A couple of performance enhancements that I use:
(1) DISABLING SWAP SPACE
Many programs run best without a swap space. With memory sizes increasing and hard
drives still rotating at the same rate they were spinning in 1998, swap spaces are
pointless (If you have the RAM... ). The question then is how to make Linux run
without a swap space since all distributions like to install them by default. (It's
funny.... I remember when the caldera disto installed a swap, but did not activate
it... The user community went nuts) Theoretically you should be able to do:
swapoff -a
Unfortunately, without a swap space, the kswapd (a tasklet) normally runs at 100%. To
eliminate this system stopper, edit linux/mm/vmscan.c. In this file, put a line that
says return 0; before it says:
/*
* Kswapd main loop.
*/
Then recompile the kernel. As a side note, I know alot of people do not want to run a
system without a swap space. However, If you've got more than 750MB of ram in your
system the chances are you're never gonna use a swap space.
(2.) ENLARGING SOUND BUFFERS
In order to improve realtime performance as related to sound, the audio buffers for
all the Linux sound drivers were reduced from 127k to 64k. For recording audio or
video (Or both at the same time as in a movie or home video) this causes dropouts. A
kernel hack is in order.
This hack is only applicable to the OSS version of the Soundblaster Live driver. Since
every sound card and every sound driver has a different implementation of buffer
schemes, you'll need to do some hunting around in the .c and .h source code files that
relate to other sound cards. But, even with other cards, if you look, you'll find it.
Anyway, for the Soundblaster live driver go to the file:
linux/drivers/sound/emu10k1/audio.c
Where is says
if (bufsize >= 0x10000)
change it to
if (bufsize > 0x40000)
In linux/drivers/sound/emu10k1/hwaccess.h
Change
#define MAXBUFSIZE 65536
to
#define MAXBUFSIZE 262144
Finally, in linux/drivers/sound/emu10k1/cardwi.h
#define WAVEIN_MAXBUFSIZE 65536
to
#define WAVEIN_MAXBUFSIZE 262144
Then recompile the kernel modules.
(3.) MAKING XFree86 FASTER
XFree86 can't display pixmap rendering very fast. The X server stalls during list box
drawing as well as during the rendering of other widgets. Fix this by adding a line to
your XF86Config* file:
In the Section "Device" area, add a line saying:
Option "XaaNoOffscreenPixmaps"
and restart the X server.
(4.) FREEING MORE MEMORY
The Linux kernel only allows for 32MB of shared memory to be allocated (by default).
Considering the price of hardware today, specically RAM, this is insane and needs to
be increased to do anything useful. Run the following command:
echo "0x7fffffff" > /proc/sys/kernel/shmmax
Please note that 0x7fffffff is about 214mb. Please adjust this value to reflect your
system and your needs.
All of the above works for me. However, as usual, you do the above at your own risk.
Best
Peck
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