From 673d659f5c5918b7ddbafebf1f129c9eb82973b4 Mon Sep 17 00:00:00 2001 From: Alexander Yarygin <yarygin@linux.vnet.ibm.com> Date: Fri, 3 Oct 2014 18:40:12 +0400 Subject: 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> --- tools/perf/builtin-kvm.c | 1 + 1 file changed, 1 insertion(+) (limited to 'tools/perf') diff --git a/tools/perf/builtin-kvm.c b/tools/perf/builtin-kvm.c index ef9fc15..b65eb050 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); -- cgit v1.1