X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=Documentation%2Fmemory.txt;h=2b3dedd39538f0101467b52c821829924dd10adb;hb=6a77f38946aaee1cd85eeec6cf4229b204c15071;hp=7af1709e8facbd55b7c633c5fc173723f9f0668b;hpb=87fc8d1bb10cd459024a742c6a10961fefcef18f;p=linux-2.6.git

diff --git a/Documentation/memory.txt b/Documentation/memory.txt
index 7af1709e8..2b3dedd39 100644
--- a/Documentation/memory.txt
+++ b/Documentation/memory.txt
@@ -21,6 +21,8 @@ systems.
 All of these problems can be addressed with the "mem=XXXM" boot option
 (where XXX is the size of RAM to use in megabytes).  
 It can also tell Linux to use less memory than is actually installed.
+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
 how to pass options to the kernel.
@@ -44,7 +46,9 @@ Try:
 	* 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.
+	  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: