patch-2.1.22 linux/Documentation/memory.txt

• Lines: 61
• Date: Thu Jan 16 04:46:06 1997
• Orig file: v2.1.21/linux/Documentation/memory.txt
• Orig date: Thu Jan 1 02:00:00 1970

diff -u --recursive --new-file v2.1.21/linux/Documentation/memory.txt linux/Documentation/memory.txt
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+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
+	   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 
+           motherboard.
+
+	4) Linux will not currently detect above 64M of RAM, 
+	   regardless of how much memory is actually installed.
+
+All of these problems can be addressed with the "mem=XXXM" boot option
+(where XXX is the size of RAM to use in megabytes).  Adding this boot
+option to your boot loader can help Linux see more than 64M.  It can
+also tell Linux to use less memory than is actually installed.
+
+See the documentation of your boot loader (LILO, loadlin, etc.) about
+how to pass options to the kernel.
+
+There are other memory problems which Linux cannot deal with.  Random
+corruption of memory is usually a sign of serious hardware trouble.
+Try:
+
+	* Reducing memory settings in the BIOS to the most conservative 
+          timings.
+
+	* Adding a cooling fan.
+
+	* Not overclocking your CPU.
+
+	* Having the memory tested in a memory tester or exchanged
+	  with the vendor.
+	
+	* 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.
+
+
+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.