Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: OT: P4- 3 GHz with hyper-threading

Author: Eugene Nalimov

Date: 11:13:10 10/30/02

Go up one level in this thread


ftp://download.intel.com/design/perftool/cbts/appnotes/sse2/w_spinlock.pdf

Thanks,
Eugene

On October 30, 2002 at 13:10:59, Robert Hyatt wrote:

>On October 30, 2002 at 12:33:00, Eugene Nalimov wrote:
>
>>On October 30, 2002 at 10:53:58, Robert Hyatt wrote:
>>
>>>On October 30, 2002 at 06:59:21, Terje Vagle wrote:
>>>
>>>>Hi all,
>>>>
>>>>The new cpu from intel will have a new function called
>>>>hyper-threading.
>>>>
>>>>This will make the operating system able to recognize the cpu as if it was
>>>>2 cpu's.
>>>>
>>>>Could the programs with smp-support make use of this?
>>>>
>>>>Regards,
>>>>
>>>>Terje Vagle
>>>
>>>
>>>Yes, but it is going to cause some problems.  You don't _really_ have two cpus.
>>>You
>>>have a single cpu executing two threads, and when one thread "blocks" waiting on
>>>a
>>>memory access or anything else (FP result) then the other thread will run.
>>>
>>>Spinlocks will wreck this however...
>>
>>There is special new instruction PAUSE for such a spinlocks. It is handled as
>>NOP on all existing (Intel and non-Intel) x86 CPUs prior to P4. It suspends a
>>(hyper)thread on P4 CPU for undisclosed amount of clock cycles.
>>
>>Thanks,
>>Eugene
>
>
>basically like sched_yield() does in the linux process scheduler?  Simply tells
>the
>scheduler "if you got anything else to run, run it, otherwise come back to me
>and I'll
>continue."???



This page took 0 seconds to execute

Last modified: Thu, 15 Apr 21 08:11:13 -0700

Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.