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Could you add some comments to the code? - Andreas Hansson On Aug. 28, 2015, 7:33 p.m., Joel Hestness wrote: > > ----------------------------------------------------------- > This is an automatically generated e-mail. To reply, visit: > http://reviews.gem5.org/r/3077/ > ----------------------------------------------------------- > > (Updated Aug. 28, 2015, 7:33 p.m.) > > > Review request for Default. > > > Repository: gem5 > > > Description > ------- > > Changeset 11061:a55f2523b53c > --------------------------- > sim: Don't quiesce UDelayEvents with 0 latency > > ARM uses UDelayEvents to emulate kernel __*udelay functions and speed up > simulation. UDelayEvents call Pseudoinst::quiesceNs to quiesce the system for > a specified delay. Changeset 10341:0b4d10f53c2d introduced the requirement > that any quiesce process that is started must also be completed by scheduling > an EndQuiesceEvent. This change causes the CPU to hang if an IsQuiesce > instruction is executed, but the corresponding EndQuiesceEvent is not > scheduled. > > Changeset 11058:d0934b57735a introduces a fix for uses of PseudoInst::quiesce* > that would conditionally execute the EndQuiesceEvent. ARM UDelayEvents specify > quiesce period of 0 ns (src/arch/arm/linux/system.cc), so changeset 11058 > causes these events to now execute full quiesce processes, greatly increasing > the total instructions executed in kernel delay loops and slowing simulation. > > This patch updates the UDelayEvent to conditionally execute > PseudoInst::quiesceNs (**an IsQuiesce instruction**) only if the specified > delay is >0 ns. The result is ARM delay loops no longer execute instructions > for quiesce handling, and regression time returns to normal. > > > Diffs > ----- > > src/kern/freebsd/events.cc a1c1c3aa359b > src/kern/linux/events.cc a1c1c3aa359b > > Diff: http://reviews.gem5.org/r/3077/diff/ > > > Testing > ------- > > > Thanks, > > Joel Hestness > > _______________________________________________ gem5-dev mailing list [email protected] http://m5sim.org/mailman/listinfo/gem5-dev
