Re: Testers needed for LTTng 0.6.0pre1

At 2006/9/27 15:54-0400  Mathieu Desnoyers writes:
> 
> I would like you to test it on various architectures (and check for warnings) to
> see if I broke something when porting the LTTng instrumentation to markers.

The marker mechanism doesn't compile on ppc64. Neither the asm-powerpc
or asm-generic version of marker.h work.

The problem appears to be in the macro:

		asm volatile(	".section .markers, \"a\";\n\t" \
					".long %1, 0f, %2, %3;\n\t" \
					".previous;\n\t" \
					".align 32;\n\t" \
					"0:\n\t" \
					"li $0,%0;\n\t" \
				: "=r" (condition) : \
				"m" (*(#name)), \
				"m" (__mark_call_##name), \
				"m" (*format)); \

For the .long part, gcc ends up outputting something like:

long 0(9), 0f, 0(11), 0(3);

ie register relative addresses which the assembler barfs on.

Would something like the following be ok? (based on asm-generic version
- I did try to do get something working based on the asm-powerpc
version working, but so far without success):

#define MARK(name, format, args...) \
        do { \
                static marker_probe_func *__mark_call_##name = \
                                        __mark_empty_function; \
                volatile static char __marker_enable_##name = 0; \
                static struct _mark_marker_local { \
                        const char *local_name; \
                        volatile char *enable; \
                        marker_probe_func **call; \
                        const char *local_format; \
                } __attribute__((packed)) i __attribute__ ((section(".markers"))) \
		 __attribute__((__used__))  = \
                    { #name, &__marker_enable_##name, &__mark_call_##name, format }; \
                if (unlikely(__marker_enable_##name)) { \
                        preempt_disable(); \
                        (*__mark_call_##name)(format, ## args); \
                        preempt_enable_no_resched(); \
                } \
        } while(0)


There also seems to be a problem with fs/compat.c (~1514) with lttng_name
not being declared.

Chris
-- 
[email protected]
IBM OzLabs Linux Development Group, ADL
Canberra, Australia