Messages in this thread Patch in this message | | | Subject | Re: [PATCH v9 00/14] Add support for remote unwind | From | Hekuang <> | Date | Wed, 8 Jun 2016 15:33:22 +0800 |
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hi
在 2016/6/8 3:44, Arnaldo Carvalho de Melo 写道: > Em Fri, Jun 03, 2016 at 09:06:29AM +0200, Jiri Olsa escreveu: >> On Fri, Jun 03, 2016 at 03:33:09AM +0000, He Kuang wrote: >> >> SNIP >> >>> For using remote libunwind libraries, reference this: >>> http://thread.gmane.org/gmane.linux.kernel/2224430 >>> >>> and now we can use LIBUNWIND_DIR to specific custom dirctories >>> containing libunwind libs. >>> >>> Acked-by: Jiri Olsa <jolsa@kernel.org> for most patches except: >>> >>> v9: >>> - Change function unwind__register_ops() to static. >>> - Move up unwind__prepare_access() in thread__insert_map() and save >>> map_groups__remove() call. >>> - Enclose multiple line if/else into braces. >>> - Fix miss modified function declaration for unwind__prepare_access() >>> in patch 10. >> for patchset: >> >> Acked-by: Jiri Olsa <jolsa@kernel.org> > Ok, I'm applying it, after fixing 'perf test unwind', 'perf top --call-graph dwarf' > and 'perf trace --call-graph dwarf', but I have one question, is the > scenario where we collect on a x86_64 machine and want to do analysis on > a ARM64 or x86-32 machine supported? This should be the odd case now, Yes, it's supported.
But I never tested this before, so I just compiled libunwind for aarch64, and tested unwinding i686 perf.data on aarch64. Then I found another issue I've considered but missed at some version of this patch series.
In util/unwind-libunwind-local.c, PERF_REG_SP/IP is used, but those macros are assigned to the host platform, we should redefine them in the wrapper file, for example in "util/libunwind/x86_32.c".
After fixing this problem, i686 perf.data can be parsed on aarch64 machine. Since you've already applied the v9 patches, should I send patches based on the lastest tree as bug fixes or just update v9 patches?
Thank you.
Here is the modified part:
diff --git a/tools/perf/util/libunwind/arm64.c b/tools/perf/util/libunwind/arm64.c index 4fb5395..8a5c2fc 100644 --- a/tools/perf/util/libunwind/arm64.c +++ b/tools/perf/util/libunwind/arm64.c @@ -29,6 +29,11 @@ #ifdef NO_LIBUNWIND_DEBUG_FRAME_AARCH64 #define NO_LIBUNWIND_DEBUG_FRAME #endif + +#undef PERF_REG_IP +#undef PERF_REG_SP +#define PERF_REG_IP PERF_REG_ARM64_PC +#define PERF_REG_SP PERF_REG_ARM64_SP #include "util/unwind-libunwind-local.c"
struct unwind_libunwind_ops * diff --git a/tools/perf/util/libunwind/x86_32.c b/tools/perf/util/libunwind/x86_32.c index d98c17e..de21a39 100644 --- a/tools/perf/util/libunwind/x86_32.c +++ b/tools/perf/util/libunwind/x86_32.c @@ -31,6 +31,11 @@ #ifndef NO_LIBUNWIND_DEBUG_FRAME #define NO_LIBUNWIND_DEBUG_FRAME #endif + +#undef PERF_REG_IP +#undef PERF_REG_SP +#define PERF_REG_IP PERF_REG_X86_IP +#define PERF_REG_SP PERF_REG_X86_SP #include "util/unwind-libunwind-local.c"
struct unwind_libunwind_ops *
> but from a quick look I couldn't see this as being supported, is that > true or I was just lazy not to have tried this? > > - Arnaldo
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