At 07/21/2011 12:34 PM, Daniel Veillard Write:
On Thu, Jul 21, 2011 at 10:11:32AM +0800, Wen Congyang wrote:
--- src/qemu/qemu_driver.c | 312 ++++++++++++++++++++++++++++++++++++++++++++---- 1 files changed, 287 insertions(+), 25 deletions(-)
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index cd65bce..fd80537 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -5139,11 +5139,46 @@ cleanup: }
+/* + * check whether the host supports CFS bandwidth + * + * Return 1 when CFS bandwidth is supported, 0 when CFS bandwidth is not + * supported, -1 on error. + */ +static int qemuGetCpuBWStatus(virCgroupPtr cgroup) +{ + char *cfs_period_path = NULL; + int ret = -1; + + if (!cgroup) + return 0; + + if (virCgroupPathOfController(cgroup, VIR_CGROUP_CONTROLLER_CPU, + "cpu.cfs_period_us", &cfs_period_path) < 0) { + qemuReportError(VIR_ERR_INTERNAL_ERROR, + "%s", + _("cannot get the path of cgroup CPU controller"));
Hum, I'm not sure we should really flag this as an error here It should be made an INFO I think. What should get an error is if we try to start using cpu control on a guest while the host doesn't support it. In practice we need to check proper handling in 3 cases: - at guest startup - on migration when checking the target host - when activated at runtime
Okay, I will change the message level.
+ goto cleanup; + } + + if (access(cfs_period_path, F_OK) < 0) { + ret = 0; + } else { + ret = 1; + } + +cleanup: + VIR_FREE(cfs_period_path); + return ret; +} + + static char *qemuGetSchedulerType(virDomainPtr dom, int *nparams) { struct qemud_driver *driver = dom->conn->privateData; char *ret = NULL; + int rc;
qemuDriverLock(driver); if (!qemuCgroupControllerActive(driver, VIR_CGROUP_CONTROLLER_CPU)) { @@ -5152,8 +5187,15 @@ static char *qemuGetSchedulerType(virDomainPtr dom, goto cleanup; }
- if (nparams) - *nparams = 1; + if (nparams) { + rc = qemuGetCpuBWStatus(driver->cgroup); + if (rc < 0) + goto cleanup; + else if (rc == 0) + *nparams = 1; + else + *nparams = 3; + }
ret = strdup("posix"); if (!ret) @@ -5786,6 +5828,58 @@ cleanup: return ret; }
+static int +qemuSetVcpusBWLive(virDomainObjPtr vm, virCgroupPtr cgroup, + unsigned long long period, long long quota) +{ + int i; + qemuDomainObjPrivatePtr priv = vm->privateData; + virCgroupPtr cgroup_vcpu = NULL; + int rc; + + if (period == 0 && quota == 0) + return 0; + + if (priv->nvcpupids == 0 || priv->vcpupids[0] == vm->pid) { + /* If we does not know VCPU<->PID mapping or all vcpu runs in the same + * thread, we can not control each vcpu. + */ + /* Ensure that we can multiply by vcpus without overflowing. */ + if (quota > LLONG_MAX / vm->def->vcpus) { + virReportSystemError(EINVAL, + _("%s"), + "Unable to set cpu bandwidth quota");
should probably give an hint of why in the error message
EINVAL means the value is invalid. If you think it is not enough, I will change the error message. Thanks Wen Congyang
+ goto cleanup; + } +
snip
ret = 0;
cleanup:
ACK but please add a commit message
Daniel