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Ship it! There is spelling error in the patch message, 'for' and not 'fot'. - Nilay Vaish On June 15, 2015, 6:06 p.m., Andreas Hansson wrote: > > ----------------------------------------------------------- > This is an automatically generated e-mail. To reply, visit: > http://reviews.gem5.org/r/2887/ > ----------------------------------------------------------- > > (Updated June 15, 2015, 6:06 p.m.) > > > Review request for Default. > > > Repository: gem5 > > > Description > ------- > > Changeset 10879:f244ad15be32 > --------------------------- > mem: Delay responses in the crossbar before forwarding > > This patch changes how the crossbar classes deal with > responses. Instead of forwarding responses directly and burdening the > neighbouring modules in paying fot the latency (through the > pkt->headerDelay), we now queue them before sending them. > > The coherency protocol is not affected as requests and any snoop > requests/responses are still passed on in zero time. Thus, the > responses end up paying for any header delay accumulated when passing > through the crossbar. Any latency incurred on the request path will be > paid for on the response side, if no other module has dealt with it. > > As a result of this patch, responses are returned at a later > point. This affects the number of outstanding transactions, and quite > a few regressions see an impact in blocking due to no MSHRs, increased > cache-miss latencies, etc. > > Going forward we should be able to use the same concept also for snoop > responses, and any request that is not an express snoop. > > > Diffs > ----- > > src/mem/cache/cache_impl.hh ebb3d0737aa7 > src/mem/coherent_xbar.hh ebb3d0737aa7 > src/mem/coherent_xbar.cc ebb3d0737aa7 > src/mem/noncoherent_xbar.hh ebb3d0737aa7 > src/mem/noncoherent_xbar.cc ebb3d0737aa7 > src/mem/snoop_filter.hh ebb3d0737aa7 > src/mem/xbar.hh ebb3d0737aa7 > > Diff: http://reviews.gem5.org/r/2887/diff/ > > > Testing > ------- > > > Thanks, > > Andreas Hansson > > _______________________________________________ gem5-dev mailing list [email protected] http://m5sim.org/mailman/listinfo/gem5-dev
