Re: SMP Support

http://l4ka.org/projects/pistachio/

The latest release supports both AMD64, and IA64, I see no reason why  
that doesn't entail SMP support on both arches.

 From my understanding, all of those support SMP, the IA64 version  
claims that SMP works, but is not well tested.

Cheers,

-R. Tyler Ballance

On Jun 9, 2006, at 12:31 PM, Michael Emswiler wrote:

> Thanks for your prompt reply.
>
> I am really looking for answers to the following questions:
>
> 1.  Is anyone currently working on SMP for AMD64?
> 2.  Is anyone currently working on SMP for EMT64?
> 3.  If so, who should I contact so I can offer assistance?
>
> Thanks,
> MikeE
>
> On 6/9/06, R. Tyler Ballance <[email protected]> wrote:
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> This topic came up yesterday in #l4bsd on freenode, so I'll paste the
> transcript from the general "gist" of the conversation
> - ---------------------
> [11:12a] rtyler|intel: benno: how does Iguana (and in turn N1
> pistachio) handle SMP?
>
> [ snipped intermediate conversation ]
>
> [6:28p] benno​​: rtyler|intel: umm, it handles it just
> fine
> [6:38p] froody left the chat room. (Read error: 110 (Connection
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> [6:41p] ggonzahome left the chat room. (Read error: 113 (No route to
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> [6:56p] rtyler|intel​​: benno: I have no doubt about that,
> it's more of a question of how Iguana handles threads and memory in a
> multi-processor environment
> [6:57p] benno​​: how exactly do you mean? on smp
> iguana will give you the option of starting threads on different CPUs
> [6:57p] benno: iguana itself will stay single threaded
> [6:58p] benno: (as most of its operations would require holding a
> lock anyway, using IPC as the syncronising method is basically good
> enough..)
> [6:58p] rtyler|intel​​: benno: I guess just related to
> how FreeBSD does things (SMPng is my basis for any of this knowledge
> [6:58p] benno​​: no idea how freebsd does things
> [6:58p] rtyler|intel​​: i.e. 4.xx had the giant lock,
> and SMPng has brought fine-grained locking to 5.xx and 6.xx
> [6:59p] benno​​: right, iguana doesn't have fine
> grained locking, its single threadedness is basically a giant lock
> [6:59p] benno: but, you don't really call iguana nearly as often as
> you would call the bsd kernel
> [6:59p] benno: so it isn't clear that fine-grained locking would
> actually buy you anything (and in fact could have worse performance)
> [6:59p] rtyler|intel​​: but then what about services
> that it serves? do they share the same giant locking mechanism, in
> regards to the threading that iguana provides
> [7:00p] benno​​: well each server running on top of
> iguana can implement the policy it sees best
> [7:00p] benno: but really for most of them, the services then
> selves are fine grained
> [7:00p] benno: so each of these having a giant lock is kind of the
> same as having fine grained locks in a traditional kernel
> [7:01p] benno: well, not fine grained, probably coarse grained, but
> its not like the giant lock
> [7:01p] rtyler|intel​​: benno: I guess where i'm
> losing the train of thought is in that Iguana essentially operates as
> a giant lock, and provides threading to it's services, as to how
> those iguana services would run atop SMP systems
> [7:02p] benno​​: .. i need a whiteboard...
> [7:02p] benno: it is really L4 providing the smp support
> [7:02p] benno: it provides mechanisms to let you start threads and
> different CPUs
> [7:02p] benno: and migrate threads between different cpus
> - -------------------------------------------
>
>
> Hope that clears things up :)
>
> Cheers,
>
> - -R. Tyler Ballance
>
> On Jun 9, 2006, at 10:32 AM, Michael Emswiler wrote:
>
> > I am interested in Multiprocessor Support in Pistachio.
> >
> > I was wondering if anyone could point me to a link where i could
> > find current status on SMP support and what's in-progress?
> >
> > I am primarily interested in EMT64 and AMD64.
> >
> > Thanks,
> > MikeE
> >
> >
>
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