Messages in this thread Patch in this message | | | From | Leo Yan <> | Subject | [PATCH v7] perf: Add SNOOP_PEER flag to perf mem data struct | Date | Fri, 26 Aug 2022 14:05:56 +0800 |
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From: Ali Saidi <alisaidi@amazon.com>
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.
Update notes:
This patch is to sync the headers between kernel and user space, commit 2e21bcf0514a ("perf tools: Sync addition of PERF_MEM_SNOOPX_PEER") for updating kernel header has been merged in the mainline code.
Signed-off-by: Ali Saidi <alisaidi@amazon.com> Reviewed-by: Leo Yan <leo.yan@linaro.org> Reviewed-by: Kajol Jain<kjain@linux.ibm.com> Signed-off-by: Leo Yan <leo.yan@linaro.org> ---
Changes from v6: Added Leo's SoB.
include/uapi/linux/perf_event.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h index 03b370062741..581ed4bdc062 100644 --- a/include/uapi/linux/perf_event.h +++ b/include/uapi/linux/perf_event.h @@ -1313,7 +1313,7 @@ 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
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