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From:Jeremy Zawodny Date:January 17 2002 11:19pm
Subject:Re: Memory
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On Thu, Jan 17, 2002 at 05:06:07PM -0600, Dan Nelson wrote:
> In the last episode (Jan 17), Jeremy Zawodny said:
> > On Thu, Jan 17, 2002 at 04:37:40PM +0200, Heikki Tuuri wrote:
> > > The maximum process space of Linux x86 is 2 GB, and better play
> > > safe.
> > > 
> > > Jeremy, I think some Intel x86 processors support segmented memory
> > > above > 4 GB. Is that supported in Linux?
> > 
> > Not sure.  Most of what I've heard has always come back to the 2GB
> > limit for a single process.  There's probably some discussion of it
> > in the linux-kernel archives.
> 
> You can shift the kernel/userland split point; make it 3gb userland,
> 1gb kernel, but you probably don't want to go any more than that.
> 
> Oracle has used multiple shared memory segments to allow a single
> process to access more than 4GB of memory on a 32-bit machines for
> years.  You allocate (say) 10 600MB segments, but only map two in at
> a time.  This approach wouldn't work well for Mysql since it's a
> single process.  Threads all share the same address space, so all
> the threads would have to agree on which 2 segments to use at any
> point in time.

Well, it's a good thing that affordable 64 bit hardware is on the
way... :-)
-- 
Jeremy D. Zawodny, <jzawodn@stripped>
Technical Yahoo - Yahoo Finance
Desk: (408) 349-7878   Fax: (408) 349-5454   Cell: (408) 685-5936

MySQL 3.23.41-max: up 14 days, processed 347,170,435 queries (267/sec. avg)
Thread
MemoryJohn Kemp17 Jan
  • Re: MemoryJeremy Zawodny17 Jan
Re: MemoryHeikki Tuuri17 Jan
  • Re: MemoryJohn Kemp17 Jan
  • Re: MemoryJeremy Zawodny17 Jan
    • Re: MemoryDan Nelson18 Jan
      • Re: MemoryJeremy Zawodny18 Jan
Re: Memoryalec.cawley17 Jan
Re: MemoryHeikki Tuuri17 Jan