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  1. 21 3月, 2018 24 次提交
  3. 05 3月, 2018 3 次提交
  5. 17 2月, 2018 1 次提交
    • J
      perf report: Fix wrong jump arrow · b40982e8
      由 Jin Yao 提交于 
      When we use perf report interactive annotate view, we can see
the position of jump arrow is not correct. For example,

1. perf record -b ...
2. perf report
3. In interactive mode, select Annotate 'function'

Percent│ IPC Cycle
       │                                if (flag)
  1.37 │0.4┌──   1      ↓ je     82
       │   │                                    x += x / y + y / x;
  0.00 │0.4│  1310        movsd  (%rsp),%xmm0
  0.00 │0.4│   565        movsd  0x8(%rsp),%xmm4
       │0.4│              movsd  0x8(%rsp),%xmm1
       │0.4│              movsd  (%rsp),%xmm3
       │0.4│              divsd  %xmm4,%xmm0
  0.00 │0.4│   579        divsd  %xmm3,%xmm1
       │0.4│              movsd  (%rsp),%xmm2
       │0.4│              addsd  %xmm1,%xmm0
       │0.4│              addsd  %xmm2,%xmm0
  0.00 │0.4│              movsd  %xmm0,(%rsp)
       │   │                    volatile double x = 1212121212, y = 121212;
       │   │
       │   │                    s_randseed = time(0);
       │   │                    srand(s_randseed);
       │   │
       │   │                    for (i = 0; i < 2000000000; i++) {
  1.37 │0.4└─→      82:   sub    $0x1,%ebx
 28.21 │0.48    17      ↑ jne    38

The jump arrow in above example is not correct. It should add the
width of IPC and Cycle.

With this patch, the result is:

Percent│ IPC Cycle
       │                                if (flag)
  1.37 │0.48     1     ┌──je     82
       │               │                        x += x / y + y / x;
  0.00 │0.48  1310     │  movsd  (%rsp),%xmm0
  0.00 │0.48   565     │  movsd  0x8(%rsp),%xmm4
       │0.48           │  movsd  0x8(%rsp),%xmm1
       │0.48           │  movsd  (%rsp),%xmm3
       │0.48           │  divsd  %xmm4,%xmm0
  0.00 │0.48   579     │  divsd  %xmm3,%xmm1
       │0.48           │  movsd  (%rsp),%xmm2
       │0.48           │  addsd  %xmm1,%xmm0
       │0.48           │  addsd  %xmm2,%xmm0
  0.00 │0.48           │  movsd  %xmm0,(%rsp)
       │               │        volatile double x = 1212121212, y = 121212;
       │               │
       │               │        s_randseed = time(0);
       │               │        srand(s_randseed);
       │               │
       │               │        for (i = 0; i < 2000000000; i++) {
  1.37 │0.48        82:└─→sub    $0x1,%ebx
 28.21 │0.48    17      ↑ jne    38

Committer notes:

Please note that only from LBRv5 (according to Jiri) onwards, i.e. >=
Skylake is that we'll have the cycles counts in each branch record
entry, so to see the Cycles and IPC columns, and be able to test this
patch, one need a capable hardware.

While applying this I first tested it on a Broadwell class machine and
couldn't get those columns, will add code to the annotate browser to
warn the user about that, i.e. you have branch records, but no cycles,
use a more recent hardware to get the cycles and IPC columns.
Signed-off-by: NJin Yao <yao.jin@linux.intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1517223473-14750-1-git-send-email-yao.jin@linux.intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      b40982e8
  7. 27 12月, 2017 1 次提交
  9. 17 11月, 2017 11 次提交