lkml.org 
[lkml]   [1997]   [Jul]   [28]   [last100]   RSS Feed
Views: [more markup]  [less markup]  [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: Interesting pentium-memcpy results
DateMon, 28 Jul 1997 13:04:55 -0400
FromBenjamin Saller Bender <>
Chris Evans <mailto:chris@ferret.lmh.ox.ac.uk> writes:
       >I just compared 2.1.46 vs. 2.1.46+pentium memcpy patch, and interestingly
    >enough found that the UNIX byte benchmarks tended to _drop_ a fair bit,
    >with the exception of process creation and execl throughput. (Note that I
    >only ran the basic 'system' tests - TCP bandwidth etc. to be determined
    >when I find the newer benchmarks)
    >

    >It does however show us that there still is performance to be gained. I
    >presume the process creation test will be using fork() which does a lot of
    >memcpy'ing of various process credentials in kernel space.
    >
   	I haven't done the research to verify how well this will work under 
Linux, but for large a memcpy on the P5 we may wanna consider using the FP 
unit using double precision read and writes. I have sample code if anyone is 
interested. 
-- 
Benjamin Saller Bender 			<case@AppliedTheory.com>
AppliedTheory Communications		Software Engineering Group
http://AppliedTheory.com/               Sentio aliquos togatos contra me conspirare.



\
 
 \ /
  Last update: 2005-03-22 13:40    [from the cache]
©2003-2008