Commit 8a745f2a authored Sep 23, 2013 by Michael Mueller Committed by Stefan Hajnoczi Jan 27, 2014

tracing: start trace processing thread in final child process



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)

Signed-off-by: Michael Mueller <mimu@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
[minor whitespace fixes]
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

parent 0169c511

vl.c

+10 −2

Original line number	Diff line number	Diff line
		@@ -3879,9 +3879,11 @@ int main(int argc, char argv, char envp)
		qemu_set_log(mask);
		}

		if (!is_daemonized()) {
		if (!trace_backend_init(trace_events, trace_file)) {
		exit(1);
		}
		}

		/* If no data_dir is specified then try to find it relative to the
		executable path. */
		@@ -4379,6 +4381,12 @@ int main(int argc, char argv, char envp)

		os_setup_post();

		if (is_daemonized()) {
		if (!trace_backend_init(trace_events, trace_file)) {
		exit(1);
		}
		}

		main_loop();
		bdrv_close_all();
		pause_all_vcpus();