Documentation/memory.txt: remove some very outdated recommendations

There are several classic problems related to memory on Linux

systems.

	1) There are some buggy motherboards which cannot properly 

	   deal with the memory above 16MB.  Consider exchanging

	   your motherboard.

	2) You cannot do DMA on the ISA bus to addresses above

	   16M.  Most device drivers under Linux allow the use

           of bounce buffers which work around this problem.  Drivers

	   that don't use bounce buffers will be unstable with

	   more than 16M installed.  Drivers that use bounce buffers

	   will be OK, but may have slightly higher overhead.

	3) There are some motherboards that will not cache above

	1) There are some motherboards that will not cache above

	   a certain quantity of memory.  If you have one of these

	   motherboards, your system will be SLOWER, not faster

	   as you add more memory.  Consider exchanging your 

If you use "mem=" on a machine with PCI, consider using "memmap=" to avoid

physical address space collisions.

See the documentation of your boot loader (LILO, loadlin, etc.) about

See the documentation of your boot loader (LILO, grub, loadlin, etc.) about

how to pass options to the kernel.

There are other memory problems which Linux cannot deal with.  Random

	  with the vendor. Consider testing it with memtest86 yourself.

	* Exchanging your CPU, cache, or motherboard for one that works.

	* Disabling the cache from the BIOS.

	* Try passing the "mem=4M" option to the kernel to limit

	  Linux to using a very small amount of memory. Use "memmap="-option

	  together with "mem=" on systems with PCI to avoid physical address

	  space collisions.

Other tricks:

	* Try passing the "no-387" option to the kernel to ignore

	  a buggy FPU.

	* Try passing the "no-hlt" option to disable the potentially

          buggy HLT instruction in your CPU.