Re: [maybe-OT] GNOME/FC3 on 64-bit Athlon 64

[Alexander Larsson <alexl redhat com>]

On Fri, 2005-01-14 at 11:27 +0100, Jean Bréfort wrote:
> Le vendredi 14 janvier 2005 à 11:04 +0100, Alexander Larsson a écrit :
> > On Thu, 2005-01-13 at 12:31 -0500, Manuel Amador wrote:
> > > Hi everyone,
> > > 
> > > Well, it's been a long time since I've posted anything to these lists.
> > > Excuse me for the cross-posting, please.
> > > 
> > > Has anyone noticed the memory usage of GNOME applications under 64-bit
> > > Athlon 64?  I'm using Fedora Core 3, and I am seeing 260MB VIRT and 70MB
> > > RSS memory footprints on e.g. Evo and Nautilus.
> > 
> > Compiling for 64bit means doubling the size of all pointers. This is
> > likely to use a lot more memory. You might want to try running a 32bit
> > binary of the applications to see if this explains the memory use
> > difference.
> 
> I just made a test on two machines running gentoo linux. One is a
> Pentium4 and the other an Amd64. On the Pentium4, nautilus uses 30,9 MB
> and on the AMD64 112,7 MB which is more near four times the memory used
> with the Pentium4 than 2.
> The same is true for other apps:
> 
> 			Pentium4	Amd64
> gnome-system-monitor	21.5 MB		112.0 MB
> gnome-session		17.1 MB		85.7 MB

I got someone to run pmap on gnome-session on a fc3 x86-64 box. It seems
that it doesn't really use more memory, because the rss is about the
same, but it does use virtual memory a bit more inefficient (which might
be on purpose, after all 64bit has much more virtual memory availible).

For instance, each dlopened module seems to use at least one meg of
virtual memory:
0000002a97d71000     16K r-x--  /libpixbufloader-png.so
0000002a97d75000   1008K -----  /libpixbufloader-png.so
0000002a97e71000     16K rw---  /libpixbufloader-png.so

While on x86:
001c0000     12K r-x--  /libpixbufloader-png.so
001c3000      4K rw---  /libpixbufloader-png.so

It seems like it adds an unreadable area after each code segment to make
the whole thing use one meg of virtual memory. Maybe a security thing?

Also this looks a bit excessive:
0000002a9568a000  37744K r----  /locale-archive
vs x86:
b7dda000   2048K r----  /locale-archive

Anyway, its all virtual memory. Doesn't actually matter.

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
 Alexander Larsson                                            Red Hat, Inc 
                   alexl redhat com    alla lysator liu se 
He's an obese neurotic messiah on a mission from God. She's a provocative 
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