(Directing this patch to Perf-events maintainers for review.)
With the kernel facility of Linux performance counters, we want the user
level tool tools/perf to be cross compiled for MIPS platform. To do this,
we need to include unistd.h, add rmb() and cpu_relax() in perf.h.
Your review comments are especially required for the definition of rmb():
In perf.h, we need to have a proper rmb() for _all_ MIPS platforms. And
we don't have CONFIG_* things for use in here. Looking at barrier.h,
rmb() goes into barrier() and __sync() for CAVIUM OCTEON and other CPUs,
respectively. What's more, __sync() has different versions as well.
Referring to BARRIER() in dump_tlb.c, I propose the "common" definition
for perf tool rmb() in this patch. Do you have any comments?
In addition, for testing the kernel part code I sent several days
ago, I was using the "particular" rmb() version for 24K/34K/74K cores:
#define rmb() asm volatile( \
".set push\n\t" \
".set noreorder\n\t" \
".set mips2\n\t" \
"sync\n\t" \
".set pop" \
: /* no output */ \
: /* no input */ \
: "memory")
This is the definition of __sync() for CONFIG_CPU_HAS_SYNC.
Thanks,
Deng-Cheng
Signed-off-by: Deng-Cheng Zhu <dengcheng.zhu@xxxxxxxxx>
---
tools/perf/perf.h | 12 ++++++++++++
1 files changed, 12 insertions(+), 0 deletions(-)
diff --git a/tools/perf/perf.h b/tools/perf/perf.h
index 6fb379b..cd05284 100644
--- a/tools/perf/perf.h
+++ b/tools/perf/perf.h
@@ -73,6 +73,18 @@
#define cpu_relax() asm volatile("":::"memory")
#endif
+#ifdef __mips__
+#include "../../arch/mips/include/asm/unistd.h"
+#define rmb() asm volatile( \
+ ".set noreorder\n\t" \
+ "nop;nop;nop;nop;nop;nop;nop\n\t" \
+ ".set reorder" \
+ : /* no output */ \
+ : /* no input */ \
+ : "memory")
+#define cpu_relax() asm volatile("" ::: "memory")
+#endif
+
#include <time.h>
#include <unistd.h>
#include <sys/types.h>
