Re: [PATCH] perf: fix building error in x86_64 when dwarf unwind is on

[Wang Nan <wangnan0@huawei.com>]

On 2015/1/7 21:50, Namhyung Kim wrote:
> On Wed, Jan 7, 2015 at 9:28 PM, Wang Nan <wangnan0@huawei.com> wrote:
>> On 2015/1/7 16:39, Jiri Olsa wrote:
>>> On Wed, Jan 07, 2015 at 02:40:04PM +0900, Namhyung Kim wrote:
>>>> diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
>>>> index 67a03a825b3c..eb3e2f3e14b4 100644
>>>> --- a/tools/perf/Makefile.perf
>>>> +++ b/tools/perf/Makefile.perf
>>>> @@ -462,10 +462,12 @@ BUILTIN_OBJS += $(OUTPUT)builtin-bench.o
>>>>  # Benchmark modules
>>>>  BUILTIN_OBJS += $(OUTPUT)bench/sched-messaging.o
>>>>  BUILTIN_OBJS += $(OUTPUT)bench/sched-pipe.o
>>>> +ifeq ($(ARCH),x86)
>>>>  ifeq ($(RAW_ARCH),x86_64)
>>>>  BUILTIN_OBJS += $(OUTPUT)bench/mem-memcpy-x86-64-asm.o
>>>>  BUILTIN_OBJS += $(OUTPUT)bench/mem-memset-x86-64-asm.o
>>>>  endif
>>>> +endif
>>>
>>> isn't the check for x86 superfluous here? the x86_64 check is stronger
>>>
>>> otherwise it looks ok to me.. Wang Nan, could you please check
>>> if it fixes the issue for you?
>>>
>>
>> Sorry, although Namhyung Kim's patch solves my ARCH=x86 problem, it breaks ARM building:
>>
>> ...
>> | bench/../../../arch/x86/lib/memcpy_64.S: Assembler messages:
>> | bench/../../../arch/x86/lib/memcpy_64.S:27: Error: junk at end of line, first unrecognized character is `,'
>> | bench/../../../arch/x86/lib/memcpy_64.S:29: Error: bad instruction `movq %rdi,%rax'
>> | bench/../../../arch/x86/lib/memcpy_64.S:30: Error: bad instruction `movq %rdx,%rcx'
>> | bench/../../../arch/x86/lib/memcpy_64.S:31: Error: bad instruction `shrq $3,%rcx'
>> | bench/../../../arch/x86/lib/memcpy_64.S:32: Error: bad instruction `andl $7,%edx'
>> ...
> 
> Strange.. this code is included only if ARCH=x86 in config/Makefile:
> 
> # Additional ARCH settings for x86
> ifeq ($(ARCH),x86)
>   ifeq (${IS_64_BIT}, 1)
>     CFLAGS += -DHAVE_ARCH_X86_64_SUPPORT
>     ARCH_INCLUDE = ../../arch/x86/lib/memcpy_64.S ../../arch/x86/lib/memset_64.S
>     LIBUNWIND_LIBS = -lunwind -lunwind-x86_64
>   else
>     LIBUNWIND_LIBS = -lunwind -lunwind-x86
>   endif
>   NO_PERF_REGS := 0
> endif
> 
> Did your original patch build it without a problem?
> 

My original patch is free from this problem.

bench/mem-memset-x86-64-asm.S doesn't use ARCH_INCLUDE, it direct include "../../../arch/x86/lib/memset_64.S".

> 
>>
>> It builds x86_64 bench when I corss compiling perf for arm (use ARCH=arm). This is caused by Makefile.perf:
>>
>> ...
>> BUILTIN_OBJS += $(OUTPUT)bench/sched-pipe.o
>> ifeq ($(RAW_ARCH),x86_64)
>> BUILTIN_OBJS += $(OUTPUT)bench/mem-memcpy-x86-64-asm.o
>> BUILTIN_OBJS += $(OUTPUT)bench/mem-memset-x86-64-asm.o
>> endif
>> BUILTIN_OBJS += $(OUTPUT)bench/mem-memcpy.o
>> ...
>>
>> Which rely on RAW_ARCH, but RAW_ARCH is not a cross-compiling-friendly variable now.
> 
> That's why I added the extra ARCH check.
> 

With your additional ARCH check, ARM compiling is passed. However I suggest you not to
use $(RAW_ARCH) directly, because it is get from "uname -m", which reflects the arch of
build machine, not the arch of host machine (the machine perf will run on).

What about this:

---
diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
index 67a03a82..1f71a32 100644
--- a/tools/perf/Makefile.perf
+++ b/tools/perf/Makefile.perf
@@ -462,10 +462,12 @@ BUILTIN_OBJS += $(OUTPUT)builtin-bench.o
 # Benchmark modules
 BUILTIN_OBJS += $(OUTPUT)bench/sched-messaging.o
 BUILTIN_OBJS += $(OUTPUT)bench/sched-pipe.o
-ifeq ($(RAW_ARCH),x86_64)
+ifeq ($(ARCH), x86)
+ifeq ($(IS_64_BIT), 1)
 BUILTIN_OBJS += $(OUTPUT)bench/mem-memcpy-x86-64-asm.o
 BUILTIN_OBJS += $(OUTPUT)bench/mem-memset-x86-64-asm.o
 endif
+endif
 BUILTIN_OBJS += $(OUTPUT)bench/mem-memcpy.o
 BUILTIN_OBJS += $(OUTPUT)bench/futex-hash.o
 BUILTIN_OBJS += $(OUTPUT)bench/futex-wake.o

> Thanks,
> Namhyung
>