flags()
irqs_disabled()
irqs_disabled_flags(flags)

It seems plausible that some users may want to avoid the overhead of tracing IRQFLAGS by turning the option off.

Regards,
Tim Chen

Quoted 14 lines · Arjan van de Ven

Quoted 2 lines · Tim Chen
When CONFIG_TRACE_IRQFLAGS_SUPPORT is turned off, the latest kernel has compile errors. The patch below fix the problems.
Hi,
which architecture did you see this on? (asking because IA64 and PPC compile just fine without this, and for x86 and x86-64 this is not an option you can turn off as user, it's not a user selectable config option but it's a "I have this feature in arch" option)
Greetings,
Arjan van de Ven

Arjan van de Ven

2006-07-11 17:13 UTC #3 lore raw

Quoted 13 lines · Tim Chen

I was testing on x86_64 and turned off the option in arch/x86_64/Kconfig.debug.
When the option is turned off, the following functions become undefined:
local_irq_disable()
local_irq_enable()
local_irq_save(flags)
local_irq_restore(flags)
safe_halt()
local_save_flags()
irqs_disabled()
irqs_disabled_flags(flags)

Quoted 2 lines

It seems plausible that some users may want to avoid the overhead of tracing IRQFLAGS by turning the option off.

eh that is a different config option!

Tim Chen

author

2006-07-11 17:18 UTC #4 lore raw

Quoted 14 lines · Arjan van de Ven

Quoted 13 lines · Tim Chen
I was testing on x86_64 and turned off the option in arch/x86_64/Kconfig.debug.
When the option is turned off, the following functions become undefined:
local_irq_disable()
local_irq_enable()
local_irq_save(flags)
local_irq_restore(flags)
safe_halt()
local_save_flags()
irqs_disabled()
irqs_disabled_flags(flags)

Quoted 4 lines

Quoted 2 lines
It seems plausible that some users may want to avoid the overhead of tracing IRQFLAGS by turning the option off.
eh that is a different config option!

My typo, it is TRACE_IRQFLAGS_SUPPORT in arch/x86_64/Kconfig.debug.

Arjan van de Ven

2006-07-11 18:05 UTC #5 lore raw

Quoted 15 lines · Tim Chen

Quoted 14 lines · Arjan van de Ven
Quoted 13 lines · Tim Chen
I was testing on x86_64 and turned off the option in arch/x86_64/Kconfig.debug.
When the option is turned off, the following functions become undefined:
local_irq_disable()
local_irq_enable()
local_irq_save(flags)
local_irq_restore(flags)
safe_halt()
local_save_flags()
irqs_disabled()
irqs_disabled_flags(flags)

Quoted 6 lines

Quoted 4 lines
Quoted 2 lines
It seems plausible that some users may want to avoid the overhead of tracing IRQFLAGS by turning the option off.
eh that is a different config option!
My typo, it is TRACE_IRQFLAGS_SUPPORT in arch/x86_64/Kconfig.debug.

that should never ever be user setable. That just says if you have support for the api.

The one you want is CONFIG_TRACE_IRQFLAGS .. which is the one that actually turns the tracing on

Tim Chen

author

2006-07-11 19:43 UTC #6 lore raw

Quoted 21 lines · Arjan van de Ven

Quoted 20 lines · Tim Chen
Quoted 18 lines · Arjan van de Ven
Quoted 13 lines · Tim Chen
I was testing on x86_64 and turned off the option in arch/x86_64/Kconfig.debug.
When the option is turned off, the following functions become undefined:
local_irq_disable()
local_irq_enable()
local_irq_save(flags)
local_irq_restore(flags)
safe_halt()
local_save_flags()
irqs_disabled()
irqs_disabled_flags(flags)
Quoted 2 lines
It seems plausible that some users may want to avoid the overhead of tracing IRQFLAGS by turning the option off.
eh that is a different config option!

Quoted 9 lines

Quoted 1 line
My typo, it is TRACE_IRQFLAGS_SUPPORT in arch/x86_64/Kconfig.debug.
that should never ever be user setable. That just says if you have support for the api.
The one you want is CONFIG_TRACE_IRQFLAGS .. which is the one that actually turns the tracing on

I could not turn off CONFIG_TRACE_IRQFLAGS_SUPPORT in .config directly. The command "scripts/kconfig/conf -s arch/x86_64/Kconfig" in Makefile overwrites changes made to CONFIG_TRACE_IRQFLAGS_SUPPORT in .config file. So this is always turned on in .config if the option TRACE_IRQFLAGS_SUPPORT is set in arch/x86_64/Kconfig.debug. I may be missing something. Any suggestions?

Ingo Molnar

2006-07-11 19:50 UTC #7 lore raw

Quoted 9 lines · Tim Chen

Quoted 2 lines
The one you want is CONFIG_TRACE_IRQFLAGS .. which is the one that actually turns the tracing on
I could not turn off CONFIG_TRACE_IRQFLAGS_SUPPORT in .config directly. The command "scripts/kconfig/conf -s arch/x86_64/Kconfig" in Makefile overwrites changes made to CONFIG_TRACE_IRQFLAGS_SUPPORT in .config file. So this is always turned on in .config if the option TRACE_IRQFLAGS_SUPPORT is set in arch/x86_64/Kconfig.debug. I may be missing something. Any suggestions?

correct, that flag is always set - it signals towards the core kernel that the architecture in question (x86_64) that it has trace-irqflags support. NOTE: this does not mean that irqflags tracing is turned on - that is another option: CONFIG_TRACE_IRQFLAGS.

unsetting the support flag makes no sense and will likely break the build. There is no overhead from irqflags tracing if it's turned off. (even if the CONFIG_TRACE_IRQFLAGS_SUPPORT option is set)

does this explain things? We could rename the boolean value to CONFIG_TRACE_IRQFLAGS_SUPPORT_AVAILABLE perhaps, to avoid future confusion.

Ingo

Tim Chen

author

2006-07-11 20:30 UTC #8 lore raw

Quoted 21 lines · Ingo Molnar

Quoted 9 lines · Tim Chen
Quoted 2 lines
The one you want is CONFIG_TRACE_IRQFLAGS .. which is the one that actually turns the tracing on
I could not turn off CONFIG_TRACE_IRQFLAGS_SUPPORT in .config directly. The command "scripts/kconfig/conf -s arch/x86_64/Kconfig" in Makefile overwrites changes made to CONFIG_TRACE_IRQFLAGS_SUPPORT in .config file. So this is always turned on in .config if the option TRACE_IRQFLAGS_SUPPORT is set in arch/x86_64/Kconfig.debug. I may be missing something. Any suggestions?
correct, that flag is always set - it signals towards the core kernel that the architecture in question (x86_64) that it has trace-irqflags support. NOTE: this does not mean that irqflags tracing is turned on - that is another option: CONFIG_TRACE_IRQFLAGS.
unsetting the support flag makes no sense and will likely break the build. There is no overhead from irqflags tracing if it's turned off. (even if the CONFIG_TRACE_IRQFLAGS_SUPPORT option is set)

Quoted 5 lines

does this explain things? We could rename the boolean value to CONFIG_TRACE_IRQFLAGS_SUPPORT_AVAILABLE perhaps, to avoid future confusion.
Ingo

Thanks for clarifying.