Em Thu, Oct 15, 2020 at 03:50:33PM +0100, Leo Yan escreveu: > If the memory event doesn't contain HITM tag (like Arm SPE), it cannot > rely on HITM display to report cache false sharing. Alternatively, we > can use the LLC access and multi-threads info to locate the potential > false sharing's data address, and if we connect with source code and > analyze the multi-threads' execution timing, if can conclude load and > store the same cache line at the meantime, thus this can be helpful for > resolve the cache false sharing issue. > > This patch set is to enable the display with sorting on LLC load > accesses; it adds dimensions for total LLC hit and LLC load accesses, > and these dimensions are used for shared cache line table and pareto. > > This patch set is dependend on the patch set "perf c2c: Refine the > organization of metrics" [1]. > > [1] https://lore.kernel.org/patchwork/cover/1321499/
Ok, that one is applied and will appear publicly as soon as it goes thru my usual set of build tests. - Arnaldo > With this patch set, we can get display 'llc' as follows: > > # perf c2c report -d llc --coalesce tid,pid,iaddr,dso --stdio > > [...] > > ================================================= > Shared Data Cache Line Table > ================================================= > # > # ----------- Cacheline ---------- LLC Hit LLC Hit Total > Total Total ---- Stores ---- ----- Core Load Hit ----- - LLC Load Hit > -- - RMT Load Hit -- --- Load Dram ---- > # Index Address Node PA cnt Pct Total records > Loads Stores L1Hit L1Miss FB L1 L2 LclHit > LclHitm RmtHit RmtHitm Lcl Rmt > # ..... .................. .... ...... ....... ........ ....... > ....... ....... ....... ....... ....... ....... ....... ........ > ....... ........ ....... ........ ........ > # > 0 0x563b01e83100 0 1401 65.32% 648 7011 > 3738 3273 2582 691 515 2516 59 143 505 > 0 0 0 0 > 1 0x563b01e830c0 0 1 26.51% 263 400 > 400 0 0 0 130 3 4 262 1 > 0 0 0 0 > 2 0x563b01e83080 0 1 7.76% 77 650 > 650 0 0 0 180 348 45 14 63 > 0 0 0 0 > 3 0xffff88c3d74e82c0 0 1 0.10% 1 1 > 1 0 0 0 0 0 0 1 0 > 0 0 0 0 > 4 0xffffa587c11e38c0 N/A 0 0.10% 1 2 > 1 1 1 0 0 0 0 1 0 > 0 0 0 0 > 5 0xffffffffbd5e6fc0 0 1 0.10% 1 1 > 1 0 0 0 0 0 0 0 1 > 0 0 0 0 > 6 0x7f90a4d6c2c0 0 1 0.10% 1 1 > 1 0 0 0 0 0 0 1 0 > 0 0 0 0 > > ================================================= > Shared Cache Line Distribution Pareto > ================================================= > # > # ---- LLC LD ---- -- Store Refs -- --------- Data address > --------- ---------- cycles > ---------- Total cpu Shared > # Num LclHit LclHitm L1 Hit L1 Miss Offset Node PA > cnt Pid Tid Code address rmt hitm lcl hitm > load records cnt Symbol Object > Source:Line Node > # ..... ....... ....... ....... ....... .................. .... > ...... ....... .................. .................. ........ ........ > ........ ....... ........ ................... ................. > ........................... .... > # > ------------------------------------------------------------- > 0 143 505 2582 691 0x563b01e83100 > ------------------------------------------------------------- > 96.50% 7.72% 46.79% 0.00% 0x0 0 > 1 14100 14102:lock_th 0x563b01c81c16 0 1949 > 1331 1876 1 [.] read_write_func false_sharing.exe > false_sharing_example.c:145 0 > 0.00% 35.05% 0.00% 0.00% 0x0 0 > 1 14100 14102:lock_th 0x563b01c81c1d 0 2651 > 975 748 1 [.] read_write_func false_sharing.exe > false_sharing_example.c:146 0 > 0.00% 30.89% 0.00% 0.00% 0x0 0 > 1 14100 14103:lock_th 0x563b01c81c1d 0 1425 > 1003 762 1 [.] read_write_func false_sharing.exe > false_sharing_example.c:146 0 > 2.10% 7.52% 49.19% 0.00% 0x0 0 > 1 14100 14103:lock_th 0x563b01c81c16 0 1585 > 1053 2037 1 [.] read_write_func false_sharing.exe > false_sharing_example.c:145 0 > 0.00% 0.00% 2.52% 44.86% 0x0 0 > 1 14100 14102:lock_th 0x563b01c81c28 0 0 > 0 375 1 [.] read_write_func false_sharing.exe > false_sharing_example.c:146 0 > 0.00% 0.00% 1.51% 55.14% 0x0 0 > 1 14100 14103:lock_th 0x563b01c81c28 0 0 > 0 420 1 [.] read_write_func false_sharing.exe > false_sharing_example.c:146 0 > 1.40% 12.87% 0.00% 0.00% 0x20 0 > 1 14100 14104:reader_thd 0x563b01c81c73 0 166 > 99 417 1 [.] read_write_func false_sharing.exe > false_sharing_example.c:155 0 > 0.00% 5.94% 0.00% 0.00% 0x20 0 > 1 14100 14105:reader_thd 0x563b01c81c73 0 144 > 85 376 1 [.] read_write_func false_sharing.exe > false_sharing_example.c:155 0 > > [...] > > > Leo Yan (8): > perf mem: Add structure field c2c_stats::tot_llchit > perf c2c: Add dimensions for total LLC hit > perf c2c: Add dimensions for LLC load hit > perf c2c: Change to general naming for macros > perf c2c: Rename for shared cache line stats > perf c2c: Refactor hist entry validation > perf c2c: Add option '-d llc' for sorting with LLC load > perf c2c: Update documentation for display option 'llc' > > tools/perf/Documentation/perf-c2c.txt | 18 +- > tools/perf/builtin-c2c.c | 333 +++++++++++++++++++++----- > tools/perf/util/mem-events.c | 3 + > tools/perf/util/mem-events.h | 1 + > 4 files changed, 286 insertions(+), 69 deletions(-) > > -- > 2.17.1 > -- - Arnaldo
