Re: [RFC PATCH 0/4] Gang scheduling in CFS

[Avi Kivity]

On 12/27/2011 12:10 PM, Nikunj A Dadhania wrote:
> On Tue, 27 Dec 2011 11:51:46 +0200, Avi Kivity <avi@xxxxxxxxxx> wrote:
> > On 12/27/2011 11:44 AM, Nikunj A Dadhania wrote:
> > > > > I am seeing a drop of ~44% when setting yield_on_hlt = 0
> > > > >
> > > > 
> > > > A drop of 44% of what?
> > > > 
> > > records/sec
> > >
> > > Ebizzy - 2VM running in parallel, both having gang scheduling enabled.
> > >
> > >                     yield_on_hlt=1         yield_on_hlt=0
> > >  EbzyRecords/sec      41955.50               23285.00            -44 
> > >
> > >
> > 
> > Interesting, are you overcommitting vcpus?
> > 
> Yes(1:2). On a 8cpu machine, have 2VMs running, which is 8vcpus each.

Ah, yield_on_hlt=0 isn't any good with overcommit.  The vcpu stays
scheduled when idle, so other vcpus don't get to use its cpu time.

-- 
error compiling committee.c: too many arguments to function

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