diff options
Diffstat (limited to 'gitlab/issues_text/target_ppc/host_missing/accel_missing/1509')
| -rw-r--r-- | gitlab/issues_text/target_ppc/host_missing/accel_missing/1509 | 161 |
1 files changed, 0 insertions, 161 deletions
diff --git a/gitlab/issues_text/target_ppc/host_missing/accel_missing/1509 b/gitlab/issues_text/target_ppc/host_missing/accel_missing/1509 deleted file mode 100644 index 14f7b5822..000000000 --- a/gitlab/issues_text/target_ppc/host_missing/accel_missing/1509 +++ /dev/null @@ -1,161 +0,0 @@ -ppc64 tcg guests get incorrect Capacity Entitlement values from SMP spapr machine's RTAS - examples given from AIX guest OS -Description of problem: -Entitled Capacity of the guest OS is not equal to the number of vCPUs you configure with QEMU. - -It only gives you 1/4 entitlements to your configured capacity, and if you increase the number of processors, it converts the LPAR capacity to hundredths of a core, throttling guest performance. -Steps to reproduce: -Definition of terms from lparstat: -Entitled Capacity: The number of processing units this LPAR is entitled to receive. -Maximum Capacity: The maximum number of processing units this LPAR was defined to ever have. Entitled capacity can be increased up to this value. - -Some examples: - -1 QEMU vCPU: -Entitled Capacity: 0.25 -Maximum Capacity: 1.00 - -2 QEMU vCPUs (-smp cpus=2,sockets=1,cores=2,threads=1): -Entitled Capacity = 0.50 -Maximum Capacity: 0.02 - -3 QEMU CPUs (-smp cpus=3,sockets=1,cores=3,threads=1): -Entitled Capacity = 0.75 -Maximum Capacity: 0.03 - -4 QEMU CPUs (-smp cpus=4,sockets=1,cores=4,threads=1): -Entitled Capacity = 1.00 -Maximum Capacity: 0.04 - -I believe these Entitled and Maximum values are comming from the spapr machine's MaxEntCap, DesProcs and MaxPlatProcs settings which get affected by -smp passed to QEMU. -Additional information: -Details: - -1 QEMU vCPU: - ``` -kens@aix-ppc64$ lparstat -i | head -20 -Node Name : aix-ppc64 -Partition Name : IBM AIX - IBM POWER9 -Partition Number : 0 -Type : Shared -Mode : Capped -Entitled Capacity : 0.25 -Partition Group-ID : 1 -Shared Pool ID : 1 -Online Virtual CPUs : 1 -Maximum Virtual CPUs : 1 -Minimum Virtual CPUs : 1 -Online Memory : 8192 MB -Maximum Memory : 8192 MB -Minimum Memory : 8192 MB -Variable Capacity Weight : 128 -Minimum Capacity : 0.01 -Maximum Capacity : 1.00 -Capacity Increment : 1.00 -Maximum Physical CPUs in system : 1 -Active Physical CPUs in system : 1 - ``` -2 QEMU vCPUs: - ``` -kens@aix-ppc64$ lparstat -i | head -20 -Node Name : aix-ppc64 -Partition Name : IBM AIX - IBM POWER9 -Partition Number : 0 -Type : Shared -Mode : Capped -Entitled Capacity : 0.50 -Partition Group-ID : 1 -Shared Pool ID : 1 -Online Virtual CPUs : 2 -Maximum Virtual CPUs : 2 -Minimum Virtual CPUs : 2 -Online Memory : 8192 MB -Maximum Memory : 8192 MB -Minimum Memory : 8192 MB -Variable Capacity Weight : 128 -Minimum Capacity : 0.02 -Maximum Capacity : 0.02 -Capacity Increment : 1.00 -Maximum Physical CPUs in system : 2 -Active Physical CPUs in system : 2 - ``` -3 QEMU vCPUs: - ``` -kens@aix-ppc64$ lparstat -i | head -20 -Node Name : aix-ppc64 -Partition Name : IBM AIX - IBM POWER9 -Partition Number : 0 -Type : Shared -Mode : Capped -Entitled Capacity : 0.75 -Partition Group-ID : 1 -Shared Pool ID : 1 -Online Virtual CPUs : 3 -Maximum Virtual CPUs : 3 -Minimum Virtual CPUs : 3 -Online Memory : 8192 MB -Maximum Memory : 8192 MB -Minimum Memory : 8192 MB -Variable Capacity Weight : 128 -Minimum Capacity : 0.03 -Maximum Capacity : 0.03 -Capacity Increment : 1.00 -Maximum Physical CPUs in system : 3 -Active Physical CPUs in system : 3 - ``` -4 QEMU vCPUs: - ``` -kens@aix-ppc64$ lparstat -i | head -2 -lparstat -i | head -2 -Node Name : aix-ppc64 -Partition Name : IBM AIX - IBM POWER9 -kens@aix-ppc64$ lparstat -i | head -20 -lparstat -i | head -20 -Node Name : aix-ppc64 -Partition Name : IBM AIX - IBM POWER9 -Partition Number : 0 -Type : Shared -Mode : Capped -Entitled Capacity : 1.00 -Partition Group-ID : 1 -Shared Pool ID : 1 -Online Virtual CPUs : 4 -Maximum Virtual CPUs : 4 -Minimum Virtual CPUs : 4 -Online Memory : 8192 MB -Maximum Memory : 8192 MB -Minimum Memory : 8192 MB -Variable Capacity Weight : 128 -Minimum Capacity : 0.04 -Maximum Capacity : 0.04 -Capacity Increment : 1.00 -Maximum Physical CPUs in system : 4 -Active Physical CPUs in system : 4 - ``` -So it seems to me like the OS assumes the following from the spapr machine settings: -Entitled Capacity = cpus / 4 (OS is assuming smt=4 threads maybe, see below) -Maximim Capacity = cpus / 100 (OS is assuming hundredths of a core, even though the Capacity Increment is 1.00, see below)) - -On a real Power system (POWER8, smt=8), it looks like this: - ``` -kens@aix72$ lparstat -i | head -20 -Node Name : aix72 -Partition Name : n1 -Partition Number : 1 -Type : Shared-SMT-4 -Mode : Uncapped -Entitled Capacity : 6.00 -Partition Group-ID : 32784 -Shared Pool ID : 0 -Online Virtual CPUs : 12 -Maximum Virtual CPUs : 28 -Minimum Virtual CPUs : 1 -Online Memory : 131072 MB -Maximum Memory : 196608 MB -Minimum Memory : 1024 MB -Variable Capacity Weight : 128 -Minimum Capacity : 0.50 -Maximum Capacity : 14.00 -Capacity Increment : 0.01 -Maximum Physical CPUs in system : 80 -Active Physical CPUs in system : 80 - ``` |