Modify qemuProcessStart() in order to allowing setting affinity to
specific CPU's for IOThreads. The process followed is similar to
that for the vCPU's.
This involves adding a function to fetch the IOThread id's via
qemuMonitorGetIOThreads() and adding them to iothreadpids[] list.
Then making sure all the cgroup data has been properly set up and
finally assigning affinity.
Signed-off-by: John Ferlan <jferlan@xxxxxxxxxx>
---
src/qemu/qemu_driver.c | 8 +++++
src/qemu/qemu_process.c | 96 +++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 104 insertions(+)
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 239a300..cb94b02 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -8733,6 +8733,14 @@ qemuDomainSetNumaParamsLive(virDomainObjPtr vm,
virCgroupSetCpusetMems(priv->cgroup, nodeset_str) < 0)
goto cleanup;
+ for (i = 0; i < priv->niothreadpids; i++) {
+ if (virCgroupNewIOThread(priv->cgroup, i, false, &cgroup_temp) < 0 ||
+ virCgroupSetCpusetMems(cgroup_temp, nodeset_str) < 0)
+ goto cleanup;
+ virCgroupFree(&cgroup_temp);
+ }
+
+
ret = 0;
cleanup:
VIR_FREE(nodeset_str);
diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index f76aa5a..3a02b9e 100644
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -2089,6 +2089,49 @@ qemuProcessDetectVcpuPIDs(virQEMUDriverPtr driver,
}
+static int
+qemuProcessDetectIOThreadPIDs(virQEMUDriverPtr driver,
+ virDomainObjPtr vm,
+ int asyncJob)
+{
+ qemuDomainObjPrivatePtr priv = vm->privateData;
+ qemuMonitorIOThreadsInfoPtr *iothreads = NULL;
+ int niothreads = 0;
+ int ret = -1;
+ size_t i;
+
+ /* Get the list of IOThreads from qemu */
+ if (qemuDomainObjEnterMonitorAsync(driver, vm, asyncJob) < 0)
+ goto cleanup;
+ niothreads = qemuMonitorGetIOThreads(priv->mon, &iothreads);
+ qemuDomainObjExitMonitor(driver, vm);
+ if (niothreads <= 0)
+ goto cleanup;
+
+ if (niothreads != vm->def->iothreads) {
+ virReportError(VIR_ERR_INTERNAL_ERROR,
+ _("got wrong number of IOThread pids from QEMU monitor. "
+ "got %d, wanted %d"),
+ niothreads, vm->def->iothreads);
+ goto cleanup;
+ }
+
+ if (VIR_ALLOC_N(priv->iothreadpids, niothreads) < 0)
+ goto cleanup;
+ priv->niothreadpids = niothreads;
+
+ for (i = 0; i < priv->niothreadpids; i++)
+ priv->iothreadpids[i] = iothreads[i]->thread_id;
+
+ ret = 0;
+
+ cleanup:
+ for (i = 0; i < niothreads; i++)
+ qemuMonitorIOThreadsInfoFree(iothreads[i]);
+ VIR_FREE(iothreads);
+ return ret;
+}
+
/* Helper to prepare cpumap for affinity setting, convert
* NUMA nodeset into cpuset if @nodemask is not NULL, otherwise
* just return a new allocated bitmap.
@@ -2281,6 +2324,41 @@ qemuProcessSetEmulatorAffinity(virDomainObjPtr vm)
return ret;
}
+/* Set CPU affinities for IOThreads threads. */
+static int
+qemuProcessSetIOThreadsAffinity(virDomainObjPtr vm)
+{
+ qemuDomainObjPrivatePtr priv = vm->privateData;
+ virDomainDefPtr def = vm->def;
+ virDomainVcpuPinDefPtr pininfo;
+ size_t i;
+ int ret = -1;
+
+ if (!def->cputune.niothreadspin)
+ return 0;
+
+ if (priv->iothreadpids == NULL) {
+ virReportError(VIR_ERR_OPERATION_INVALID,
+ "%s", _("IOThread affinity is not supported"));
+ return -1;
+ }
+
+ for (i = 0; i < def->iothreads; i++) {
+ /* set affinity only for existing vcpus */
+ if (!(pininfo = virDomainVcpuPinFindByVcpu(def->cputune.iothreadspin,
+ def->cputune.niothreadspin,
+ i+1)))
+ continue;
+
+ if (virProcessSetAffinity(priv->iothreadpids[i], pininfo->cpumask) < 0)
+ goto cleanup;
+ }
+ ret = 0;
+
+ cleanup:
+ return ret;
+}
+
static int
qemuProcessInitPasswords(virConnectPtr conn,
virQEMUDriverPtr driver,
@@ -4268,6 +4346,10 @@ int qemuProcessStart(virConnectPtr conn,
if (qemuProcessDetectVcpuPIDs(driver, vm, asyncJob) < 0)
goto cleanup;
+ VIR_DEBUG("Detecting IOThread PIDs");
+ if (qemuProcessDetectIOThreadPIDs(driver, vm, asyncJob) < 0)
+ goto cleanup;
+
VIR_DEBUG("Setting cgroup for each VCPU (if required)");
if (qemuSetupCgroupForVcpu(vm) < 0)
goto cleanup;
@@ -4276,6 +4358,10 @@ int qemuProcessStart(virConnectPtr conn,
if (qemuSetupCgroupForEmulator(driver, vm, nodemask) < 0)
goto cleanup;
+ VIR_DEBUG("Setting cgroup for each IOThread (if required)");
+ if (qemuSetupCgroupForIOThreads(vm) < 0)
+ goto cleanup;
+
VIR_DEBUG("Setting VCPU affinities");
if (qemuProcessSetVcpuAffinities(vm) < 0)
goto cleanup;
@@ -4284,6 +4370,10 @@ int qemuProcessStart(virConnectPtr conn,
if (qemuProcessSetEmulatorAffinity(vm) < 0)
goto cleanup;
+ VIR_DEBUG("Setting affinity of IOThread threads");
+ if (qemuProcessSetIOThreadsAffinity(vm) < 0)
+ goto cleanup;
+
VIR_DEBUG("Setting any required VM passwords");
if (qemuProcessInitPasswords(conn, driver, vm, asyncJob) < 0)
goto cleanup;
@@ -4697,6 +4787,8 @@ void qemuProcessStop(virQEMUDriverPtr driver,
virDomainObjSetState(vm, VIR_DOMAIN_SHUTOFF, reason);
VIR_FREE(priv->vcpupids);
priv->nvcpupids = 0;
+ VIR_FREE(priv->iothreadpids);
+ priv->niothreadpids = 0;
virObjectUnref(priv->qemuCaps);
priv->qemuCaps = NULL;
VIR_FREE(priv->pidfile);
@@ -4889,6 +4981,10 @@ int qemuProcessAttach(virConnectPtr conn ATTRIBUTE_UNUSED,
if (qemuProcessDetectVcpuPIDs(driver, vm, QEMU_ASYNC_JOB_NONE) < 0)
goto error;
+ VIR_DEBUG("Detecting IOThread PIDs");
+ if (qemuProcessDetectIOThreadPIDs(driver, vm, QEMU_ASYNC_JOB_NONE) < 0)
+ goto error;
+
/* If we have -device, then addresses are assigned explicitly.
* If not, then we have to detect dynamic ones here */
if (!virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_DEVICE)) {
--
1.9.3
--
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