pending-5.1/tools-kvm_stat-fix-fields-filter-for-child-events.patch

   1 From fb979946f7556bc5f8ddec9cdb94e8269c6a1895 Mon Sep 17 00:00:00 2001
   2 From: Stefan Raspl <stefan.raspl@de.ibm.com>
   3 Date: Sun, 21 Apr 2019 15:26:24 +0200
   4 Subject: tools/kvm_stat: fix fields filter for child events
   5
   6 [ Upstream commit 883d25e70b2f699fed9017e509d1ef8e36229b89 ]
   7
   8 The fields filter would not work with child fields, as the respective
   9 parents would not be included. No parents displayed == no childs displayed.
  10 To reproduce, run on s390 (would work on other platforms, too, but would
  11 require a different filter name):
  12 - Run 'kvm_stat -d'
  13 - Press 'f'
  14 - Enter 'instruct'
  15 Notice that events like instruction_diag_44 or instruction_diag_500 are not
  16 displayed - the output remains empty.
  17 With this patch, we will filter by matching events and their parents.
  18 However, consider the following example where we filter by
  19 instruction_diag_44:
  20
  21   kvm statistics - summary
  22                    regex filter: instruction_diag_44
  23    Event                                         Total %Total CurAvg/s
  24    exit_instruction                                276  100.0       12
  25      instruction_diag_44                           256   92.8       11
  26    Total                                           276              12
  27
  28 Note that the parent ('exit_instruction') displays the total events, but
  29 the childs listed do not match its total (256 instead of 276). This is
  30 intended (since we're filtering all but one child), but might be confusing
  31 on first sight.
  32
  33 Signed-off-by: Stefan Raspl <raspl@linux.ibm.com>
  34 Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
  35 Signed-off-by: Sasha Levin <sashal@kernel.org>
  36 ---
  37  tools/kvm/kvm_stat/kvm_stat     | 16 ++++++++++++----
  38  tools/kvm/kvm_stat/kvm_stat.txt |  2 ++
  39  2 files changed, 14 insertions(+), 4 deletions(-)
  40
  41 diff --git a/tools/kvm/kvm_stat/kvm_stat b/tools/kvm/kvm_stat/kvm_stat
  42 index 2ed395b817cb..bc508dae286c 100755
  43 --- a/tools/kvm/kvm_stat/kvm_stat
  44 +++ b/tools/kvm/kvm_stat/kvm_stat
  45 @@ -575,8 +575,12 @@ class TracepointProvider(Provider):
  46      def update_fields(self, fields_filter):
  47          """Refresh fields, applying fields_filter"""
  48          self.fields = [field for field in self._get_available_fields()
  49 -                       if self.is_field_wanted(fields_filter, field) or
  50 -                       ARCH.tracepoint_is_child(field)]
  51 +                       if self.is_field_wanted(fields_filter, field)]
  52 +        # add parents for child fields - otherwise we won't see any output!
  53 +        for field in self._fields:
  54 +            parent = ARCH.tracepoint_is_child(field)
  55 +            if (parent and parent not in self._fields):
  56 +                self.fields.append(parent)
  57
  58      @staticmethod
  59      def _get_online_cpus():
  60 @@ -735,8 +739,12 @@ class DebugfsProvider(Provider):
  61      def update_fields(self, fields_filter):
  62          """Refresh fields, applying fields_filter"""
  63          self._fields = [field for field in self._get_available_fields()
  64 -                        if self.is_field_wanted(fields_filter, field) or
  65 -                        ARCH.debugfs_is_child(field)]
  66 +                        if self.is_field_wanted(fields_filter, field)]
  67 +        # add parents for child fields - otherwise we won't see any output!
  68 +        for field in self._fields:
  69 +            parent = ARCH.debugfs_is_child(field)
  70 +            if (parent and parent not in self._fields):
  71 +                self.fields.append(parent)
  72
  73      @property
  74      def fields(self):
  75 diff --git a/tools/kvm/kvm_stat/kvm_stat.txt b/tools/kvm/kvm_stat/kvm_stat.txt
  76 index 0811d860fe75..c057ba52364e 100644
  77 --- a/tools/kvm/kvm_stat/kvm_stat.txt
  78 +++ b/tools/kvm/kvm_stat/kvm_stat.txt
  79 @@ -34,6 +34,8 @@ INTERACTIVE COMMANDS
  80  *c*::  clear filter
  81
  82  *f*::  filter by regular expression
  83 + ::     *Note*: Child events pull in their parents, and parents' stats summarize
  84 +                all child events, not just the filtered ones
  85
  86  *g*::  filter by guest name/PID
  87
  88 --
  89 2.20.1
  90