File libvirt-qemu-cgroup-Properly-set-up-vcpu-pinning.patch of Package libvirt
From e939127cc75e04a31460fb59cf34872d197f74c2 Mon Sep 17 00:00:00 2001
Message-Id: <e939127cc75e04a31460fb59cf34872d197f74c2@dist-git>
From: Peter Krempa <pkrempa@redhat.com>
Date: Thu, 2 Apr 2015 10:31:11 +0200
Subject: [PATCH] qemu: cgroup: Properly set up vcpu pinning
https://bugzilla.redhat.com/show_bug.cgi?id=1198096 [6.7]
https://bugzilla.redhat.com/show_bug.cgi?id=1209891 [6.6.z]
When the default cpuset or automatic numa placement is used libvirt
would place the whole parent cgroup in the specified cpuset. This then
disallowed to re-pin the vcpus to a different cpu.
This patch pins only the vcpu threads to the default cpuset and thus
allows to re-pin them later.
The following config would fail to start:
<domain type='kvm'>
...
<vcpu placement='static' cpuset='0-1' current='2'>4</vcpu>
<cputune>
<vcpupin vcpu='0' cpuset='2-3'/>
...
This is a regression since 298eb3db0a033777bd5091ff21bea72d5e1839cc that
fixed bug https://bugzilla.redhat.com/show_bug.cgi?id=1012846.
This is a reimplementation based on upstream commit
f0fa9080d47b7aedad6f4884b8879d88688752 , but written from scratch
since the code diverged too much.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
---
src/qemu/qemu_cgroup.c | 76 ++++++++++++++++++++-----------------------------
src/qemu/qemu_cgroup.h | 4 ++-
src/qemu/qemu_process.c | 2 +-
3 files changed, 35 insertions(+), 47 deletions(-)
diff --git a/src/qemu/qemu_cgroup.c b/src/qemu/qemu_cgroup.c
index 99be07e..0060bc2 100644
--- a/src/qemu/qemu_cgroup.c
+++ b/src/qemu/qemu_cgroup.c
@@ -432,38 +432,6 @@ int qemuSetupCgroup(struct qemud_driver *driver,
}
}
- if (vm->def->cpumask ||
- (vm->def->placement_mode == VIR_DOMAIN_CPU_PLACEMENT_MODE_AUTO)) {
- char *cpu_mask = NULL;
-
-
- if (vm->def->placement_mode == VIR_DOMAIN_CPU_PLACEMENT_MODE_AUTO) {
- virBitmapPtr cpumap;
-
- cpumap = virCapabilitiesGetCpusForNodemask(driver->caps, nodemask);
- if (!cpumap)
- goto cleanup;
- cpu_mask = virBitmapFormat(cpumap);
- virBitmapFree(cpumap);
- } else {
- cpu_mask = virBitmapFormat(vm->def->cpumask);
- }
-
- if (!cpu_mask) {
- virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
- _("failed to convert cpu mask"));
- goto cleanup;
- }
-
- rc = virCgroupSetCpusetCpus(cgroup, cpu_mask);
- VIR_FREE(cpu_mask);
- if (rc != 0) {
- virReportSystemError(-rc,
- _("Unable to set cpuset.cpus for domain %s"),
- vm->def->name);
- goto cleanup;
- }
- }
done:
virCgroupFree(&cgroup);
@@ -568,7 +536,9 @@ cleanup:
return rc;
}
-int qemuSetupCgroupForVcpu(struct qemud_driver *driver, virDomainObjPtr vm)
+int qemuSetupCgroupForVcpu(struct qemud_driver *driver,
+ virDomainObjPtr vm,
+ virBitmapPtr nodemask)
{
virCgroupPtr cgroup = NULL;
virCgroupPtr cgroup_vcpu = NULL;
@@ -578,6 +548,7 @@ int qemuSetupCgroupForVcpu(struct qemud_driver *driver, virDomainObjPtr vm)
unsigned int i, j;
unsigned long long period = vm->def->cputune.period;
long long quota = vm->def->cputune.quota;
+ virBitmapPtr autoCpuset = NULL;
if ((period || quota) &&
(!driver->cgroup ||
@@ -611,6 +582,10 @@ int qemuSetupCgroupForVcpu(struct qemud_driver *driver, virDomainObjPtr vm)
return 0;
}
+ if (vm->def->placement_mode == VIR_DOMAIN_CPU_PLACEMENT_MODE_AUTO &&
+ !(autoCpuset = virCapabilitiesGetCpusForNodemask(driver->caps, nodemask)))
+ goto cleanup;
+
for (i = 0; i < priv->nvcpupids; i++) {
rc = virCgroupForVcpu(cgroup, i, &cgroup_vcpu, 1);
if (rc < 0) {
@@ -637,25 +612,34 @@ int qemuSetupCgroupForVcpu(struct qemud_driver *driver, virDomainObjPtr vm)
/* Set vcpupin in cgroup if vcpupin xml is provided */
if (qemuCgroupControllerActive(driver, VIR_CGROUP_CONTROLLER_CPUSET)) {
- /* find the right CPU to pin, otherwise
- * qemuSetupCgroupVcpuPin will fail. */
+ virBitmapPtr cpumap = NULL;
+
+ /* try to use the default cpu maps */
+ if (vm->def->placement_mode == VIR_DOMAIN_CPU_PLACEMENT_MODE_AUTO)
+ cpumap = autoCpuset;
+ else
+ cpumap = vm->def->cpumask;
+
+
+ /* lookup a more specific pinning info */
for (j = 0; j < def->cputune.nvcpupin; j++) {
- if (def->cputune.vcpupin[j]->vcpuid != i)
- continue;
-
- if (qemuSetupCgroupVcpuPin(cgroup_vcpu,
- def->cputune.vcpupin,
- def->cputune.nvcpupin,
- i) < 0)
- goto cleanup;
-
- break;
+ if (def->cputune.vcpupin[j]->vcpuid == i) {
+ cpumap = def->cputune.vcpupin[j]->cpumask;
+ break;
+ }
}
+
+ if (!cpumap)
+ continue;
+
+ if (qemuSetupCgroupEmulatorPin(cgroup_vcpu, cpumap) < 0)
+ goto cleanup;
}
virCgroupFree(&cgroup_vcpu);
}
+ virBitmapFree(autoCpuset);
virCgroupFree(&cgroup);
return 0;
@@ -670,6 +654,8 @@ cleanup:
virCgroupFree(&cgroup);
}
+ virBitmapFree(autoCpuset);
+
return -1;
}
diff --git a/src/qemu/qemu_cgroup.h b/src/qemu/qemu_cgroup.h
index 50ee092..ed5d757 100644
--- a/src/qemu/qemu_cgroup.h
+++ b/src/qemu/qemu_cgroup.h
@@ -56,7 +56,9 @@ int qemuSetupCgroupVcpuPin(virCgroupPtr cgroup,
int nvcpupin,
int vcpuid);
int qemuSetupCgroupEmulatorPin(virCgroupPtr cgroup, virBitmapPtr cpumask);
-int qemuSetupCgroupForVcpu(struct qemud_driver *driver, virDomainObjPtr vm);
+int qemuSetupCgroupForVcpu(struct qemud_driver *driver,
+ virDomainObjPtr vm,
+ virBitmapPtr nodemask);
int qemuSetupCgroupForEmulator(struct qemud_driver *driver,
virDomainObjPtr vm,
virBitmapPtr nodemask);
diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index e872497..3e00afb 100644
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -4199,7 +4199,7 @@ int qemuProcessStart(virConnectPtr conn,
goto cleanup;
VIR_DEBUG("Setting cgroup for each VCPU (if required)");
- if (qemuSetupCgroupForVcpu(driver, vm) < 0)
+ if (qemuSetupCgroupForVcpu(driver, vm, nodemask) < 0)
goto cleanup;
VIR_DEBUG("Setting cgroup for emulator (if required)");
--
2.3.5
