Re: [PATCH v5 3/5] perf tools: sync addition of PERF_MEM_SNOOPX_PEER

From: German Gomez
Date: Mon Apr 11 2022 - 06:26:58 EST



On 08/04/2022 20:53, Ali Saidi wrote:
> 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.

I think it's fine to merge this and the previous commit rather than have
two commits with the same msg.

>
> Signed-off-by: Ali Saidi <alisaidi@xxxxxxxxxx>
> ---
> tools/include/uapi/linux/perf_event.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/tools/include/uapi/linux/perf_event.h b/tools/include/uapi/linux/perf_event.h
> index 82858b697c05..c9e58c79f3e5 100644
> --- a/tools/include/uapi/linux/perf_event.h
> +++ b/tools/include/uapi/linux/perf_event.h
> @@ -1308,7 +1308,7 @@ 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 */