Re: [PATCH RFC 00/49] xen: add core scheduling support

From: Juergen Gross <jgross@suse.com>
To: Dario Faggioli <dfaggioli@suse.com>, xen-devel@lists.xenproject.org
Cc: "Kevin Tian" <kevin.tian@intel.com>,
	"Stefano Stabellini" <sstabellini@kernel.org>,
	"Wei Liu" <wei.liu2@citrix.com>,
	"Jan Beulich" <jbeulich@suse.com>,
	"Konrad Rzeszutek Wilk" <konrad.wilk@oracle.com>,
	"George Dunlap" <george.dunlap@eu.citrix.com>,
	"Andrew Cooper" <andrew.cooper3@citrix.com>,
	"Tim Deegan" <tim@xen.org>,
	"Robert VanVossen" <robert.vanvossen@dornerworks.com>,
	"Julien Grall" <julien.grall@arm.com>,
	"Paul Durrant" <paul.durrant@citrix.com>,
	"Josh Whitehead" <josh.whitehead@dornerworks.com>,
	"Meng Xu" <mengxu@cis.upenn.edu>,
	"Jun Nakajima" <jun.nakajima@intel.com>,
	"Ian Jackson" <ian.jackson@eu.citrix.com>,
	"Roger Pau Monné" <roger.pau@citrix.com>
Subject: Re: [PATCH RFC 00/49] xen: add core scheduling support
Date: Sat, 30 Mar 2019 10:55:49 +0100	[thread overview]
Message-ID: <7ae32c8c-4eca-4fdb-f1a6-bf075bc9d83b@suse.com> (raw)
In-Reply-To: <8f88c0017bcd6bace30e485547efe8e982469086.camel@suse.com>

On 29/03/2019 19:16, Dario Faggioli wrote:
> Even if I've only skimmed through it... cool series! :-D
> 
> On Fri, 2019-03-29 at 16:08 +0100, Juergen Gross wrote:
>>
>> I have done some very basic performance testing: on a 4 cpu system
>> (2 cores with 2 threads each) I did a "make -j 4" for building the
>> Xen
>> hypervisor. With This test has been run on dom0, once with no other
>> guest active and once with another guest with 4 vcpus running the
>> same
>> test. The results are (always elapsed time, system time, user time):
>>
>> sched_granularity=thread, no other guest: 116.10 177.65 207.84
>> sched_granularity=core,   no other guest: 114.04 175.47 207.45
>> sched_granularity=thread, other guest:    202.30 334.21 384.63
>> sched_granularity=core,   other guest:    207.24 293.04 371.37
>>
> So, just to be sure I'm reading this properly,
> "sched_granularity=thread" means no co-scheduling of any sort is in
> effect, right? Basically the patch series is applied, but "not used",
> correct?

Yes.

> If yes, these are interesting, and promising, numbers. :-)
> 
>> All tests have been performed with credit2, the other schedulers are
>> untested up to now.
>>
> Just as an heads up for people (as Juergen knows this already :-D), I'm
> planning to run some performance evaluation of this patches.
> 
> I've got an 8 CPUs system (4 cores, 2 threads each, no-NUMA) and an 16
> CPUs system (2 sockets/NUMA nodes, 4 cores each, 2 threads each) on
> which I should be able to get some bench suite running relatively easy
> and (hopefully) quick.
> 
> I'm planning to evaluate:
> - vanilla (i.e., without this series), SMT enabled in BIOS
> - vanilla (i.e., without this series), SMT disabled in BIOS
> - patched (i.e., with this series), granularity=thread
> - patched (i.e., with this series), granularity=core
> 
> I'll do start with no overcommitment, and then move to 2x
> overcommitment (as you did above).

Thanks, I appreciate that!

Juergen

_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel