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fix: enforce the minimum cgroup cpu shares value to 2 #10221

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Merged
Pearl1594 merged 1 commit into from
Feb 25, 2025
Merged

fix: enforce the minimum cgroup cpu shares value to 2 #10221

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32 changes: 25 additions & 7 deletions ...rvisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/LibvirtComputingResource.java
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Original file line number Diff line number Diff line change
Expand Up @@ -321,6 +321,16 @@ public class LibvirtComputingResource extends ServerResourceBase implements Serv
public static final String UBUNTU_WINDOWS_GUEST_CONVERSION_SUPPORTED_CHECK_CMD = "dpkg -l virtio-win";
public static final String UBUNTU_NBDKIT_PKG_CHECK_CMD = "dpkg -l nbdkit";

public static final int LIBVIRT_CGROUP_CPU_SHARES_MIN = 2;
public static final int LIBVIRT_CGROUP_CPU_SHARES_MAX = 262144;
/**
* The minimal value for the LIBVIRT_CGROUPV2_WEIGHT_MIN is actually 1.
* However, due to an old libvirt bug, it is raised to 2.
* See: https://github.com/libvirt/libvirt/commit/38af6497610075e5fe386734b87186731d4c17ac
*/
public static final int LIBVIRT_CGROUPV2_WEIGHT_MIN = 2;
public static final int LIBVIRT_CGROUPV2_WEIGHT_MAX = 10000;

private String modifyVlanPath;
private String versionStringPath;
private String patchScriptPath;
Expand Down Expand Up @@ -502,8 +512,6 @@ public class LibvirtComputingResource extends ServerResourceBase implements Serv

private static int hostCpuMaxCapacity = 0;

private static final int CGROUP_V2_UPPER_LIMIT = 10000;

private static final String COMMAND_GET_CGROUP_HOST_VERSION = "stat -fc %T /sys/fs/cgroup/";

public static final String CGROUP_V2 = "cgroup2fs";
Expand Down Expand Up @@ -2794,14 +2802,24 @@ public int calculateCpuShares(VirtualMachineTO vmTO) {
int requestedCpuShares = vCpus * cpuSpeed;
int hostCpuMaxCapacity = getHostCpuMaxCapacity();

// cgroup v2 is in use
if (hostCpuMaxCapacity > 0) {
int updatedCpuShares = (int) Math.ceil((requestedCpuShares * CGROUP_V2_UPPER_LIMIT) / (double) hostCpuMaxCapacity);
LOGGER.debug(String.format("This host utilizes cgroupv2 (as the max shares value is [%s]), thus, the VM requested shares of [%s] will be converted to " +
"consider the host limits; the new CPU shares value is [%s].", hostCpuMaxCapacity, requestedCpuShares, updatedCpuShares));

int updatedCpuShares = (int) Math.ceil((requestedCpuShares * LIBVIRT_CGROUPV2_WEIGHT_MAX) / (double) hostCpuMaxCapacity);
LOGGER.debug("This host utilizes cgroupv2 (as the max shares value is [{}]), thus, the VM requested shares of [{}] will be converted to " +
"consider the host limits; the new CPU shares value is [{}].", hostCpuMaxCapacity, requestedCpuShares, updatedCpuShares);

if (updatedCpuShares < LIBVIRT_CGROUPV2_WEIGHT_MIN) updatedCpuShares = LIBVIRT_CGROUPV2_WEIGHT_MIN;
if (updatedCpuShares > LIBVIRT_CGROUPV2_WEIGHT_MAX) updatedCpuShares = LIBVIRT_CGROUPV2_WEIGHT_MAX;
return updatedCpuShares;
}
LOGGER.debug(String.format("This host does not have a maximum CPU shares set; therefore, this host utilizes cgroupv1 and the VM requested CPU shares [%s] will not be " +
"converted.", requestedCpuShares));

// cgroup v1 is in use
LOGGER.debug("This host does not have a maximum CPU shares set; therefore, this host utilizes cgroupv1 and the VM requested CPU shares [{}] will not be " +
"converted.", requestedCpuShares);

if (requestedCpuShares < LIBVIRT_CGROUP_CPU_SHARES_MIN) requestedCpuShares = LIBVIRT_CGROUP_CPU_SHARES_MIN;
if (requestedCpuShares > LIBVIRT_CGROUP_CPU_SHARES_MAX) requestedCpuShares = LIBVIRT_CGROUP_CPU_SHARES_MAX;
return requestedCpuShares;
}

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