On Mon, Dec 21, 2009 at 12:22:09PM -0600, Joel Schopp wrote: > 4 is the new 2. Since the actual threads per core is unknown at > this point in boot you have to be conservative and go with the > maximum number of any processor. See page 4 of these charts: > http://www.power.org/events/powercon09/taiwan09/IBM_Overview_POWER7.pdf
Sure P7 /can/ be 4-way SMT, but consider the case where you know you have 128 threads so you set NR_CPUS to 128, then you boot with "max cores" of 32, so you lose half of your threads. I guess that's only a problem when you build your own kernels, distros are probably setting NR_CPUS high enough to cover all SMT2 systems anyway. I guess if the patch only set the "max cores" and described why, I'd (FWIW :D) be more comfortable. Yours Tony _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
