Horton

Re: [HACKERS] Sequential scan speed, mmap, disk i/o

Thomas Lockhart <lockhart@alumni.caltech.edu>

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From: "Thomas G. Lockhart" <lockhart@alumni.caltech.edu>
To: Bruce Momjian <maillist@candle.pha.pa.us>
Cc: Michal Mosiewicz <mimo@interdata.com.pl>, hackers@postgresql.org
Date: 1998-05-16T02:40:14Z
Lists: pgsql-hackers 
> Basically, Linux is double my speed for 8k mmap'ed chunks.  Around 32k
> chunks, I get closer, and 8mb chunks are the same.  Glad to hear Linux
> has optimized mmap() recently, because BSD/OS looks much slower than
> Linux on this.

Well Bruce, don't be too happy. Most people aren't yet running the
optimized kernel; don't know if any of the benchmarks came from someone
running a bleeding-edge development version, which is what 2.1.99 would
be; first feature-freeze release in preparation for v2.2 afaik :)

And scrappy, no need to note that _all_ Linux kernels are bleeding edge
releases :)

                       - Tom (from his Linux box...)