Hi all,
I am just trying to understand the credit scheduler in xen.
please correct me in below sequence .
There are four VMs named V1 to V4. each having 256 credits. t is the CPU
time.
V1 V2
V3 V4
t=0 256 256
256 256
t=10 156 256
256 256
t=20 56 256
256 256
t=30 -44 256
256 256
t=40 -44 156
256 256
t=50 -44 56
256 256
t=60 -44 -44
256 256
t=70 -44 -44
156 256
t=80 -44 -44
56 256
t=90 -44 -44 -44
256
t=100 -44 -44
-44 156
t=110 -44 -44
-44 56
t=120 -44 -44 -44
-44
Credits will be re assigned when some of all credits becomes negative.
what I understand from the BOOST state is. According to I/O event mapping in
event channel, if the domain corresponding to that I/O event is in UNDER
state than it can be upgraded to BOOST state which is highest priority state
in xen.
So currently running domain will be preempted and BOOSTED domain will
receive the CPU.
I am having some questions
(1) How many credits are deducted from a VM in a BOOSTed state?
(2) If a VM has the work only for 10 ms, then what happens? Will it go to
idle state? after 10 secs or it will consume whole 30 secs slice?
Please provide me the direction.
Regards
Gaurav somani
Dhirubhai Ambani Institute of ICT,
Gandhinagar
Gujarat, INDIA
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Hi~ Gaurav Somani wrote:> > Hi all, > > > I am just trying to understand the credit scheduler in xen. > please correct me in below sequence . > There are four VMs named V1 to V4. each having 256 credits. t is the CPU > time. > > > V1 V2 > V3 V4 > > t=0 256 256 > 256 256 > t=10 156 256 > 256 256 > t=20 56 256 > 256 256 > t=30 -44 256 > 256 256 > > t=40 -44 156 > 256 256 > t=50 -44 56 > 256 256 > t=60 -44 -44 > 256 256 > > t=70 -44 -44 > 156 256 > t=80 -44 -44 > 56 256 > t=90 -44 -44 -44 > 256 > > t=100 -44 -44 > -44 156 > t=110 -44 -44 > -44 56 > t=120 -44 -44 -44 > -44 > > Credits will be reassigned when some of all credits becomes negative. > IS WRONG. Scheduler will do it every 30ms > what I understand from the BOOST state is. According to I/O event mapping > in > event channel, if the domain corresponding to that I/O event is in UNDER > state than it can be upgraded to BOOST state which is highest priority > state > in xen. > So currently running domain will be preempted and BOOSTED domain will > receive the CPU. > > I am having some questions > (1) How many credits are deducted from a VM in a BOOSTed state? the > same as other state > (2) If a VM has the work only for 10 ms, then what happens? Will it go to > idle state? after 10 secs or it will consume whole 30 secs slice? > former is right , I think > > Please provide me the direction. > > Regards > > Gaurav somani > Dhirubhai Ambani Institute of ICT, > Gandhinagar > Gujarat, INDIA > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xensource.com > http://lists.xensource.com/xen-devel > >-- View this message in context: http://www.nabble.com/Credit-Scheduler-tp23874583p24161521.html Sent from the Xen - Dev mailing list archive at Nabble.com. _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel