Messages in this thread Patch in this message | | | Date | Wed, 20 Apr 2022 16:20:40 +0800 | From | Leo Yan <> | Subject | Re: [PATCH v5 2/5] perf: Add SNOOP_PEER flag to perf mem data struct |
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On Fri, Apr 08, 2022 at 07:53:41PM +0000, 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. > > Signed-off-by: Ali Saidi <alisaidi@amazon.com>
The patch looks good to me: Reviewed-by: Leo Yan <leo.yan@linaro.org>
Sine this is a common flag, it's better if x86 or PowerPC maintainers could take a look for this new snooping type. Thanks!
Leo
> --- > 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 82858b697c05..c9e58c79f3e5 100644 > --- a/include/uapi/linux/perf_event.h > +++ b/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 */ > -- > 2.32.0 >
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