On Wed, Jan 09, 2002 at 06:44:58PM +0200, Hilik Stein wrote: > i was trying to understand the information in /proc/meminfo, to no avail. > I am running a linux kernel 2.4.3 Ouch, that's old. > i have a working system here, where i see that the amount of free memory > keeps dropping constantly, and never goes back up, i understood that it > could be that the memory was going into some memory caches, can someone > please explain how i can locate the missing memory ? /proc/meminfo shows you (in Buffers and Cached), and you can also use the "free" utility. > another thing that i failed to understand is the difference between low > memory and high memory. what applications are using which type of memory ? > what happens when i run out of either of low or high memory ? High memory only matters if you have >4GB in your machine (on x86). The CPU can't address all of the 4GB, so all the memory above the 4GB is called high memory. > i also heard that the memory management has been greatly improved after > 2.4.7, what has changed so much ? The bugs just got fixed. In my opinion the VM in 2.4.17 is still not good, especially with lots of disk IO going on (you really don't want to be using the machine for interactive stuff with updatedb running in the background). I prefer to use Rik van Riel's rmap VM which has a much smoother behaviour, especially during disk IO (like importing kernels to a local CVS tree). See http://www.surriel.com/patches/ . > any pointers to where i can learn more about this memory management scheme > would be greatly appreciated. See http://linux-mm.org/ . Erik -- J.A.K. (Erik) Mouw, Information and Communication Theory Group, Faculty of Information Technology and Systems, Delft University of Technology, PO BOX 5031, 2600 GA Delft, The Netherlands Phone: +31-15-2783635 Fax: +31-15-2781843 Email: J.A.K.Mouw@its.tudelft.nl WWW: http://www-ict.its.tudelft.nl/~erik/ -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ IRC Channel: irc.openprojects.net / #kernelnewbies Web Page: http://www.kernelnewbies.org/
