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authorAlexander Yarygin <yarygin@linux.vnet.ibm.com>2014-10-03 16:40:12 +0200
committerArnaldo Carvalho de Melo <acme@redhat.com>2014-10-15 22:39:03 +0200
commit673d659f5c5918b7ddbafebf1f129c9eb82973b4 (patch)
tree2e2abafb2a325803af41de4f50a399c06c270c7a /tools/perf
parentperf session: Add option to copy events when queueing (diff)
downloadlinux-673d659f5c5918b7ddbafebf1f129c9eb82973b4.tar.xz
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perf kvm stat live: Enable events copying
Process of analyzing events caused by 2 functions: mmap_read() and finished_round(). During mmap_read(), perf receives events from shared memory, queues their pointers for further processing in finished_round() and notifies the kernel that the events have been processed. By the time when finished_round() is invoked, queued events can be overwritten by the kernel, so the finished_round() occurs on potentially corrupted memory. Since there is no place where the event can be safely consumed, let's copy events when queueing. Signed-off-by: Alexander Yarygin <yarygin@linux.vnet.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Namhyung Kim <namhyung.kim@lge.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/r/1412347212-28237-3-git-send-email-yarygin@linux.vnet.ibm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf')
-rw-r--r--tools/perf/builtin-kvm.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/tools/perf/builtin-kvm.c b/tools/perf/builtin-kvm.c
index ef9fc15fbfbf..b65eb0507b38 100644
--- a/tools/perf/builtin-kvm.c
+++ b/tools/perf/builtin-kvm.c
@@ -1358,6 +1358,7 @@ static int kvm_events_live(struct perf_kvm_stat *kvm,
}
kvm->session->evlist = kvm->evlist;
perf_session__set_id_hdr_size(kvm->session);
+ ordered_events__set_copy_on_queue(&kvm->session->ordered_events, true);
machine__synthesize_threads(&kvm->session->machines.host, &kvm->opts.target,
kvm->evlist->threads, false);
err = kvm_live_open_events(kvm);