On Mon, Jul 15, 2013 at 09:41:19PM +0200, Christian Borntraeger wrote: > When running with trace backend e.g. "simple" the writer thread needs to be > implemented in the same process context as the trace points that will be > processed. Under libvirtd control, qemu gets first started in daemonized > mode to privide its capabilities. Creating the writer thread in the initial > process context then leads to a dead lock because the thread gets termined > together with the initial parent. (-daemonize) This results in > stale qemu processes. > Fix this by deferring trace initialization.
I don't think this works since trace events will fill up trace_buf[] and eventually invoke flush_trace_file(). At that point we use trace_available_cond and trace_empty_cond, which may be NULL in Glib <2.31.0. Perhaps this can be made safe by checking trace_writeout_enabled. It will be false before the backend has been initialized. Stefan
