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Message-ID: <Ypph9lA1qavXXZI5@kernel.org>
Date: Fri, 3 Jun 2022 21:33:10 +0200
From: Arnaldo Carvalho de Melo <acme@...nel.org>
To: Leo Yan <leo.yan@...aro.org>
Cc: Peter Zijlstra <peterz@...radead.org>,
Ingo Molnar <mingo@...hat.com>,
Mark Rutland <mark.rutland@....com>,
Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
Jiri Olsa <jolsa@...nel.org>,
Namhyung Kim <namhyung@...nel.org>, Alyssa Ross <hi@...ssa.is>,
Ian Rogers <irogers@...gle.com>, Like Xu <likexu@...cent.com>,
Kajol Jain <kjain@...ux.ibm.com>,
Li Huafei <lihuafei1@...wei.com>,
Joe Mario <jmario@...hat.com>,
Adam Li <adam.li@...erecomputing.com>,
German Gomez <german.gomez@....com>,
James Clark <james.clark@....com>,
Ali Saidi <alisaidi@...zon.com>,
linux-perf-users@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v4 00/12] perf c2c: Support display for Arm64
Em Mon, May 30, 2022 at 07:40:24PM +0800, Leo Yan escreveu:
> Arm64 Neoverse CPUs supports data source in Arm SPE trace, this allows
> us to detect cache line contention and transfers.
>
> This patch set is based on Ali Said's patch set v9 "perf: arm-spe: Decode SPE
> source and use for perf c2c" [1] and Ali's patch set doesn't need any
> change in this new round.
IIRC there is a kernel part there, please let me know when that part
gets merged so that I can process this 12 patches long set.
- Arnaldo
> To clearly show peer loads and express the local peer loads and remote
> peer lodes, this patch introduces three new metrics 'lcl_peer',
> 'rmt_peer' and 'tot_peer'. The display 'peer' mode uses metric
> 'tot_peer' for sorting cache lines.
>
> Patches 01-05 adds statistics for memory samples, and add dimensions for
> peer metrics.
>
> Patches 06-09 are for refactoring, it refines the code with more general
> naming so this can allow us to easier to extend display modes but not
> strictly bound to HITM tags.
>
> Patches 10-11 are to extend display 'peer' mode, and also changes to use
> 'peer' mode as default mode for Arm64 arches.
>
> Patch 12 updates document to describe the new dimensions for peer
> metrics.
>
> This patch set has been verified for both x86 and Arm64 memory samples.
>
> Known issues: Joe reminded there have an issue in patch set v3 that the
> cache line metric shows 'N/A' for node, this is because Arm SPE trace
> data doesn't contain physical address and leads to perf c2c tool fails
> to find matched node range if physical address is zero. This issue is
> addressed in a separte patch [2]. Since I am still using the old
> perf data file (I have no Neoverse platforms), the output result still
> shows the Node field is 'N/A'.
>
> Another thing is we need to enhance data source setting for old Arm
> platforms. As discussed, German would follow up this task later.
>
> The latest patch set has been uploaded on the git server [3].
>
> The display result with x86 memory samples:
>
> =================================================
> Shared Data Cache Line Table
> =================================================
> #
> # ----------- Cacheline ---------- Tot ------- Load Hitm ------- Total Total Total --------- Stores -------- ----- Core Load Hit ----- - LLC Load Hit -- - RMT Load Hit -- --- Load Dram ----
> # Index Address Node PA cnt Hitm Total LclHitm RmtHitm records Loads Stores L1Hit L1Miss N/A FB L1 L2 LclHit LclHitm RmtHit RmtHitm Lcl Rmt
> # ..... .................. .... ...... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ........ ....... ........ ....... ........ ........
> #
> 0 0x55c8971f0080 0 1967 66.14% 252 252 0 6044 3550 2494 2024 470 0 528 2672 78 20 252 0 0 0 0
> 1 0x55c8971f00c0 0 1 33.86% 129 129 0 914 914 0 0 0 0 272 374 52 87 129 0 0 0 0
>
> =================================================
> Shared Cache Line Distribution Pareto
> =================================================
> #
> # ----- HITM ----- ------- Store Refs ------ --------- Data address --------- ---------- cycles ---------- Total cpu Shared
> # Num RmtHitm LclHitm L1 Hit L1 Miss N/A Offset Node PA cnt Code address rmt hitm lcl hitm load records cnt Symbol Object Source:Line Node
> # ..... ....... ....... ....... ....... ....... .................. .... ...... .................. ........ ........ ........ ....... ........ ...................... ................. ....................... ....
> #
> ----------------------------------------------------------------------
> 0 0 252 2024 470 0 0x55c8971f0080
> ----------------------------------------------------------------------
> 0.00% 12.30% 0.00% 0.00% 0.00% 0x0 0 1 0x55c8971ed3e9 0 1313 863 1222 3 [.] 0x00000000000013e9 false_sharing.exe false_sharing.exe[13e9] 0
> 0.00% 0.79% 90.51% 0.00% 0.00% 0x0 0 1 0x55c8971ed3e2 0 1800 878 3029 3 [.] 0x00000000000013e2 false_sharing.exe false_sharing.exe[13e2] 0
> 0.00% 0.00% 9.49% 100.00% 0.00% 0x0 0 1 0x55c8971ed3f4 0 0 0 662 3 [.] 0x00000000000013f4 false_sharing.exe false_sharing.exe[13f4] 0
> 0.00% 86.90% 0.00% 0.00% 0.00% 0x20 0 1 0x55c8971ed447 0 141 103 1131 2 [.] 0x0000000000001447 false_sharing.exe false_sharing.exe[1447] 0
>
> ----------------------------------------------------------------------
> 1 0 129 0 0 0 0x55c8971f00c0
> ----------------------------------------------------------------------
> 0.00% 100.00% 0.00% 0.00% 0.00% 0x20 0 1 0x55c8971ed455 0 88 94 914 2 [.] 0x0000000000001455 false_sharing.exe false_sharing.exe[1455] 0
>
>
> The display result with Arm SPE:
>
> =================================================
> Shared Data Cache Line Table
> =================================================
> #
> # ----------- Cacheline ---------- Peer ------- Load Peer ------- Total Total Total --------- Stores -------- ----- Core Load Hit ----- - LLC Load Hit -- - RMT Load Hit -- --- Load Dram ----
> # Index Address Node PA cnt Snoop Total Local Remote records Loads Stores L1Hit L1Miss N/A FB L1 L2 LclHit LclHitm RmtHit RmtHitm Lcl Rmt
> # ..... .................. .... ...... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ........ ....... ........ ....... ........ ........
> #
> 0 0xaaaac17d6000 N/A 0 100.00% 99 99 0 18851 18851 0 0 0 0 0 18752 0 99 0 0 0 0 0
>
> =================================================
> Shared Cache Line Distribution Pareto
> =================================================
> #
> # -- Peer Snoop -- ------- Store Refs ------ --------- Data address --------- ---------- cycles ---------- Total cpu Shared
> # Num Rmt Lcl L1 Hit L1 Miss N/A Offset Node PA cnt Code address rmt peer lcl peer load records cnt Symbol Object Source:Line Node{cpus %peers %stores}
> # ..... ....... ....... ....... ....... ....... .................. .... ...... .................. ........ ........ ........ ....... ........ ...................... ................ ............... ....
> #
> ----------------------------------------------------------------------
> 0 0 99 0 0 0 0xaaaac17d6000
> ----------------------------------------------------------------------
> 0.00% 6.06% 0.00% 0.00% 0.00% 0x20 N/A 0 0xaaaac17c25ac 0 375 43 18469 2 [.] 0x00000000000025ac memstress memstress[25ac] 0{ 2 100.0% n/a}
> 0.00% 93.94% 0.00% 0.00% 0.00% 0x29 N/A 0 0xaaaac17c3e88 0 180 173 135 2 [.] 0x0000000000003e88 memstress memstress[3e88] 0{ 2 100.0% n/a}
>
>
> Changes from v3:
> * Changed to display remote and local peer accesses (Joe);
> * Fixed the usage info for display types (Joe);
> * Do not display HITM dimensions when use 'peer' display, and HITM
> display doesn't show any 'peer' dimensions (James);
> * Split to smaller patches for adding dimensions of peer operations;
> * Updated documentation to reflect the latest GUI and stdio.
>
> Changes from v2:
> * Updated patch 04 to account metrics for both cache level and ld_peer
> for PEER flag;
> * Updated document for metric 'rmt_hit' which is accounted for all
> remote accesses (include remote DRAM and any upward caches).
>
> Changes from v1:
> * Updated patches 01, 02 and 03 to support 'N/A' metrics for store
> operations, so can align with the patch set [1] for store samples.
>
>
> [1] https://lore.kernel.org/lkml/20220517020326.18580-1-alisaidi@amazon.com/
> [2] https://lore.kernel.org/lkml/20220530083645.253432-1-leo.yan@linaro.org/
> [3] https://git.linaro.org/people/leo.yan/linux-spe.git/ branch: perf_c2c_arm_spe_peer_v4
>
>
> Leo Yan (12):
> perf mem: Add statistics for peer snooping
> perf c2c: Output statistics for peer snooping
> perf c2c: Add dimensions for peer load operations
> perf c2c: Add dimensions of peer metrics for cache line view
> perf c2c: Add mean dimensions for peer operations
> perf c2c: Use explicit names for display macros
> perf c2c: Rename dimension from 'percent_hitm' to
> 'percent_costly_snoop'
> perf c2c: Refactor node header
> perf c2c: Refactor display string
> perf c2c: Sort on peer snooping for load operations
> perf c2c: Use 'peer' as default display for Arm64
> perf c2c: Update documentation for new display option 'peer'
>
> tools/perf/Documentation/perf-c2c.txt | 30 +-
> tools/perf/builtin-c2c.c | 454 ++++++++++++++++++++------
> tools/perf/util/mem-events.c | 28 +-
> tools/perf/util/mem-events.h | 3 +
> 4 files changed, 403 insertions(+), 112 deletions(-)
>
> --
> 2.25.1
--
- Arnaldo
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