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author | David Ahern <dsahern@gmail.com> | 2012-07-20 17:25:49 -0600 |
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committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2012-07-25 11:30:13 -0300 |
commit | adb5d2a487c55e5ca2ecc0b73c8f592e95d292c7 (patch) | |
tree | 7d479665da86eb90560e6838a8e6536e99b8fdba /tools/perf/util/session.c | |
parent | 7c0f4a4113ba5de7898c246eeaeee4c23d94b887 (diff) | |
download | op-kernel-dev-adb5d2a487c55e5ca2ecc0b73c8f592e95d292c7.zip op-kernel-dev-adb5d2a487c55e5ca2ecc0b73c8f592e95d292c7.tar.gz |
perf kvm: Fix bug resolving guest kernel syms
Guest kernel symbols are not resolved despite passing the information
needed to resolve them. e.g.,
perf kvm --guest --guestmount=/tmp/guest-mount record -a -- sleep 1
perf kvm --guest --guestmount=/tmp/guest-mount report --stdio
36.55% [guest/11399] [unknown] [g] 0xffffffff81600bc8
33.19% [guest/10474] [unknown] [g] 0x00000000c0116e00
30.26% [guest/11094] [unknown] [g] 0xffffffff8100a288
43.69% [guest/10474] [unknown] [g] 0x00000000c0103d90
37.38% [guest/11399] [unknown] [g] 0xffffffff81600bc8
12.24% [guest/11094] [unknown] [g] 0xffffffff810aa91d
6.69% [guest/11094] [unknown] [u] 0x00007fa784d721c3
which is just pathetic.
After a maddening 2 days sifting through perf minutia I found it --
id_hdr_size is not initialized for guest machines. This shows up on the
report side as random garbage for the cpu and timestamp, e.g.,
29816 7310572949125804849 0x1ac0 [0x50]: PERF_RECORD_MMAP ...
That messes up the sample sorting such that synthesized guest maps are
processed last.
With this patch you get a much more helpful report:
12.11% [guest/11399] [guest.kernel.kallsyms.11399] [g] irqtime_account_process_tick
10.58% [guest/11399] [guest.kernel.kallsyms.11399] [g] run_timer_softirq
6.95% [guest/11094] [guest.kernel.kallsyms.11094] [g] printk_needs_cpu
6.50% [guest/11094] [guest.kernel.kallsyms.11094] [g] do_timer
6.45% [guest/11399] [guest.kernel.kallsyms.11399] [g] idle_balance
4.90% [guest/11094] [guest.kernel.kallsyms.11094] [g] native_read_tsc
...
v2:
- changed rbtree walk to use rb_first per Namhyung's suggestion
Tested-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1342826756-64663-5-git-send-email-dsahern@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/util/session.c')
-rw-r--r-- | tools/perf/util/session.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c index 90ee39d..8e4f075 100644 --- a/tools/perf/util/session.c +++ b/tools/perf/util/session.c @@ -87,6 +87,7 @@ void perf_session__update_sample_type(struct perf_session *self) self->sample_id_all = perf_evlist__sample_id_all(self->evlist); self->id_hdr_size = perf_evlist__id_hdr_size(self->evlist); self->host_machine.id_hdr_size = self->id_hdr_size; + machines__set_id_hdr_size(&self->machines, self->id_hdr_size); } int perf_session__create_kernel_maps(struct perf_session *self) |