perf tools: Sync addition of PERF_MEM_SNOOPX_PEER

Add a flag to the 'perf mem' data struct to signal that a request caused
a cache-to-cache transfer of a line from a peer of the requestor and
wasn't sourced from a lower cache level.

The line being moved from one peer cache to another has latency and
performance implications.

On Arm64 Neoverse systems the data source can indicate a cache-to-cache
transfer but not if the line is dirty or clean, so instead of
overloading HITM define a new flag that indicates this type of transfer.

Committer notes:

This really is not syncing with the kernel since the patch to the kernel
wasn't merged.

But we're going ahead of this as it seems trivial and is just a matter
of the perf kernel maintainers to give their ack or for us to find
another way of expressing this in the perf records synthesized in
userspace from the ARM64 hardware traces.

Reviewed-by: Leo Yan <[email protected]>
Signed-off-by: Ali Saidi <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Anshuman Khandual <[email protected]>
Cc: German Gomez <[email protected]>
Cc: Gustavo A. R. Silva <[email protected]>
Cc: Ian Rogers <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: James Clark <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: John Garry <[email protected]>
Cc: Kajol Jain <[email protected]>
Cc: Like Xu <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Mike Leach <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Timothy Hayes <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Leo Yan <[email protected]>
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

1 files changed, 1 insertions, 1 deletions

diff --git a/tools/include/uapi/linux/perf_event.h b/tools/include/uapi/linux/perf_event.h
index 4653834f078f..e2b77fbca91e 100644
--- a/tools/include/uapi/linux/perf_event.h
+++ b/tools/include/uapi/linux/perf_event.h
@@ -1310,7 +1310,7 @@ union perf_mem_data_src {
 #define PERF_MEM_SNOOP_SHIFT	19
 
 #define PERF_MEM_SNOOPX_FWD	0x01 /* forward */
-/* 1 free */
+#define PERF_MEM_SNOOPX_PEER	0x02 /* xfer from peer */
 #define PERF_MEM_SNOOPX_SHIFT  38
 
 /* locked instruction */