On Tue, 11 May 2021 16:25:35 +0300 Yordan Karadzhov <y.karadz@xxxxxxxxx> wrote: > > You can reproduce this with: > > > > http://rostedt.org/private/trace-no-map.tar.bz2 > > > > diff --git a/src/KsPlotTools.cpp b/src/KsPlotTools.cpp > > index 225dc34..abef5f8 100644 > > --- a/src/KsPlotTools.cpp > > +++ b/src/KsPlotTools.cpp > > @@ -1280,7 +1280,7 @@ void Graph::fillTaskGraph(int sd, int pid) > > false, > > _collectionPtr, > > &index); > > I wonder why this fails? Is it because "pid" is negative? The fix below > is appropriate, however we should detect negative PIDs and abort > plotting much earlier. I believe the issue is that we failed to map which host task goes with which guest vCPUU, and just randomly picked one (or none). I fixed trace-cmd to get the mappings when qemu is not found, and KernelShark works fine on that case. This bug only appears when it can't find the host thread that corresponds to the guest vCPU. -- Steve
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