Hi Andreas,

Thanks for your reply. I am trying to figure out how to implement this
based on your inputs. Can you also please point out the data structures
which maintains the queue in cross bar.?

Thanks,
Prathap

On Mon, May 4, 2015 at 4:04 PM, Andreas Hansson <andreas.hans...@arm.com>
wrote:

>  Hi Prathap,
>
>  The most sensible place to implement the arbitration is indeed in the
> crossbar which is conceptually part of the L2 cache. By default the
> crossbar uses First-Come First-Served, but you can change with not too much
> coding. The tricky bit in this case is to base the selection on MSHRs,
> since the crossbar has no such accounting. I would think the easiest is to
> add outstanding transaction counting per SlavePort in the crossbar, and
> then only let a port have X outstanding transactions. Overall this would be
> valuable functionality, so if you do code it up, please post a patch. It
> would be a great contribution.
>
>  Andreas
>
>   From: Prathap Kolakkampadath <kvprat...@gmail.com>
> Reply-To: gem5 users mailing list <gem5-users@gem5.org>
> Date: Monday, 4 May 2015 20:18
> To: gem5 users mailing list <gem5-users@gem5.org>
> Subject: [gem5-users] Query regarding blocking cache slave port
>
>   Hello All,
>
>  I am simulating an ARM O3 multi-core system with private L1 cache and a
> Shared L2 cache.
> I am investigating the MSHR contention in the L2 cache. If cache has no
> free MSHRs, this Marks the access path of the cache as blocked and also
> sets the blocked flag in the slave interface.This means there won't be any
> further access to the L2 cache.
> Instead of blocking the L2 cache altogether, i would like to place a MSHR
> reservation to a selected core. So that requests from only selected core
> are blocked based on its respective MSHR utilization.
>
>  I am not sure if this is feasible. Do L2 Bus has an arbitrator which can
> be modified to do this?
>
>  Thanks,
>  Prathap
>
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