traffic with same bandwidth. for example,both 1000 packets per second. 2010/11/23 Huang, Zhiteng <zhiteng.huang@xxxxxxxxx>: > By same traffic load, do you mean same amount of packets or traffic with same bandwidth or anything else? > > Regards, > > HUANG, Zhiteng > > > > -----Original Message----- > From: lidong chen [mailto:chen.lidong.kernel@xxxxxxxxx] > Sent: Tuesday, November 23, 2010 2:53 PM > To: Huang, Zhiteng > Cc: tj@xxxxxxxxxx; sri@xxxxxxxxxx; mst@xxxxxxxxxx; Avi Kivity; kvm@xxxxxxxxxxxxxxx > Subject: Re: Performance test result between per-vhost kthread disable and enable > > I used a special tool, this tool can send and receive packets parallelly. > I set the tool to use the same traffic load. > then i use the tool to test different version of kvm. > > > > 2010/11/23 Huang, Zhiteng <zhiteng.huang@xxxxxxxxx>: >> Hi Lidong, >> >> What do you mean by 'send the same traffic load between...' ? >> >> See if my understanding is correct: >> You have two identical physical machines (CPU/Memory/NIC...), one(A) runs RHEL6 Beta2(2.6.32-60) and the other one (B) runs RHEL6 (2.6.32-71). >> Each machine booted 5 identical VMs and then VMs on machine A (pool A) paired up with VMs on machine B (pool B). Sending packets between two VM pools yielded 20% utilization difference. >> >> Did you test bi-direction traffic, i.e. first pool A sends and pool B receives then vice versa? >> >> Regards, >> >> HUANG, Zhiteng >> >> >> >> -----Original Message----- >> From: kvm-owner@xxxxxxxxxxxxxxx [mailto:kvm-owner@xxxxxxxxxxxxxxx] On >> Behalf Of lidong chen >> Sent: Tuesday, November 23, 2010 10:14 AM >> To: tj@xxxxxxxxxx; sri@xxxxxxxxxx; mst@xxxxxxxxxx; Avi Kivity; >> kvm@xxxxxxxxxxxxxxx >> Subject: Performance test result between per-vhost kthread disable and >> enable >> >> I test the performance between per-vhost kthread disable and enable. >> >> Test method: >> Send the same traffic load between per-vhost kthread disable and enable, and compare the cpu rate of host os. >> I run five vm on kvm, each of them have five nic. >> the vhost version which per-vhost kthread disable we used is rhel6 beta 2(2.6.32.60). >> the vhost version which per-vhost kthread enable we used is rhel6 (2.6.32-71). >> >> Test result: >> with per-vhost kthread disable, the cpu rate of host os is 110%. >> with per-vhost kthread enable, the cpu rate of host os is 130%. >> >> In 2.6.32.60,the whole system only have a kthread. >> [root@rhel6-kvm1 ~]# ps -ef | grep vhost root 973 2 0 Nov22 >> ? 00:00:00 [vhost] >> >> In 2.6.32.71,the whole system have 25 kthread. >> [root@kvm-4slot ~]# ps -ef | grep vhost- root 12896 2 0 10:26 >> ? 00:00:00 [vhost-12842] root 12897 2 0 10:26 ? >> 00:00:00 [vhost-12842] root 12898 2 0 10:26 ? 00:00:00 >> [vhost-12842] root 12899 2 0 10:26 ? 00:00:00 >> [vhost-12842] root 12900 2 0 10:26 ? 00:00:00 >> [vhost-12842] >> >> root 13022 2 0 10:26 ? 00:00:00 [vhost-12981] root >> 13023 2 0 10:26 ? 00:00:00 [vhost-12981] root 13024 >> 2 0 10:26 ? 00:00:00 [vhost-12981] root 13025 2 0 >> 10:26 ? 00:00:00 [vhost-12981] root 13026 2 0 10:26 ? >> 00:00:00 [vhost-12981] >> >> root 13146 2 0 10:26 ? 00:00:00 [vhost-13088] root >> 13147 2 0 10:26 ? 00:00:00 [vhost-13088] root 13148 >> 2 0 10:26 ? 00:00:00 [vhost-13088] root 13149 2 0 >> 10:26 ? 00:00:00 [vhost-13088] root 13150 2 0 10:26 ? >> 00:00:00 [vhost-13088] ... >> >> Code difference: >> In 2.6.32.60,in function vhost_init, create the kthread for vhost. >> vhost_workqueue = create_singlethread_workqueue("vhost"); >> >> In 2.6.32.71,in function vhost_dev_set_owner, create the kthread for each nic interface. >> dev->wq = create_singlethread_workqueue(vhost_name); >> >> Conclusion: >> with per-vhost kthread enable, the system can more throughput. >> but deal the same traffic load with per-vhost kthread enable, it waste more cpu resource. >> >> In my application scene, the cpu resource is more important, and one kthread for deal with traffic load is enough. >> >> So i think we should add a param to control this. >> for the CPU-bound system, this param disable per-vhost kthread. >> for the I/O-bound system, this param enable per-vhost kthread. >> the default value of this param is enable. >> >> If my opinion is right, i will give a patch for this. >> -- >> 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 >> > -- 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
