[V2,0/5] powerpc/perf: Export processor pipeline stage cycles information

Performance Monitoring Unit (PMU) registers in powerpc exports
number of cycles elapsed between different stages in the pipeline.
Example, sampling registers in ISA v3.1.

This patchset implements kernel and perf tools support to expose
these pipeline stage cycles using the sample type PERF_SAMPLE_WEIGHT_TYPE.

Patch 1/5 adds kernel side support to store the cycle counter
values as part of 'var2_w' and 'var3_w' fields of perf_sample_weight
structure.

Patch 2/5 adds support to make the perf report column header
strings as dynamic.
Patch 3/5 adds powerpc support in perf tools for PERF_SAMPLE_WEIGHT_STRUCT
in sample type: PERF_SAMPLE_WEIGHT_TYPE.
Patch 4/5 adds support to present pipeline stage cycles as part of
mem-mode.
Patch 5/5 is to display the new sort dimenstion in perf report columns
only on powerpc.

Sample output on powerpc:

# perf mem record ls
# perf mem report

# To display the perf.data header info, please use --header/--header-only options.
#
#
# Total Lost Samples: 0
#
# Samples: 11  of event 'cpu/mem-loads/'
# Total weight : 1332
# Sort order   : local_weight,mem,sym,dso,symbol_daddr,dso_daddr,snoop,tlb,locked,blocked,local_ins_lat,stall_cyc
#
# Overhead       Samples  Local Weight  Memory access             Symbol                              Shared Object     Data Symbol                                    Data Object            Snoop         TLB access              Locked  Blocked     Finish Cyc     Dispatch Cyc 
# ........  ............  ............  ........................  ..................................  ................  .............................................  .....................  ............  ......................  ......  ..........  .............  .............
#
    44.14%             1  588           L1 hit                    [k] rcu_nmi_exit                    [kernel.vmlinux]  [k] 0xc0000007ffdd21b0                         [unknown]              N/A           N/A                     No       N/A        7              5            
    22.22%             1  296           L1 hit                    [k] copypage_power7                 [kernel.vmlinux]  [k] 0xc0000000ff6a1780                         [unknown]              N/A           N/A                     No       N/A        293            3            
     6.98%             1  93            L1 hit                    [.] _dl_addr                        libc-2.31.so      [.] 0x00007fff86fa5058                         libc-2.31.so           N/A           N/A                     No       N/A        7              1            
     6.61%             1  88            L2 hit                    [.] new_do_write                    libc-2.31.so      [.] _IO_2_1_stdout_+0x0                        libc-2.31.so           N/A           N/A                     No       N/A        84             1            
     5.93%             1  79            L1 hit                    [k] printk_nmi_exit                 [kernel.vmlinux]  [k] 0xc0000006085df6b0                         [unknown]              N/A           N/A                     No       N/A        7              1            
     4.05%             1  54            L2 hit                    [.] __alloc_dir                     libc-2.31.so      [.] 0x00007fffdb70a640                         [stack]                N/A           N/A                     No       N/A        18             1            
     3.60%             1  48            L1 hit                    [.] _init                           ls                [.] 0x000000016ca82118                         [heap]                 N/A           N/A                     No       N/A        7              6            
     2.40%             1  32            L1 hit                    [k] desc_read                       [kernel.vmlinux]  [k] _printk_rb_static_descs+0x1ea10            [kernel.vmlinux].data  N/A           N/A                     No       N/A        7              1            
     1.65%             1  22            L2 hit                    [k] perf_iterate_ctx.constprop.139  [kernel.vmlinux]  [k] 0xc00000064d79e8a8                         [unknown]              N/A           N/A                     No       N/A        16             1            
     1.58%             1  21            L1 hit                    [k] perf_event_interrupt            [kernel.vmlinux]  [k] 0xc0000006085df6b0                         [unknown]              N/A           N/A                     No       N/A        7              1            
     0.83%             1  11            L1 hit                    [k] perf_event_exec                 [kernel.vmlinux]  [k] 0xc0000007ffdd3288                         [unknown]              N/A           N/A                     No       N/A        7              4            


Changelog:
Changes from v1 -> v2
  Addressed Jiri's review comments:
  - Display the new sort dimension 'p_stage_cyc' only
    on supported architecture.
  - Check for arch specific header string for matching
    sort order in patch2.
  
Athira Rajeev (5):
  powerpc/perf: Expose processor pipeline stage cycles using
    PERF_SAMPLE_WEIGHT_STRUCT
  tools/perf: Add dynamic headers for perf report columns
  tools/perf: Add powerpc support for PERF_SAMPLE_WEIGHT_STRUCT
  tools/perf: Support pipeline stage cycles for powerpc
  tools/perf: Display sort dimension p_stage_cyc only on supported archs

 arch/powerpc/include/asm/perf_event_server.h |  2 +-
 arch/powerpc/perf/core-book3s.c              |  4 +-
 arch/powerpc/perf/isa207-common.c            | 29 ++++++++++++--
 arch/powerpc/perf/isa207-common.h            |  6 ++-
 tools/perf/Documentation/perf-report.txt     |  2 +
 tools/perf/arch/powerpc/util/Build           |  2 +
 tools/perf/arch/powerpc/util/event.c         | 53 ++++++++++++++++++++++++
 tools/perf/arch/powerpc/util/evsel.c         |  8 ++++
 tools/perf/util/event.h                      |  3 ++
 tools/perf/util/hist.c                       | 11 +++--
 tools/perf/util/hist.h                       |  1 +
 tools/perf/util/session.c                    |  4 +-
 tools/perf/util/sort.c                       | 60 +++++++++++++++++++++++++++-
 tools/perf/util/sort.h                       |  2 +
 14 files changed, 174 insertions(+), 13 deletions(-)
 create mode 100644 tools/perf/arch/powerpc/util/event.c
 create mode 100644 tools/perf/arch/powerpc/util/evsel.c

On Mon, 22 Mar 2021 10:57:22 -0400, Athira Rajeev wrote:
> Performance Monitoring Unit (PMU) registers in powerpc exports
> number of cycles elapsed between different stages in the pipeline.
> Example, sampling registers in ISA v3.1.
> 
> This patchset implements kernel and perf tools support to expose
> these pipeline stage cycles using the sample type PERF_SAMPLE_WEIGHT_TYPE.
> 
> [...]

Patch 1 applied to powerpc/next.

[1/5] powerpc/perf: Expose processor pipeline stage cycles using PERF_SAMPLE_WEIGHT_STRUCT
      https://git.kernel.org/powerpc/c/af31fd0c9107e400a8eb89d0eafb40bb78802f79

cheers