linux-kernel - Re: [PATCH] Remove some PMU events for FUJITSU-MONAKA

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Message-ID: <96b323eb-15b2-4b60-8522-83bf2f57694b@linaro.org>
Date: Thu, 27 Feb 2025 10:53:53 +0000
From: James Clark <james.clark@...aro.org>
To: Yoshihiro Furudera <fj5100bi@...itsu.com>
Cc: John Garry <john.g.garry@...cle.com>, Will Deacon <will@...nel.org>,
 Mike Leach <mike.leach@...aro.org>, Leo Yan <leo.yan@...ux.dev>,
 Peter Zijlstra <peterz@...radead.org>, Ingo Molnar <mingo@...hat.com>,
 Arnaldo Carvalho de Melo <acme@...nel.org>,
 Namhyung Kim <namhyung@...nel.org>, Mark Rutland <mark.rutland@....com>,
 Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
 Jiri Olsa <jolsa@...nel.org>, Ian Rogers <irogers@...gle.com>,
 Adrian Hunter <adrian.hunter@...el.com>,
 "Liang, Kan" <kan.liang@...ux.intel.com>,
 linux-arm-kernel@...ts.infradead.org, linux-perf-users@...r.kernel.org,
 linux-kernel@...r.kernel.org, Akio Kakuno <fj3333bs@...jp.fujitsu.com>
Subject: Re: [PATCH] Remove some PMU events for FUJITSU-MONAKA



On 27/02/2025 5:40 am, Yoshihiro Furudera wrote:
> The following events are not counted properly:
> 
> 0x0037 LL_CACHE_MISS_RD
> 0x400B L3D_CACHE_LMISS_RD

These two are discoverable so will still appear in 
/sys/bus/event_source/devices/armv8_pmuv3_0/events/ if the hardware says 
they exist. It might be better to change the json strings of these two 
to warn that they don't work if that's the case, otherwise Perf will 
still list them and you'll be worse off.

> 0x0396 L2D_CACHE_REFILL_L3D_MISS
> 0x039A L2D_CACHE_REFILL_L3D_MISS_PRF
> 0x039B L2D_CACHE_REFILL_L3D_MISS_HWPRF
> 0x039C L2D_CACHE_REFILL_L3D_HIT
> 0x03A0 L2D_CACHE_REFILL_L3D_HIT_PRF
> 0x03A1 L2D_CACHE_REFILL_L3D_HIT_HWPRF
> 
> Specifically, these events are always counted as misses,
> regardless of whether the L3 prefetch is a hit or a miss.
> So I remove these events in l3_cache.json, ll_cache.json
> 
> Signed-off-by: Yoshihiro Furudera <fj5100bi@...itsu.com>
> ---
>   .../arch/arm64/fujitsu/monaka/l3_cache.json   | 34 -------------------
>   .../arch/arm64/fujitsu/monaka/ll_cache.json   |  4 ---
>   2 files changed, 38 deletions(-)
> 
> diff --git a/tools/perf/pmu-events/arch/arm64/fujitsu/monaka/l3_cache.json b/tools/perf/pmu-events/arch/arm64/fujitsu/monaka/l3_cache.json
> index 3f3e0d22ac68..917b9b5bf8bb 100644
> --- a/tools/perf/pmu-events/arch/arm64/fujitsu/monaka/l3_cache.json
> +++ b/tools/perf/pmu-events/arch/arm64/fujitsu/monaka/l3_cache.json
> @@ -37,11 +37,6 @@
>           "EventName": "L2D_CACHE_REFILL_L3D_CACHE_HWPRF",
>           "BriefDescription": "This event counts L2D_CACHE_REFILL_L3D_CACHE caused by hardware prefetch access."
>       },
> -    {
> -        "EventCode": "0x0396",
> -        "EventName": "L2D_CACHE_REFILL_L3D_MISS",
> -        "BriefDescription": "This event counts operations that cause a miss of the L3 cache."
> -    },
>       {
>           "EventCode": "0x0397",
>           "EventName": "L2D_CACHE_REFILL_L3D_MISS_DM",
> @@ -57,21 +52,6 @@
>           "EventName": "L2D_CACHE_REFILL_L3D_MISS_DM_WR",
>           "BriefDescription": "This event counts L2D_CACHE_REFILL_L3D_MISS caused by demand write access."
>       },
> -    {
> -        "EventCode": "0x039A",
> -        "EventName": "L2D_CACHE_REFILL_L3D_MISS_PRF",
> -        "BriefDescription": "This event counts L2D_CACHE_REFILL_L3D_MISS caused by prefetch access."
> -    },
> -    {
> -        "EventCode": "0x039B",
> -        "EventName": "L2D_CACHE_REFILL_L3D_MISS_HWPRF",
> -        "BriefDescription": "This event counts L2D_CACHE_REFILL_L3D_MISS caused by hardware prefetch access."
> -    },
> -    {
> -        "EventCode": "0x039C",
> -        "EventName": "L2D_CACHE_REFILL_L3D_HIT",
> -        "BriefDescription": "This event counts operations that cause a hit of the L3 cache."
> -    },
>       {
>           "EventCode": "0x039D",
>           "EventName": "L2D_CACHE_REFILL_L3D_HIT_DM",
> @@ -87,16 +67,6 @@
>           "EventName": "L2D_CACHE_REFILL_L3D_HIT_DM_WR",
>           "BriefDescription": "This event counts L2D_CACHE_REFILL_L3D_HIT caused by demand write access."
>       },
> -    {
> -        "EventCode": "0x03A0",
> -        "EventName": "L2D_CACHE_REFILL_L3D_HIT_PRF",
> -        "BriefDescription": "This event counts L2D_CACHE_REFILL_L3D_HIT caused by prefetch access."
> -    },
> -    {
> -        "EventCode": "0x03A1",
> -        "EventName": "L2D_CACHE_REFILL_L3D_HIT_HWPRF",
> -        "BriefDescription": "This event counts L2D_CACHE_REFILL_L3D_HIT caused by hardware prefetch access."
> -    },
>       {
>           "EventCode": "0x03A2",
>           "EventName": "L2D_CACHE_REFILL_L3D_MISS_PFTGT_HIT",
> @@ -151,9 +121,5 @@
>           "EventCode": "0x03AC",
>           "EventName": "L2D_CACHE_REFILL_L3D_MISS_FR_L3",
>           "BriefDescription": "This event counts the number of L3 cache misses where the requests access L3 cache in the different socket from the requests."
> -    },
> -    {
> -        "ArchStdEvent": "L3D_CACHE_LMISS_RD",
> -        "BriefDescription": "This event counts access counted by L3D_CACHE that is not completed by the L3D cache, and  a Memory-read operation, as defined by the L2D_CACHE_REFILL_L3D_MISS events."
>       }
>   ]
> diff --git a/tools/perf/pmu-events/arch/arm64/fujitsu/monaka/ll_cache.json b/tools/perf/pmu-events/arch/arm64/fujitsu/monaka/ll_cache.json
> index a441b84729ab..c2325855eda3 100644
> --- a/tools/perf/pmu-events/arch/arm64/fujitsu/monaka/ll_cache.json
> +++ b/tools/perf/pmu-events/arch/arm64/fujitsu/monaka/ll_cache.json
> @@ -2,9 +2,5 @@
>       {
>           "ArchStdEvent": "LL_CACHE_RD",
>           "BriefDescription": "This event counts access counted by L3D_CACHE that is a Memory-read operation, as defined by the L2D_CACHE_REFILL_L3D_CACHE events."
> -    },
> -    {
> -        "ArchStdEvent": "LL_CACHE_MISS_RD",
> -        "BriefDescription": "This event counts access counted by L3D_CACHE that is not completed by the L3D cache, and a Memory-read operation, as defined by the L2D_CACHE_REFILL_L3D_MISS events."
>       }
>   ]