On Thu, Jan 14, 2021 at 12:13 AM Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
>
>
> I'm assuming that you can pair multiple guests with a single host?
Yes, this use case is tested using KernelShark. I'll extend the
example in the man page.
>
> That is, can we have:
>
>
> bool g1 = false, g2 = false;
>
> host = tracecmd_open_head("trace.dat");
> tracecmd_init_data(host);
> guest1 = tracecmd_open_head("trace-Guest-1.dat");
> guest2 = tracecmd_open_head("trace-Guest-2.dat");
>
> guest_id_1 = tracecmd_get_traceid(guest1);
> guest_id_2 = tracecmd_get_traceid(guest1);
>
> if (!tracecmd_get_guest_cpumap(host, guest_id_1, &name1, &vcount1, &cpu_pids1)
> g1 = !tracecmd_init_data(guest1);
>
> if (!tracecmd_get_guest_cpumap(host, guest_id_2, &name2, &vcount2, &cpu_pids2)
> g2 = !tracecmd_init_data(guest2);
>
> if (g1) {
> int i;
> for (i = 0; i < vcount1; i++) {
> printf("Host task id %d maps to guest %s cpu %d\n",
> cpu_pids1[i], name1, i);
> }
> tracecmd_unpair_peer(guest1);
> }
>
> if (g2) {
> int i;
> for (i = 0; i < vcount2; i++) {
> printf("Host task id %d maps to guest %s cpu %d\n",
> cpu_pids2[i], name2, i);
> }
> tracecmd_unpair_peer(guest2);
> }
>
> And use something like the above for the example?
>
> -- Steve
>
>
> On Wed, 23 Dec 2020 06:34:28 +0200
> "Tzvetomir Stoyanov (VMware)" <tz.stoyanov@xxxxxxxxx> wrote:
>
> > +EXAMPLE
> > +-------
> > +[source,c]
> > +--
> > +#include <trace-cmd.h>
> > +...
> > +struct tracecmd_input *host = tracecmd_open_head("trace.dat");
> > + if (!host) {
> > + /* Failed to open host trace file */
> > + }
> > + tracecmd_init_data(host);
> > +
> > +struct tracecmd_input *guest = tracecmd_open_head("trace-Guest.dat");
> > + if (!guest) {
> > + /* Failed to open guest trace file */
> > + }
> > +
> > +unsigned long long guest_id = tracecmd_get_traceid(guest);
> > +int *cpu_pid;
> > +char *name;
> > +int vcount;
> > +
> > + if (!tracecmd_get_guest_cpumap(host, guest_id, &name, &vcount, &cpu_pid)) {
> > + /* The Host and a guest with name was part of the same trace session.
> > + * Got guest VCPU to host PID mapping.
> > + */
> > + if (!tracecmd_pair_peer(guest, host)) {
> > + /* Successfully paired host to the guest handler */
> > + tracecmd_init_data(guest);
> > + ...
> > + tracecmd_unpair_peer(guest);
> > + }
> > + }
> > +
> > +...
> > + tracecmd_close(guest);
> > + tracecmd_close(hadle);
> > +
> > +--
--
Tzvetomir (Ceco) Stoyanov
VMware Open Source Technology Center
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