> On Jan. 21, 2015, 8:23 a.m., Andreas Hansson wrote: > > It looks sensible, but I wonder if we could not somehow move all this to > > the BaseCPU? > > > > Also, what do these states mean for an SMT? Is there a need for threadIdle > > and coreIdle?
It seems that this is a special case for cores that are supporting SMT (or codewise, have activeThreads). It also doesn't seem a noticeable performance improvement to remove 1 vtable lookup for O3CPU and InorderCPU. With SMT we can run into contention scenarios where one of the threads is suspended and the entire CPU is put to idle. This results in deadlock, as some other threads is suppose to wake up the suspended one. I am not sure if threadIdle is descriptive enough in SMT as the pipeline can be used by a different thread. I think the current terminology of active and inactive thread is much better. The term idle for a core is relevant as it means the pipeline is not executing any instruction. - Alexandru ----------------------------------------------------------- This is an automatically generated e-mail. To reply, visit: http://reviews.gem5.org/r/2607/#review5779 ----------------------------------------------------------- On Jan. 21, 2015, midnight, Alexandru Dutu wrote: > > ----------------------------------------------------------- > This is an automatically generated e-mail. To reply, visit: > http://reviews.gem5.org/r/2607/ > ----------------------------------------------------------- > > (Updated Jan. 21, 2015, midnight) > > > Review request for Default. > > > Repository: gem5 > > > Description > ------- > > Changeset 10652:1dd33bc912af > --------------------------- > O3CPU: Idle CPU status logic revised > This patch sets the CPU status to idle when the last active thread gets > suspended. > > > Diffs > ----- > > src/cpu/o3/cpu.cc a6fe75e8296b0dd2293596d11b2ac0f842b10463 > > Diff: http://reviews.gem5.org/r/2607/diff/ > > > Testing > ------- > > Tested ALPHA and X86 quick SE regressions. Also, tested ALPHA multi-program > SMT with small applications. > > > Thanks, > > Alexandru Dutu > > _______________________________________________ gem5-dev mailing list [email protected] http://m5sim.org/mailman/listinfo/gem5-dev
