From: Ali Saidi <[email protected]>
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.
Signed-off-by: Ali Saidi <[email protected]>
Reviewed-by: Leo Yan <[email protected]>
---
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 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 */
--
2.34.1
Em Thu, Aug 11, 2022 at 02:24:37PM +0800, Leo Yan escreveu:
> From: Ali Saidi <[email protected]>
>
> 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.
>
> Signed-off-by: Ali Saidi <[email protected]>
> Reviewed-by: Leo Yan <[email protected]>
I'm adding a:
Signed-off-by: Leo Yan <[email protected]>
To the patches you're sending that you are not the original author, as
per defined in:
Documentation/process/submitting-patches.rst
---
The Signed-off-by: tag indicates that the signer was involved in the
development of the patch, or that he/she was in the patch's delivery path.
---
If you disagree and want to retract the patch, please let me know, this
so far is speculative and is only on my local branch for testing.
- Arnaldo
> ---
> 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 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 */
> --
> 2.34.1
--
- Arnaldo