Re: Swap or I/O Improvement in Fedora 8?

On Wed, 27 Feb 2008 01:33:45 +0800, LaBird wrote:

Hi,

"General Schvantzkopf" <schvantzkopf@xxxxxxxxx> wrote in message
news:Rr2dnfrmLsM6xF7anZ2dnUVZ_gidnZ2d@xxxxxxxxxxxxxx

When you do a free how much of your swap space is used with F7 and F8?


Thanks for your help first.
Do you mean after running the program? I need to collect it then. When I
boot up using the same machine (Athlon64 Dual Core), both versions do
not eat up any swap space, but the memory usage is different:

F7(64-bit):
Mem: (Total) 1930264 (Used) 237968 (Free) 1692296 (Shared) 0 (Buffers)
11264 (Cached) 120424
-/+ buffers/cache: (Used) 106280 (Free) 1823984 Swap: (Total) 33551712
(Used) 0 (Free) 33551712

F8(64-bit):
Mem: (Total) 1933196 (Used) 127240 (Free) 1805956 (Shared) 0 (Buffers)
7696 (Cached) 46952
-/+ buffers/cache: (Used) 72592 (Free) 1860604 Swap: (Total) 33551712
(Used) 0 (Free) 33551712

Both are booted using runlevel 3, but seems the values do change every
time, except for the swap usage.

Best Regards,
LaBird (Benny).
[Email: Remove all underscores to get the correct address.]

Yes I mean when running the program, if you were using any swap space
after a boot it would be game over.

Swapping is a function of the kernel and both F7 and F8 are running a
2.6.23 kernel. It's possible that there is some patch that they've
applied to the F8 kernel that changes the memory management algorithm.

An experiment that you could try is to use your own kernel. Download the
latest kernel from kernel.org then copy the .config file from

/usr/src/kernels/2.6.23.15-137.fc8-x86_64/.config

do a

make gconfig
which will bring up the configuration GUI and let you make any changes
that you want.

Then do

make -j 2
make modules_install
make install

Do it on both F7 and F8. This will give you identical kernels on both
systems. You could also try the 2.6.24 kernel vs a 2.6.23, it's possible
that RH used a memory management patch on the 2.6.23 F8 kernel that's now
in the mainstream .24 kernel.
.

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