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Description of problem: The CPU utilization of RHEL6.8 is twice as high as that of RHEL5.11 and RHEL7.2 during communication Version-Release number of selected component (if applicable): netperf:ftp://ftp.netperf.org/netperf/netperf-2.7.0.tar.gz host kernel:2.6.32-598.el6.x86_64 qemu-kvm:qemu-kvm-0.12.1.2-2.483.el6.x86_64 7.2z guest kernel:3.10.0-327.el7.x86_64 6.8 guest kernel:2.6.32-598.el6.x86_64 5.11 guest kernel:2.6.18-398.el5 How reproducible: Steps to Reproduce: 1.Boot rhel6.8 guest with 17 virtio blk devices and 3 virtio net devices: /usr/libexec/qemu-kvm -name rhel6.7 -m 4G \ -smp 4 \ -cpu SandyBridge,check \ -vga qxl\ -spice port=3002,disable-ticketing \ -device virtio-serial -chardev spicevmc,id=vdagent,debug=0,name=vdagent \ -serial unix:/tmp/m,server,nowait \ -device virtserialport,chardev=vdagent,name=com.redhat.spice.0 \ -drive file=gluster://10.66.10.61/mygluster/30Ggluster511.qcow2,if=none,id=drive-virtio-disk0,format=qcow2,cache=none,werror=stop,rerror=stop,aio=threads,serial=aguoaguoaguo\ -device virtio-blk-pci,bus=pci.0,drive=drive-virtio-disk0,vectors=0,scsi=off,id=drive-virtio-disk0\ -monitor stdio \ -netdev tap,id=idinWyYp,vhost=on -device virtio-net-pci,mac=42:ce:a9:d2:4d:d7,id=idlbq7eA,netdev=idinWyYp \ -usb -device usb-kbd,id=input0 \ -netdev tap,id=idinWyYp1 -device virtio-net-pci,mac=43:ce:a9:d2:4d:d7,id=idlbq7eb,netdev=idinWyYp1 \ -netdev tap,id=idinWyYp2 -device virtio-net-pci,mac=44:ce:a9:d2:4d:d7,id=idlbq7ec,netdev=idinWyYp2 \ -drive file=gluster://10.66.10.61/mygluster/data1.qcow2,if=none,id=drive-virtio-disk1,format=qcow2,cache=none,werror=stop,rerror=stop,aio=threads\ -device virtio-blk-pci,drive=drive-virtio-disk1,scsi=off,id=drive-virtio-disk1\ -drive file=gluster://10.66.10.61/mygluster/data2.qcow2,if=none,id=drive-virtio-disk2,format=qcow2,cache=none,werror=stop,rerror=stop,aio=threads\ -device virtio-blk-pci,drive=drive-virtio-disk2,scsi=off,id=drive-virtio-disk2\ -drive file=gluster://10.66.10.61/mygluster/data3.qcow2,if=none,id=drive-virtio-disk3,format=qcow2,cache=none,werror=stop,rerror=stop,aio=threads\ -device virtio-blk-pci,drive=drive-virtio-disk3,scsi=off,id=drive-virtio-disk3\ -drive file=gluster://10.66.10.61/mygluster/data4.qcow2,if=none,id=drive-virtio-disk4,format=qcow2,cache=none,werror=stop,rerror=stop,aio=threads\ -device virtio-blk-pci,drive=drive-virtio-disk4,scsi=off,id=drive-virtio-disk4\ -drive file=gluster://10.66.10.61/mygluster/data5.qcow2,if=none,id=drive-virtio-disk5,format=qcow2,cache=none,werror=stop,rerror=stop,aio=threads\ -device virtio-blk-pci,drive=drive-virtio-disk5,scsi=off,id=drive-virtio-disk5\ -drive file=gluster://10.66.10.61/mygluster/data6.qcow2,if=none,id=drive-virtio-disk6,format=qcow2,cache=none,werror=stop,rerror=stop,aio=threads\ -device virtio-blk-pci,drive=drive-virtio-disk6,scsi=off,id=drive-virtio-disk6\ -drive file=gluster://10.66.10.61/mygluster/data7.qcow2,if=none,id=drive-virtio-disk7,format=qcow2,cache=none,werror=stop,rerror=stop,aio=threads\ -device virtio-blk-pci,drive=drive-virtio-disk7,scsi=off,id=drive-virtio-disk7\ -drive file=gluster://10.66.10.61/mygluster/data8.qcow2,if=none,id=drive-virtio-disk8,format=qcow2,cache=none,werror=stop,rerror=stop,aio=threads\ -device virtio-blk-pci,drive=drive-virtio-disk8,scsi=off,id=drive-virtio-disk8\ -drive file=gluster://10.66.10.61/mygluster/data9.qcow2,if=none,id=drive-virtio-disk9,format=qcow2,cache=none,werror=stop,rerror=stop,aio=threads\ -device virtio-blk-pci,drive=drive-virtio-disk9,scsi=off,id=drive-virtio-disk9\ -drive file=gluster://10.66.10.61/mygluster/data10.qcow2,if=none,id=drive-virtio-disk10,format=qcow2,cache=none,werror=stop,rerror=stop,aio=threads\ -device virtio-blk-pci,drive=drive-virtio-disk10,scsi=off,id=drive-virtio-disk10\ -drive file=gluster://10.66.10.61/mygluster/data11.qcow2,if=none,id=drive-virtio-disk11,format=qcow2,cache=none,werror=stop,rerror=stop,aio=threads\ -device virtio-blk-pci,drive=drive-virtio-disk11,scsi=off,id=drive-virtio-disk11\ -drive file=gluster://10.66.10.61/mygluster/data12.qcow2,if=none,id=drive-virtio-disk12,format=qcow2,cache=none,werror=stop,rerror=stop,aio=threads\ -device virtio-blk-pci,drive=drive-virtio-disk12,scsi=off,id=drive-virtio-disk12\ -drive file=gluster://10.66.10.61/mygluster/data13.qcow2,if=none,id=drive-virtio-disk13,format=qcow2,cache=none,werror=stop,rerror=stop,aio=threads\ -device virtio-blk-pci,drive=drive-virtio-disk13,scsi=off,id=drive-virtio-disk13\ -drive file=gluster://10.66.10.61/mygluster/data14.qcow2,if=none,id=drive-virtio-disk14,format=qcow2,cache=none,werror=stop,rerror=stop,aio=threads\ -device virtio-blk-pci,drive=drive-virtio-disk14,scsi=off,id=drive-virtio-disk14\ -drive file=gluster://10.66.10.61/mygluster/data15.qcow2,if=none,id=drive-virtio-disk15,format=qcow2,cache=none,werror=stop,rerror=stop,aio=threads\ -device virtio-blk-pci,drive=drive-virtio-disk15,scsi=off,id=drive-virtio-disk15\ -drive file=gluster://10.66.10.61/mygluster/data16.qcow2,if=none,id=drive-virtio-disk16,format=qcow2,cache=none,werror=stop,rerror=stop,aio=threads\ -device virtio-blk-pci,drive=drive-virtio-disk16,scsi=off,id=drive-virtio-disk16\ -drive file=gluster://10.66.10.61/mygluster/data17.qcow2,if=none,id=drive-virtio-disk17,format=qcow2,cache=none,werror=stop,rerror=stop,aio=threads\ -device virtio-blk-pci,drive=drive-virtio-disk17,scsi=off,id=drive-virtio-disk17\ 2.use taskset to bound vhost to cpu2 # taskset -cp 2 <vhost process ID> 3.use taskset to bound vhost to cpu3 # taskset -cp 3 <qemu process ID> 4.start netsever in guest and netperf client in another host. 5.start sar(in host): sar -P 2,3 -u 1 100 6.redo step1 ~ step5 with latest RHEL5-11 and latest RHEL 7.2z 7.compare the cpu utilization Actual results: The CPU utilization of RHEL6.8 is almost twice as high as that of RHEL5.11 and RHEL7.2 during netperf communication Expected results: The CPU utilization of RHEL6.8 should same as that of RHEL5.11 and RHEL7.2 during netperf communication Additional info: netperf statistic: Rhel 7.2z guest Average: CPU %user %nice %system %iowait %steal %idle Average: 2 0.00 0.00 8.16 0.00 0.00 91.84 Average: 3 0.13 0.00 0.47 0.00 0.00 99.40 Rhel 6.8 guest Average: CPU %user %nice %system %iowait %steal %idle Average: 2 2.71 0.00 1.41 0.00 0.00 95.88 Average: 3 7.60 0.00 20.81 0.00 0.00 71.59 Rhel 5.11 guest Average: CPU %user %nice %system %iowait %steal %idle Average: 2 0.64 0.00 8.23 0.00 0.00 91.13 Average: 3 0.32 0.00 0.90 0.00 0.00 98.77
Can you measure the cpu utilization on host?
Test on host with kernel:2.6.32-598.el6.x86_64: Average: CPU %user %nice %system %iowait %steal %idle Average: all 0.03 0.00 0.79 0.04 0.00 99.14 Average: 0 0.20 0.00 10.40 0.00 0.00 89.41 Average: 1 0.00 0.00 0.04 0.01 0.00 99.95 Average: 2 0.00 0.00 0.00 0.00 0.00 100.00 Average: 3 0.00 0.00 0.00 0.00 0.00 100.00 Average: 4 0.00 0.00 0.00 0.00 0.00 100.00 Average: 5 0.00 0.00 0.00 0.00 0.00 100.00 Average: 6 0.03 0.00 0.02 0.00 0.00 99.95 Average: 7 0.00 0.00 0.01 0.50 0.00 99.49 Average: 8 0.01 0.00 0.01 0.00 0.00 99.98 Average: 9 0.07 0.00 0.28 0.00 0.00 99.65 Average: 10 0.01 0.00 0.02 0.00 0.00 99.97 Average: 11 0.00 0.00 0.00 0.00 0.00 100.00 cpu utilization very like result on 7.2z guest and 5.11 guest
(In reply to Guo, Zhiyi from comment #3) > Test on host with kernel:2.6.32-598.el6.x86_64: > Average: CPU %user %nice %system %iowait %steal > %idle > Average: all 0.03 0.00 0.79 0.04 0.00 > 99.14 > Average: 0 0.20 0.00 10.40 0.00 0.00 > 89.41 > Average: 1 0.00 0.00 0.04 0.01 0.00 > 99.95 > Average: 2 0.00 0.00 0.00 0.00 0.00 > 100.00 > Average: 3 0.00 0.00 0.00 0.00 0.00 > 100.00 > Average: 4 0.00 0.00 0.00 0.00 0.00 > 100.00 > Average: 5 0.00 0.00 0.00 0.00 0.00 > 100.00 > Average: 6 0.03 0.00 0.02 0.00 0.00 > 99.95 > Average: 7 0.00 0.00 0.01 0.50 0.00 > 99.49 > Average: 8 0.01 0.00 0.01 0.00 0.00 > 99.98 > Average: 9 0.07 0.00 0.28 0.00 0.00 > 99.65 > Average: 10 0.01 0.00 0.02 0.00 0.00 > 99.97 > Average: 11 0.00 0.00 0.00 0.00 0.00 > 100.00 > > cpu utilization very like result on 7.2z guest and 5.11 guest So it does not looks like an issue for me. For several reasons, measuring the cpu utilization in guest is not accurate. So close this as NOTABUG. Thanks