Author: Robert Hyatt
Date: 22:01:08 03/07/03
Go up one level in this thread
On March 07, 2003 at 23:44:04, Keith Evans wrote: >On March 07, 2003 at 23:27:09, Robert Hyatt wrote: > >>On March 07, 2003 at 10:27:50, Keith Evans wrote: >> >>>On March 06, 2003 at 16:59:34, Robert Hyatt wrote: >>> >>>>On March 06, 2003 at 16:36:15, Robert Hyatt wrote: >>>> >>>>Here is some additional profile data. This is a couple of weeks old, but it was >>>>produced by >>>>running the "bench" command so anyone should be able to reproduce these numbers >>>>using >>>>whatever compiler they want. I used gcc as the person that asked for this data >>>>a couple of >>>>weeks ago was also using gcc and I thought it easier to keep the same compiler >>>>for both of >>>>us. >>>> >>>> 5.27 46.72 5.56 24487027 0.00 0.00 HashProbe >>>> 0.81 95.91 0.85 19234964 0.00 0.00 HashStore >>>> >>>>This is using the 6 benchmark positions which has a couple of endgame positions >>>>that >>>>makes hashing more important. Total = 6.08%. If you eliminate hashing totally, >>>>the >>>>program will go from 2.16M NPS to 2.16/.9392 which is a grand total of 2.3M >>>>nodes >>>>per second, a _far_ cry from that 3M you were talking about. >>>> >>>>_your_ hash overhead might be 33%, but mine is not. >>>> >>>>I have no idea where you get your numbers from, but it is _clear_ that you don't >>>>get >>>>'em from computers... >>>> >>>>For anyone wanting to produce the above numbers, compile crafty with -pg for CC >>>>and CX >>>>flags (in addition to other options as already used) and add -pg to the LD >>>>options as well. >>>>Compile it using the Makefile you just modified, then type "crafty" "bench" and >>>>when it >>>>finishes "end". Then type "gprof crafty" and you'll see the percent of the time >>>>spent in each >>>>distinctly named procedure... >>>> >>>>Simple. Easy. More accurate than guesswork and hand-waving. >>> >>>In case this matters... >>> >>>What Linux distribution are you running? Is there anything to watch out for >>>when setting up a box to support HT besides BIOS settings? >>> >>>Regards, >>>Keith >> >> >>I use redhat. 8.0 at the moment. No particular reason other than Ingo (Molnar) >>and I were working on a SMP bug on an ALR box I used to have (quad pentium pro >>box several years ago) and I switched to Red Hat as that was what he was >>running, and it made life easier as we exchanged kernel executables over the >>net. >> >>Nothing to worry about other than the current 2.4 kernels recognize hyper- >>threading, but they are not "optimized" for it yet. IE if you run two compute- >>bound processes, you might get both on one physical or one on each physical >>CPU, and it is based on basically random luck. This will be fixed in future >>versions, and has been fixed in patches for some of the developmental kernels >>(2.5.x) > >Thanks for the information. Hopefully we'll some new dual Xeon boxes at work >fairly soon and I can give it a try. Good way to break it in before doing >serious >ASIC development on it. > >I'll probably be running RedHat 7.2 since that's what Synopsys officially >supports >and if you run anything else they don't like to support you. That's using >a 2.4.18 kernel which I hope is considered current. > >Regards, >Keith I've been running 2.4.20 for a long while now. 2.4.21 is pretty close to being released if it has not already. I _think_ 2.4.18 was the first to support SMT.
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