Description of problem: start VM with -m 256G ,mouse of guest responds very slowly. Version-Release number of selected component (if applicable): 2.6.18-260.el5 # rpm -q kvm kvm-83-232.el5 guest: RHEL6.1_64 bit How reproducible: 100% Steps to Reproduce: 1.start vm with -m 256G eg:/usr/libexec/qemu-kvm -M rhel5.6.0 -m 256G -smp 16,sockets=16,cores=1,threads=1 -name VM -uuid 502ae056-69fc-4039-b5e8-c9d4918e4a7d -monitor stdio -no-kvm-pit-reinjection -usbdevice tablet -startdate now -boot dc -drive file=/home/test.img,if=virtio,format=qcow2,werror=stop,cache=none,boot=on -net nic,macaddr=54:52:40:20:4c:58,vlan=0,model=virtio -net tap,script=/etc/qemu-ifup,downscript=no,vlan=0 -usb -vnc :3 -k en-us -balloon virtio -notify all -no-hpet -soundhw ac97 Actual results: the mouse of guest responds very slowly Expected results: Additional info: Tried same image with -smp=2 -m=2G ,guest works fine.
host info # free -g total used free shared buffers cached Mem: 504 263 240 0 0 4 -/+ buffers/cache: 258 245 Swap: 33 0 33 #cat /proc/cpuinfo processor : 63 vendor_id : GenuineIntel cpu family : 6 model : 46 model name : Intel(R) Xeon(R) CPU X7550 @ 2.00GHz stepping : 6 cpu MHz : 1995.043 cache size : 18432 KB physical id : 3 siblings : 16 core id : 11 cpu cores : 8 apicid : 119 fpu : yes fpu_exception : yes cpuid level : 11 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm syscall nx rdtscp lm constant_tsc ida nonstop_tsc pni monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr sse4_1 sse4_2 popcnt lahf_lm bogomips : 3990.06 clflush size : 64 cache_alignment : 64 address sizes : 44 bits physical, 48 bits virtual power management: [8]
This host does not seem to have nested page tables. Maybe we're stuck at shadow page handling for too long, and lose interrupts ?
(In reply to comment #2) > This host does not seem to have nested page tables. Maybe we're stuck at shadow > page handling for too long, and lose interrupts ? This host based on intel platform(Nehalem-EX) which support Extended Page Tables (EPT). ---snip form According to http://en.wikipedia.org/wiki/Extended_Page_Table-- Intel states that the feature is available in all their Nehalem-based CPUs with virtualization support. Nested page tables(npt),seems amd named npt or Rapid Virtualization Indexing (RVI) . I also tested on amd platform which support Nested page tables(npt),hit the same issue. Host infos: processor : 46 vendor_id : AuthenticAMD cpu family : 16 model : 9 model name : AMD Opteron(tm) Processor 6172
Is it reproducible with RHEL6.1 ?
(In reply to comment #4) > Is it reproducible with RHEL6.1 ? you mean RHEL6.1 guest or host ? the machine is reserved by others this week , will reply it in next week. Best Regards, mike
(In reply to comment #5) > (In reply to comment #4) > > Is it reproducible with RHEL6.1 ? > > you mean RHEL6.1 guest or host ? the machine is reserved by others this week , > will reply it in next week. > > Best Regards, > mike RHEL6.1 host. Once you have the guest running, please gather profiling information with: # perf record -p $pid_of_qemu_kvm_process move mouse for a few seconds in the guest ctrl + c # perf report --stdio > report.txt And attach report.txt to this BZ. Thanks
Created attachment 502177 [details] report.txt file
(In reply to comment #6) > (In reply to comment #5) > > (In reply to comment #4) > > > Is it reproducible with RHEL6.1 ? > > > > you mean RHEL6.1 guest or host ? the machine is reserved by others this week , > > will reply it in next week. > > > > Best Regards, > > mike > > RHEL6.1 host. Once you have the guest running, please gather profiling > information with: > > # perf record -p $pid_of_qemu_kvm_process > > move mouse for a few seconds in the guest > > ctrl + c > > # perf report --stdio > report.txt > > And attach report.txt to this BZ. > > Thanks this bug can not be reproduced on rhel6.1 host. report.txt file is in attachment steps: 1. start rhel5.7 guest with 400G memory on rhel6.1 host /usr/libexec/qemu-kvm -M rhel6.1.0 -enable-kvm -name rhel5.7 -smp 16 -m 400G -uuid 9e6f04cf-2ad7-45aa-9333-2d2ee26570c6 -boot c -drive file=/mnt/images/rhel57-64.qcow2,if=none,id=drive-ide0-0-0,format=qcow2,boot=on,cache=none -device ide-drive,bus=ide.0,unit=0,drive=drive-ide0-0-0,id=ide0-0-0 -netdev tap,id=hostnet0 -device rtl8139,netdev=hostnet0,id=net0,mac=52:54:00:19:3b:80 -monitor stdio -vga cirrus -vnc :1 2.mount -t debugfs none /sys/kernel/debug 3.echo 1 >/sys/kernel/debug/tracing/events/kvm/enable 4.perf record -p $pid_of_qemu_kvm_process 5.move mouse for a few seconds in the guest 6.perf report --stdio > report.txt
FuXiangChun, Mike, Since it is not reproducible on RHEL6.1, i'm closing the bug as CLOSED CURRENTRELEASE.
fuxiangchun, pls arrange a big machine with latest RHEL5 tree and pre-install windows/linux guest for developer Thanks , Mike
1.reproduce with kvm-83-238.el5 steps to reproduce 1.1. /usr/libexec/qemu-kvm -M rhel5.6.0 -m 500G -smp 16,sockets=16,cores=1,threads=1 -name VM -uuid 502ae056-69fc-4039-b5e8-c9d4918e4a7d -monitor stdio -no-kvm-pit-reinjection -usbdevice tablet -startdate now -boot dc -drive file=/home/qcow2/RHEL-Server-6.2-64.qcow2,if=virtio,format=qcow2,werror=stop,cache=none,boot=on -net nic,macaddr=54:52:40:20:4c:58,vlan=0,model=virtio -net tap,script=/etc/qemu-ifup,downscript=no,vlan=0 -usb -vnc :3 -k en-us -balloon virtio -notify all -no-hpet -soundhw ac97 1.2. test mouse in guest actual result: mouse responds very slowly 2.verify with kvm-83-246.el5 2.1) repeat 1.1 command line 2.2) repeat 1.2 process actual result: mouse work well base on above testing result, this bug is fixed. additional info: cat /proc/cpuinfo model name : AMD Opteron(tm) Processor 6172
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. http://rhn.redhat.com/errata/RHSA-2012-0149.html