斗 长 Symmetric Multiprocessing(SMP ￥斗 ★★ o No master processor All the processors share just one memory space Interrupts can be serviced on any processor Any processor can cause another processor to reschedule what its running o Maximum of cPUs stored in registry HKLM\ System\ Current ControlSet\ Control\ Session Manager\ Licensed Processors
36 Symmetric Multiprocessing (SMP) No master processor – All the processors share just one memory space – Interrupts can be serviced on any processor – Any processor can cause another processor to reschedule what it’s running Maximum # of CPUs stored in registry – HKLM\System\CurrentControlSet\Control\Session Manager\LicensedProcessors
★ Symmetric Multiprocessing(SMP ￥斗 ★★ s Current implementation limit is of bits in a native word 32 processors for 32-bit systems 64 processors for 64-bit systems CPUs Not an architectural limit just implementation Cache Memory SMP 37
37 Memory I/O CPUs L2 Cache SMP Symmetric Multiprocessing (SMP) Current implementation limit is # of bits in a native word – 32 processors for 32-bit systems – 64 processors for 64-bit systems – Not an architectural limit – just implementation
★ “长 Hyperthreading ￥斗 ★★ o New technology in newer Xeon Pentium 4 processors Makes a single processor appear as a dual processor to OS Also called simultaneous multithreading technology sMT) o Chip maintains two separate cpu states logical processors” Execution engine onboard cache is shared
38 Hyperthreading New technology in newer Xeon & Pentium 4 processors – Makes a single processor appear as a dual processor to OS – Also called simultaneous multithreading technology (SMT) Chip maintains two separate CPU states – “logical processors” – Execution engine & onboard cache is shared
斗 长 Hyperthreading ￥斗 ★★ o Works with Windows 2000, but only XP Server 2003 are hyperthreading aware” o Logical processors don 't count against physical processor limits o Scheduling algorithms take into account logical vs physical processors Applications can also optimize for it(new Windows function in Server 2003)
39 Hyperthreading Works with Windows 2000, but only XP & Server 2003 are “hyperthreading aware” Logical processors don’t count against physical processor limits Scheduling algorithms take into account logical vs physical processors – Applications can also optimize for it (new Windows function in Server 2003)
斗 长 Hyperthreading ￥斗 ★★ Four logical processors 12 Two physical processors
40 Hyperthreading 1 2 3 4 Four logical processors Two physical processors