I have a CentOS 5.2 Dual-Core Host with two domU''s. One domU is for apache and postfix, the other one is just for BOINC. I thought that I can configure the XEN credit scheduler in such a manner, that the BOINC domU only gets CPU resources if the other one, the "important" one, has nothing else to do. After a "xm sched-credit -d boinc -w 1" and "xm sched-credit -d web -w 200" I run a CPU benchmark on the "web" domU. I expected that the "web" domU would get 199% CPU share and the boinc domU just 1%, because the "web" domU hast 200 times more weight than the BOINC domU. But the credit scheduler gave both domU''s about 100% CPU share. What am I missing here? xm dmesg shows "(XEN) Using scheduler: SMP Credit Scheduler (credit)" and "xm sched_credit -d web" also confirms that the weight is set correctly. Regards Florian _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Just a wild guess, but do both domUs have single VCPUs with a different CPU assigned? It seems reasonable to assume that the domUs would have to be using the same CPU(s) in order for the priority to come into play. Assuming I am correct there, they should have the same CPU assigned if they are using one VCPU; if they are using two VCPUs then they should each be using both CPUs anyway, and in either of the aforementioned scenarios, the priority should come in to play. Dustin -----Original Message----- From: xen-users-bounces@lists.xensource.com [mailto:xen-users-bounces@lists.xensource.com] On Behalf Of Florian Schmaus Sent: Monday, December 01, 2008 10:24 To: xen-users@lists.xensource.com Subject: [Xen-users] Credit Scheduler I have a CentOS 5.2 Dual-Core Host with two domU''s. One domU is for apache and postfix, the other one is just for BOINC. I thought that I can configure the XEN credit scheduler in such a manner, that the BOINC domU only gets CPU resources if the other one, the "important" one, has nothing else to do. After a "xm sched-credit -d boinc -w 1" and "xm sched-credit -d web -w 200" I run a CPU benchmark on the "web" domU. I expected that the "web" domU would get 199% CPU share and the boinc domU just 1%, because the "web" domU hast 200 times more weight than the BOINC domU. But the credit scheduler gave both domU''s about 100% CPU share. What am I missing here? xm dmesg shows "(XEN) Using scheduler: SMP Credit Scheduler (credit)" and "xm sched_credit -d web" also confirms that the weight is set correctly. Regards Florian _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Both domUs have 2 VCPUs: Name ID VCPUs CPU State Time(s) CPU Affinity Domain-0 0 0 0 r-- 1738.8 0 Domain-0 0 1 1 -b- 532.0 1 web 6 0 1 r-- 422829.0 any cpu web 6 1 0 --- 422758.0 any cpu boinc 2 0 0 -b- 5096.9 any cpu boinc 2 1 1 -b- 928.2 any cpu Florian Dustin Henning wrote:> Just a wild guess, but do both domUs have single VCPUs with a > different CPU assigned? It seems reasonable to assume that the domUs would > have to be using the same CPU(s) in order for the priority to come into > play. Assuming I am correct there, they should have the same CPU assigned > if they are using one VCPU; if they are using two VCPUs then they should > each be using both CPUs anyway, and in either of the aforementioned > scenarios, the priority should come in to play. > Dustin > > -----Original Message----- > From: xen-users-bounces@lists.xensource.com > [mailto:xen-users-bounces@lists.xensource.com] On Behalf Of Florian Schmaus > Sent: Monday, December 01, 2008 10:24 > To: xen-users@lists.xensource.com > Subject: [Xen-users] Credit Scheduler > > I have a CentOS 5.2 Dual-Core Host with two domU''s. One domU is for > apache and postfix, the other one is just for BOINC. I thought that I > can configure the XEN credit scheduler in such a manner, that the BOINC > domU only gets CPU resources if the other one, the "important" one, has > nothing else to do. > After a "xm sched-credit -d boinc -w 1" and "xm sched-credit -d web -w > 200" I run a CPU benchmark on the "web" domU. I expected that the "web" > domU would get 199% CPU share and the boinc domU just 1%, because the > "web" domU hast 200 times more weight than the BOINC domU. But the > credit scheduler gave both domU''s about 100% CPU share. > What am I missing here? > > xm dmesg shows "(XEN) Using scheduler: SMP Credit Scheduler (credit)" > and "xm sched_credit -d web" also confirms that the weight is set correctly. > > Regards > Florian > > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users > > > > >_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users