Re: [PATCH v3 1/6] powerpc/perf: Define big-endian version of perf_mem_data_src

Madhavan Srinivasan [off-list ref] writes:

On Wednesday 19 April 2017 10:20 AM, Michael Ellerman wrote:

quoted

It also occurred to me that we don't actually have to redefine the whole
union, it's only the bitfields that matter, so we could reduce the diff
to:

diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h
index c66a485a24ac..97152c79df6b 100644
--- a/include/uapi/linux/perf_event.h
+++ b/include/uapi/linux/perf_event.h

@@ -894,12 +894,23 @@ enum perf_callchain_context {
  union perf_mem_data_src {
  	__u64 val;
  	struct {
+#if defined(__LITTLE_ENDIAN_BITFIELD)
  		__u64   mem_op:5,	/* type of opcode */
  			mem_lvl:14,	/* memory hierarchy level */
  			mem_snoop:5,	/* snoop mode */
  			mem_lock:2,	/* lock instr */
  			mem_dtlb:7,	/* tlb access */
  			mem_rsvd:31;
+#elif defined(__BIG_ENDIAN_BITFIELD)
+		__u64	mem_rsvd:31,
+			mem_dtlb:7,	/* tlb access */
+			mem_lock:2,	/* lock instr */
+			mem_snoop:5,	/* snoop mode */
+			mem_lvl:14,	/* memory hierarchy level */
+			mem_op:5;	/* type of opcode */
+#else
+#error "Unknown endianness"
+#endif
  	};
  };

That looks better to me, thoughts?

Yep.  Looks fine to me and also tested the same.

I merged the original version, as that's what Peterz acked and I didn't
want to block the series any longer.

I'll send an incremental patch to do the cleanup.

cheers