Messages in this thread Patch in this message | | | From | Alexander Yarygin <> | Subject | [PATCH 2/2] perf kvm stat live: Enable events copying | Date | Thu, 18 Sep 2014 21:07:39 +0400 |
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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.
Let's copy events when queueing.
Signed-off-by: Alexander Yarygin <yarygin@linux.vnet.ibm.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: David Ahern <dsahern@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> --- tools/perf/builtin-kvm.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/tools/perf/builtin-kvm.c b/tools/perf/builtin-kvm.c index f5d3ae4..c5b6d1d 100644 --- a/tools/perf/builtin-kvm.c +++ b/tools/perf/builtin-kvm.c @@ -1369,6 +1369,7 @@ static int kvm_events_live(struct perf_kvm_stat *kvm, goto out; } kvm->session->evlist = kvm->evlist; + kvm->session->copy_on_queue = true; perf_session__set_id_hdr_size(kvm->session); machine__synthesize_threads(&kvm->session->machines.host, &kvm->opts.target, kvm->evlist->threads, false); -- 1.9.1
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