[libvirt] [PATCH 1/2] qemu: Set emulator thread scheduler only after QEMU starts
If the scheduler is set before vCPU0 cannot be moved into its cpu,cpuacct
cgroup. While it is not yet known whether this is a bug or not, it makes sense
for us to do that later as otherwise the scheduler would be inherited by vCPU
and I/O Threads even when they do not have any such setting specified.
Signed-off-by: Martin Kletzander <mkletzan(a)redhat.com>
---
src/qemu/qemu_process.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index 90466771cd87..fa5909e9bed3 100644
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -2658,8 +2658,9 @@ qemuProcessSetupPid(virDomainObjPtr vm,
if (use_cpumask && virProcessSetAffinity(pid, use_cpumask) < 0)
goto cleanup;
- /* Set scheduler type and priority. */
+ /* Set scheduler type and priority, but not for the main thread. */
if (sched &&
+ nameval != VIR_CGROUP_THREAD_EMULATOR &&
virProcessSetScheduler(pid, sched->policy, sched->priority) < 0)
goto cleanup;
@@ -6773,6 +6774,13 @@ qemuProcessLaunch(virConnectPtr conn,
if (qemuProcessSetupIOThreads(vm) < 0)
goto cleanup;
+ VIR_DEBUG("Setting emulator scheduler");
+ if (vm->def->cputune.emulatorsched &&
+ virProcessSetScheduler(vm->pid,
+ vm->def->cputune.emulatorsched->policy,
+ vm->def->cputune.emulatorsched->priority) <
0)
+ goto cleanup;
+
VIR_DEBUG("Setting any required VM passwords");
if (qemuProcessInitPasswords(driver, vm, asyncJob) < 0)
goto cleanup;
--
2.21.0