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On 5/18/07, Petersson, Mats <Mats.Petersson@xxxxxxx> wrote:

> -----Original Message-----
> From: xen-users-bounces@xxxxxxxxxxxxxxxxxxx
> [mailto: xen-users-bounces@xxxxxxxxxxxxxxxxxxx] On Behalf Of
> Ashish Gupta
> Sent: 17 May 2007 23:05
> To: trilok nuwal
> Cc: Xen-users@xxxxxxxxxxxxxxxxxxx
> Subject: Re: [Xen-users] Xen scheduler setup
>
> Also, you said "As from xen documantion, boot time
> sched=credit or sedf is used to set the scheduler for the xen hosts."
> Boot time here refers to boot time of dom0 or boot time of
> the guests ?

Boot time of the entire system (which means HyperVisor + Dom0). The
Scheduler isn't per domain, but per system, so it's set up and
initialized when the system boots (it is for example responsible for
running Dom0!)

--
Mats
>
> thanks,
> Ashish
>
>
>
> On 5/17/07, Ashish Gupta <ashishgup@xxxxxxxxx> wrote:
>
>       Thanks Trilok for the clarification !
>
>       On running some of your commands I get the following
> output. Does this seem to indicate I am running the credit
> scheduler ? xm dmesg doesn't tell me.
>
>       I get the following output:
>       # xm sched-sedf
>       Name                              ID Period(ms)
> Slice(ms) Lat(ms) Extra Weight
>       Domain-0                          -1      -0.0
> -0.0    -0.0     -1     -1
>       domain1                           -1      -0.0
> -0.0    -0.0     -1     -1
>       domain2                           -1      -0.0
> -0.0    -0.0     -1     -1
>       [root@virtuoso-32 sys]#
>
>       # xm sched-credit
>       Error: No domain given.
>       Usage: xm sched-credit -d <Domain> [-w[=WEIGHT]|-c[=CAP]]
>
>       Get/set credit scheduler parameters.
>         -d DOMAIN, --domain=DOMAIN     Domain to modify
>
>         -w WEIGHT, --weight=WEIGHT     Weight (int)
>
>         -c CAP, --cap=CAP              Cap (int)
>
>
>       # xm sched-credit -d 0
>       {'cap': 0, 'weight': 256}
>
>
>
>
>       On 5/17/07, trilok nuwal < tc.nuwal@xxxxxxxxx > wrote:
>
>
>               I havent tried this, but there are two sheduler
> credit and sedf scheduler for xen host and this would be
> common for all the domains. As from xen documantion, boot
> time sched=credit or sedf is used to set the scheduler for
> the xen hosts.
>
>               For this there are two commands to set and get
> the parameters of the scheduler for individual domin
> depednding on the scheduler. Scheduler cant be differnet for
> the different domains.
>
>               #xm  sched-credit
>               #xm  sched-sedf
>
>               sched-credit         Get/set credit scheduler
> parameters.
>                sched-sedf           Get/set EDF parameters.
>
>               # xm sched-credit
>               Name                              ID Weight Cap
>               Domain-0                           0    256    0
>               os218                              7    256    0
>               # xm sched-sedf
>               Error: Xen is running with the credit scheduler
>               # xm sched-sedf --help
>               Usage: xm sched-sedf <Domain> [options]
>
>               Get/set EDF parameters.
>                 -p [MS], --period[=MS]         Relative deadline(ms)
>                 -s [MS], --slice[=MS]          Worst-case
> execution time(ms). (slice <
>                                                period)
>                 -l [MS], --latency[=MS]        Scaled period
> (ms) when domain performs
>                                                heavy I/O
>                 -e [FLAG], --extra[=FLAG]      Flag (0 or 1)
> controls if domain can run
>                                                in extra time.
>                 -w [FLOAT], --weight[=FLOAT]   CPU
> Period/slice (do not set with
>                                                --period/--slice)
>
>               # xm sched-credit --help
>               Usage: xm sched-credit [-d <Domain>
> [-w[=WEIGHT]|-c[=CAP]]]
>
>               Get/set credit scheduler parameters.
>                 -d DOMAIN, --domain=DOMAIN     Domain to modify
>                 -w WEIGHT, --weight=WEIGHT     Weight (int)
>                 -c CAP, --cap=CAP              Cap (int)
>
>
>               I dont think bvt scheduler is available in
> latest xen 3.0 ( Not sure ).
>               Hope this will be worthful to you.
>
>               Thanks,
>               -Trilok
>
>
>               On 5/17/07, Ashish Gupta < ashishgup@xxxxxxxxx
> <mailto:ashishgup@xxxxxxxxx> > wrote:
>
>                       Hi,
>
>                       I have been trying to setup Xen
> scheduling but have some questions:
>                       1. When do we exactly specify the
> scheduler to use ? At dom0 boot time (i.e. when the host
> boots) or when the domU is created with xm ?
>
>                       2. Can we change the scheduler when a
> domU is already running ?
>
>                       3. Can we change the existing scheduler
> parameters at runtime for domU or dom0 ?
>
>                       4. How do we figure out which scheduler
> is currently being used ?
>
>                       The answers are probably
> straightforward but I haven't found a tutorial or a guide
> that explains these points, esp 2,3, or 4.
>
>                       I am trying to experiment with the bvt
> scheduler and tried passing sched=bvt at xm create time. But
> I can't figure out if its actually being used or how to
> change its parameters.
>                       Any help is greatly appreciated.
>
>                       thanks,
>                       Ashish
>
>                       --
>                       http://www.cs.northwestern.edu/~agupta
> <http://www.cs.northwestern.edu/%7Eagupta>
>
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> <http://www.cs.northwestern.edu/%7Eagupta>
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