Re: [PATCH v3 00/11] perf c2c: Support display for Arm64
From: Arnaldo Carvalho de Melo
Date: Mon May 23 2022 - 08:43:21 EST
Em Mon, May 23, 2022 at 10:43:47AM +0200, Jiri Olsa escreveu:
> On Wed, May 18, 2022 at 01:57:18PM +0800, Leo Yan wrote:
> > Arm64 Neoverse CPUs supports data source in Arm SPE trace, this allows
> > us to detect cache line contention and transfers.
> >
> > Unlike x86 architecture, Arm SPE trace data cannot provide 'HITM'
> > snooping flag, Ali Said has a patch set v9 "perf: arm-spe: Decode SPE
> > source and use for perf c2c" [1] which introduces 'peer' flag and
> > synthesizes memory samples with this flag.
> >
> > Based on patch set [1], this patch set is to finish the second half work
> > to consume the 'peer' flag in perf c2c tool, it adds an extra display
> > 'peer' mode.
Ok, I'll look at the base patch set...
> > Patches 01, 02 and 03 are to support 'N/A' metrics for store operations.
> >
> > Patches 04 and 05 adds statistics and dimensions for memory samples with
> > peer flag.
> >
> > Patches 06, 07, 08 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 09, 10 and 11 are to extend display 'peer' mode, it also updates
> > the document and also changes to use 'peer' mode as default mode on
> > Arm64 arches.
> >
> > This patch set has been verified for both x86 and Arm64 memory samples.
> >
> > The display result with x86 memory samples:
> >
> > =================================================
> > Shared Data Cache Line Table
> > =================================================
> > #
> > # ----------- Cacheline ---------- Tot ------- Load Hitm ------- Snoop Total Total Total --------- Stores -------- ----- Core Load Hit ----- - LLC Load Hit -- - RMT Load Hit -- --- Load Dram ----
> > # Index Address Node PA cnt Hitm Total LclHitm RmtHitm Peer 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 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 0 914 914 0 0 0 0 272 374 52 87 129 0 0 0 0
> >
> > =================================================
> > Shared Cache Line Distribution Pareto
> > =================================================
> > #
> > # ----- HITM ----- Snoop ------- Store Refs ------ --------- Data address --------- --------------- cycles --------------- Total cpu Shared
> > # Num RmtHitm LclHitm Peer L1 Hit L1 Miss N/A Offset Node PA cnt Code address rmt hitm lcl hitm load peer records cnt Symbol Object Source:Line Node
> > # ..... ....... ....... ....... ....... ....... ....... .................. .... ...... .................. ........ ........ ........ ........ ....... ........ ...................... ................. ....................... ....
> > #
> > -------------------------------------------------------------------------------
> > 0 0 252 0 2024 470 0 0x55c8971f0080
> > -------------------------------------------------------------------------------
> > 0.00% 12.30% 0.00% 0.00% 0.00% 0.00% 0x0 0 1 0x55c8971ed3e9 0 1313 863 0 1222 3 [.] 0x00000000000013e9 false_sharing.exe false_sharing.exe[13e9] 0
> > 0.00% 0.79% 0.00% 90.51% 0.00% 0.00% 0x0 0 1 0x55c8971ed3e2 0 1800 878 0 3029 3 [.] 0x00000000000013e2 false_sharing.exe false_sharing.exe[13e2] 0
> > 0.00% 0.00% 0.00% 9.49% 100.00% 0.00% 0x0 0 1 0x55c8971ed3f4 0 0 0 0 662 3 [.] 0x00000000000013f4 false_sharing.exe false_sharing.exe[13f4] 0
> > 0.00% 86.90% 0.00% 0.00% 0.00% 0.00% 0x20 0 1 0x55c8971ed447 0 141 103 0 1131 2 [.] 0x0000000000001447 false_sharing.exe false_sharing.exe[1447] 0
> >
> > -------------------------------------------------------------------------------
> > 1 0 129 0 0 0 0 0x55c8971f00c0
> > -------------------------------------------------------------------------------
> > 0.00% 100.00% 0.00% 0.00% 0.00% 0.00% 0x20 0 1 0x55c8971ed455 0 88 94 0 914 2 [.] 0x0000000000001455 false_sharing.exe false_sharing.exe[1455] 0
> >
> >
> > The display result with Arm SPE memory samples:
> >
> > =================================================
> > Shared Data Cache Line Table
> > =================================================
> > #
> > # ----------- Cacheline ---------- Snoop ------- Load Hitm ------- Snoop Total Total Total --------- Stores -------- ----- Core Load Hit ----- - LLC Load Hit -- - RMT Load Hit -- --- Load Dram ----
> > # Index Address Node PA cnt Peer Total LclHitm RmtHitm Peer records Loads Stores L1Hit L1Miss N/A FB L1 L2 LclHit LclHitm RmtHit RmtHitm Lcl Rmt
> > # ..... .................. .... ...... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ........ ....... ........ ....... ........ ........
> > #
> > 0 0xaaaac17d6000 N/A 0 100.00% 0 0 0 99 18851 18851 0 0 0 0 0 18752 0 99 0 0 0 0 0
> >
> > =================================================
> > Shared Cache Line Distribution Pareto
> > =================================================
> > #
> > # ----- HITM ----- Snoop ------- Store Refs ------ --------- Data address --------- --------------- cycles --------------- Total cpu Shared
> > # Num RmtHitm LclHitm Peer L1 Hit L1 Miss N/A Offset Node PA cnt Code address rmt hitm lcl hitm load peer records cnt Symbol Object Source:Line Node
> > # ..... ....... ....... ....... ....... ....... ....... .................. .... ...... .................. ........ ........ ........ ........ ....... ........ ...................... ................ ............... ....
> > #
> > -------------------------------------------------------------------------------
> > 0 0 0 99 0 0 0 0xaaaac17d6000
> > -------------------------------------------------------------------------------
> > 0.00% 0.00% 6.06% 0.00% 0.00% 0.00% 0x20 N/A 0 0xaaaac17c25ac 0 0 43 375 18469 2 [.] 0x00000000000025ac memstress memstress[25ac] 0
> > 0.00% 0.00% 93.94% 0.00% 0.00% 0.00% 0x29 N/A 0 0xaaaac17c3e88 0 0 173 180 135 2 [.] 0x0000000000003e88 memstress memstress[3e88] 0
> >
> > [1] https://lore.kernel.org/lkml/20220517020326.18580-1-alisaidi@xxxxxxxxxx/
> >
> > 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).
>
> LGTM
>
> Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>
>
> thanks,
> jirka
>
> >
> > 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.
> >
> >
> > Leo Yan (11):
> > perf mem: Add stats for store operation with no available memory level
> > perf c2c: Add dimensions for 'N/A' metrics of store operation
> > perf c2c: Update documentation for store metric 'N/A'
> > perf mem: Add statistics for peer snooping
> > perf c2c: Add dimensions for peer load 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: Sort on peer snooping for load operations
> > perf c2c: Update documentation for new display option 'peer'
> > perf c2c: Use 'peer' as default display for Arm64
> >
> > tools/perf/Documentation/perf-c2c.txt | 34 ++-
> > tools/perf/builtin-c2c.c | 357 ++++++++++++++++++++------
> > tools/perf/util/mem-events.c | 25 +-
> > tools/perf/util/mem-events.h | 2 +
> > 4 files changed, 331 insertions(+), 87 deletions(-)
> >
> > --
> > 2.25.1
> >
--
- Arnaldo