Re: [Gems-users] state transitions in MOESI

[Mike Marty <mikem@xxxxxxxxxxx>]

Thats right-- many of our protocols do not implement an UPGRADE 
request.  Feel free to add it.  It is simple to do but I don't think it 
makes a big difference in practice.  Especially with any protocol that 
implements the E-state.
--Mike (back from vacation)

Dave Z. wrote:
> But that's not the case in MOESI_SMP_hammer.
>
> Thanks,
>
> Dave
>
> ----- Original Message ----
> From: hongxia sun <sunhx.seraph@xxxxxxxxx>
> To: Gems Users <gems-users@xxxxxxxxxxx>
> Sent: Monday, April 9, 2007 6:05:03 PM
> Subject: Re: [Gems-users] state transitions in MOESI
>
> If some data in the cache is in S state, then the store event should 
> send UPGRADE rather than GETX to the owner.
> 2007/4/10, Dave Z. <zhu_dave@xxxxxxxxx <mailto:zhu_dave@xxxxxxxxx>>:
>
>     Other than store events in S state, store events in O
>     state trigger GETX events as well. I would say the
>     idea is to invalidate the other copies, but when a
>     GETX request is received, the local copy is sent to
>     the requestor. So, I still don't undertand why it's an
>     exclusive data request rather than an invalidation
>     message?
>
>     Thanks,
>
>     Dave
>
>
>     --- "Datta, Kushal" <kdatta@xxxxxxxx <mailto:kdatta@xxxxxxxx>> wrote:
>
>     >
>     > Well, since the data is in the O State in P0, most
>     > probably it is updating the data (P0->store).
>     > So, although P1 has the data in S state in its
>     > cache,
>     > it does not have the most-recent value. So P1 needs
>     > to get the data from P0.
>     >
>     > Thanks and regards,
>     > Kushal.
>     > Graduate Student,
>     > Department of ECE,
>     > UNC Charlotte.
>     >
>     >
>     >
>     > -----Original Message-----
>     > From: gems-users-bounces@xxxxxxxxxxx
>     <mailto:gems-users-bounces@xxxxxxxxxxx> on behalf of
>     > Dave Z.
>     > Sent: Mon 4/9/2007 1:29 PM
>     > To: Gems Users
>     > Subject: Re: [Gems-users] state transitions in MOESI
>     >
>     > Hello,
>     >
>     > Let me correct my question. If some data is in S
>     > state
>     > in the cache, on a store event: GETX event is sent
>     > to
>     > the owner directory. The directory then sends the
>     > data
>     > to the requesting cache. Why is it necessary to
>     > acquire the data when the cache already has it in S
>     > state?
>     >
>     > Thank you,
>     >
>     > Dave
>     >
>     >
>     > --- "Dave Z." <zhu_dave@xxxxxxxxx <mailto:zhu_dave@xxxxxxxxx>>
>     wrote:
>     >
>     > > Hello,
>     > >
>     > > I have a question regarding the state transitions
>     > in
>     > > MOESI-hammer (perhaps the same scenario exists in
>     > > other protocols as well). Let's say we have two
>     > > processors: P0 and P1 that share some data. P0 is
>     > > the owner, so the data is in O state in P0 and in
>     > S
>     > > state in P1. If P1 tries to write to the data,
>     > GETX
>     > > will be issued. P0 sees the Other_GETX event and
>     > > sends the data back to P1, right? If so, why is
>     > > there a need to send the data even though P1 has
>     > the
>     > > data in S state?
>     > >
>     > > Thank you,
>     > >
>     > > Dave
>     > >
>     > >
>     > >
>     > >
>     > >
>     > >
>     >
>     ____________________________________________________________________________________
>     > > Looking for earth-friendly autos?
>     > > Browse Top Cars by "Green Rating" at Yahoo! Autos'
>     > > Green Center.
>     > > http://autos.yahoo.com/green_center/
>     > > _______________________________________________
>     > > Gems-users mailing list
>     > > Gems-users@xxxxxxxxxxx <mailto:Gems-users@xxxxxxxxxxx>
>     > >
>     >
>     https://lists.cs.wisc.edu/mailman/listinfo/gems-users
>     <https://lists.cs.wisc.edu/mailman/listinfo/gems-users>
>     > > Use Google to search the GEMS Users mailing list
>     > by
>     > > adding
>     > >
>     > "site:https://lists.cs.wisc.edu/archive/gems-users/
>     <https://lists.cs.wisc.edu/archive/gems-users/>"
>     > > to your search.
>     > >
>     > >
>     >
>     >
>     >
>     >
>     >
>     ____________________________________________________________________________________
>     > Be a PS3 game guru.
>     > Get your game face on with the latest PS3 news and
>     > previews at Yahoo! Games.
>     > http://videogames.yahoo.com/platform?platform=120121
>     > _______________________________________________
>     > Gems-users mailing list
>     > Gems-users@xxxxxxxxxxx <mailto:Gems-users@xxxxxxxxxxx>
>     >
>     https://lists.cs.wisc.edu/mailman/listinfo/gems-users
>     > Use Google to search the GEMS Users mailing list by
>     > adding
>     > "site:https://lists.cs.wisc.edu/archive/gems-users/
>     <https://lists.cs.wisc.edu/archive/gems-users/>"
>     > to your search.
>     >
>     >
>     > > _______________________________________________
>     > Gems-users mailing list
>     > Gems-users@xxxxxxxxxxx <mailto:Gems-users@xxxxxxxxxxx>
>     >
>     https://lists.cs.wisc.edu/mailman/listinfo/gems-users
>     > Use Google to search the GEMS Users mailing list by
>     > adding
>     > "site: https://lists.cs.wisc.edu/archive/gems-users/";
>     > to your search.
>     >
>     >
>
>
>
>
>     ____________________________________________________________________________________
>
>     Get your own web address.
>     Have a HUGE year through Yahoo! Small Business.
>     http://smallbusiness.yahoo.com/domains/?p=BESTDEAL
>     _______________________________________________
>     Gems-users mailing list
>     Gems-users@xxxxxxxxxxx <mailto:Gems-users@xxxxxxxxxxx>
>     https://lists.cs.wisc.edu/mailman/listinfo/gems-users
>     Use Google to search the GEMS Users mailing list by adding
>     "site:https://lists.cs.wisc.edu/archive/gems-users/"; to your search.
>
>
> _______________________________________________
> Gems-users mailing list
> Gems-users@xxxxxxxxxxx
> https://lists.cs.wisc.edu/mailman/listinfo/gems-users
> Use Google to search the GEMS Users mailing list by adding 
> "site:https://lists.cs.wisc.edu/archive/gems-users/"; 
> <https://lists.cs.wisc.edu/archive/gems-users/%22>; to your search.
>
>
> ------------------------------------------------------------------------
> Need Mail bonding?
> Go to the Yahoo! Mail Q&A 
> <http://answers.yahoo.com/dir/index;_ylc=X3oDMTFvbGNhMGE3BF9TAzM5NjU0NTEwOARfcwMzOTY1NDUxMDMEc2VjA21haWxfdGFnbGluZQRzbGsDbWFpbF90YWcx?link=ask&sid=396546091> 
> for great tips from Yahoo! Answers 
> <http://answers.yahoo.com/dir/index;_ylc=X3oDMTFvbGNhMGE3BF9TAzM5NjU0NTEwOARfcwMzOTY1NDUxMDMEc2VjA21haWxfdGFnbGluZQRzbGsDbWFpbF90YWcx?link=ask&sid=396546091> 
> users.
> ------------------------------------------------------------------------
>
> _______________________________________________
> Gems-users mailing list
> Gems-users@xxxxxxxxxxx
> https://lists.cs.wisc.edu/mailman/listinfo/gems-users
> Use Google to search the GEMS Users mailing list by adding "site:https://lists.cs.wisc.edu/archive/gems-users/"; to your search.
>
>