Re: [libvirt] [PATCH 3/3] qemu: Report which iothread IDs are actually returned with VIR_DOMAIN_STATS_IOTHREAD

On Fri, Nov 29, 2019 at 09:59:28AM +0100, Peter Krempa wrote: > The design of the stats fields returned for VIR_DOMAIN_STATS_IOTHREAD > domain statistics groups deviates from the established pattern. In this > instance it's impossible to infer which values of <id> for > iothread.<id>... fields will be reported back because they have no > connection to the iothread.count field. Knowing it upfront allows the users to construct the parameter name for the virTypedParamsGet APIs, but processing the returned parameters in this way seems inefficient - I'd expect any serious user to iterate over all the params and collect the iothread <id>s which are reported.

> > Introduce iothread.ids which will report a comma-separated list of <id>s > reported in the subsequent array in the order they will be reported. > Why is the order important? Can it be returned as a stringified bitmap?

> virsh domstats upstream --iothread > Domain: 'upstream' > iothread.count=2 > iothread.ids=7,5 > iothread.7.poll-max-ns=32768 > iothread.7.poll-grow=0 > iothread.7.poll-shrink=0 > iothread.5.poll-max-ns=32768 > iothread.5.poll-grow=0 > iothread.5.poll-shrink=0 > > Signed-off-by: Peter Krempa <pkrempa(a)redhat.com&gt; > --- > src/libvirt-domain.c | 2 ++ > src/qemu/qemu_driver.c | 11 +++++++++++ > 2 files changed, 13 insertions(+) > > diff --git a/src/libvirt-domain.c b/src/libvirt-domain.c > index 87110036ca..e6d5697445 100644 > --- a/src/libvirt-domain.c > +++ b/src/libvirt-domain.c > @@ -11620,6 +11620,8 @@ virConnectGetDomainCapabilities(virConnectPtr conn, > * will use it's iothread_id value as the <id>. There > * may be fewer <id> entries than the iothread.count > * value if the polling values are not supported. > + * "iothread.ids" - a comma separated list of iotdread <id>s reported in the s/iotdread/iothread/ Jano > + * subsequent list reported as a string > * "iothread.<id>.poll-max-ns" - maximum polling time in ns as an unsigned > * long long. A 0 (zero) means polling is > * disabled. > diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c > index b5300241a8..4ccc9d3d4e 100644 > --- a/src/qemu/qemu_driver.c > +++ b/src/qemu/qemu_driver.c > @@ -21189,6 +21189,8 @@ qemuDomainGetStatsIOThread(virQEMUDriverPtr driver, > qemuMonitorIOThreadInfoPtr *iothreads = NULL; > int niothreads; > int ret = -1; > + g_auto(virBuffer) iothridbuf = VIR_BUFFER_INITIALIZER; > + g_autofree char *iothridstr = NULL; > > if (!HAVE_JOB(privflags) || !virDomainObjIsActive(dom)) > return 0; > @@ -21205,6 +21207,15 @@ qemuDomainGetStatsIOThread(virQEMUDriverPtr driver, > if (virTypedParamListAddUInt(params, niothreads, "iothread.count") < 0) > goto cleanup; > > + for (i = 0; i < niothreads; i++) > + virBufferAsprintf(&iothridbuf, "%u,", iothreads[i]->iothread_id); > + > + virBufferTrim(&iothridbuf, ",", -1); > + iothridstr = virBufferContentAndReset(&iothridbuf); > + > + if (virTypedParamListAddString(params, iothridstr, "iothread.ids") < 0) > + goto cleanup; > + > for (i = 0; i < niothreads; i++) { > if (iothreads[i]->poll_valid) { > if (virTypedParamListAddULLong(params, iothreads[i]->poll_max_ns, > -- > 2.23.0 > > -- > libvir-list mailing list > libvir-list(a)redhat.com > https://www.redhat.com/mailman/listinfo/libvir-list