-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 Hi, I've recently increased the number of guests (+20%) running on one of my hosts and found that the responsiveness suffered. Before that, the context switches were hovering around 10K, now they're close to 30K. Or this could just be because I upgraded the host kernel and kvm: host and guests are running 2.6.29.4 + kvm-86 Is there anything that can be done to reduce this? I thought dynticks would prevent unecessary context switching? As you can see from the dstat sample below, the host can be very quiet at times, and yet the guests are a bit sluggish. (there is no swapping going on in the guests either) Is 30K context switches normal for a host that's mostly idle?? Here is a sample guest command line: - -clock dynticks -usbdevice tablet -m 1024 -monitor telnet:127.0.0.1:10005,server,nowait -L ./ -kernel ./bzImage-2.6.29.4 - -append earlyprintk=serial,ttyS0,115200,keep console=ttyS0,115200 root=/dev/vda elevator=noop -nographic -drive file=./vm/root_fs,if=virtio,boot=on -net nic,vlan=14,macaddr=fe:f0:00:00:00:0e,model=virtio -net tap,vlan=14,ifname=tap14,script=no Cheers Antoine - ----total-cpu-usage---- -dsk/total- -net/total- ---paging-- ---system-- usr sys idl wai hiq siq| read writ| recv send| in out | int csw 14 15 71 0 0 0| 0 0 | 942B 6912B| 0 0 | 20k 29k 11 17 71 0 0 0| 0 160k| 460B 818B| 0 0 | 19k 30k 9 20 71 0 0 0| 0 0 | 270B 567B| 0 0 | 20k 29k 17 16 66 1 0 0|8192B 1776k| 548B 876B| 0 0 | 20k 31k 8 17 75 0 0 0| 0 336k| 927B 1291B| 0 0 | 20k 29k 13 16 71 0 0 0| 0 1088k|1422B 8505B| 0 296k| 20k 31k 23 14 63 0 0 0| 0 0 |3918B 3058B| 0 0 | 19k 33k 11 16 71 0 0 0|8192B 1120k| 132B 534B| 0 0 | 19k 30k 16 18 66 0 0 0| 0 32k| 330B 7662B| 0 0 | 19k 30k 13 18 69 0 0 0| 0 128k| 264B 420B| 0 0 | 19k 31k 16 17 66 0 0 0| 0 240k| 474B 420B| 0 0 | 19k 30k 11 21 68 0 0 0| 0 1648k| 372B 4196B| 0 0 | 20k 32k 13 18 69 0 0 0| 0 96k| 708B 500B| 0 0 | 20k 30k 15 19 66 0 0 0| 0 256k| 66B 322B| 0 0 | 20k 30k 15 22 63 0 0 0| 0 32k| 804B 8906B| 0 0 | 20k 31k 14 19 67 0 0 0|8192B 256k| 838B 590B|4096B 0 | 19k 31k 13 16 71 0 0 0| 0 0 | 132B 534B| 0 0 | 20k 31k 16 18 62 4 0 0| 312k 976k| 396B 7872B| 156k 0 | 20k 32k 13 22 65 0 0 0| 0 352k| 573B 534B| 0 0 | 19k 31k 14 20 67 0 0 0| 0 160k| 304B 696B| 0 0 | 19k 31k 12 12 74 0 1 0| 0 512k| 514B 4268B| 0 0 | 19k 31k 10 19 72 0 0 0| 0 152k| 290B 420B| 0 0 | 19k 31k 14 18 67 2 0 0| 16k 232k| 224B 306B| 0 0 | 19k 31k 20 23 57 0 0 0| 0 80k|1898B 5544B| 0 0 | 20k 32k 14 14 72 0 0 0| 0 112k|2286B 2482B| 0 0 | 20k 32k 18 17 65 0 0 0| 0 176k|1057B 1169B| 0 0 | 20k 31k 15 13 72 0 0 0| 0 144k| 422B 7614B| 0 0 | 19k 31k 11 15 72 0 0 0| 0 944k| 448B 436B| 0 0 | 19k 31k 9 18 73 0 0 0| 0 1584k| 266B 348B| 0 0 | 19k 33k 15 17 68 0 0 0| 0 0 | 721B 7646B| 0 0 | 20k 31k 14 20 66 0 0 0| 0 0 | 356B 420B| 0 0 | 20k 31k 16 15 69 0 0 0| 0 432k| 532B 420B| 0 0 | 19k 31k 14 18 68 0 0 0| 0 144k| 628B 4058B| 0 0 | 19k 30k 10 20 71 0 0 0| 0 160k| 316B 486B| 0 0 | 20k 31k 11 17 72 0 0 0| 0 80k| 266B 462B| 0 0 | 20k 31k -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEYEAREKAAYFAkobqSwACgkQGK2zHPGK1rumkgCfVkBuS45ouLCCPXV2xSUjeTUd 9FkAnjxl5sufeL+aYUZsuw4sHLEN7UMt =wAwM -----END PGP SIGNATURE----- -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
