Thanks for the responses... I could not find exact information at http://www.skynet.ie/~mel/projects/vm/ (i could not go through all of the document. i think i should buy the book for the up to date information , anyways.) But I found exact info at http://www.redhat.com/magazine/001nov04/features/vm/ There it tells exactly what kscand does ? Now , i am not afraid of it ;) Thanks again... "Fawad Lateef" <fawadlateef@xxxxxxxxx> wrote in message news:1e62d1370512261926y1806b186n5a7278ff7fad696@xxxxxxxxxxxxxxxxx On 12/27/05, Rik van Riel <riel@xxxxxxxxxxx> wrote: > On Mon, 26 Dec 2005, Malkocoglu wrote: > > > I saw a server with 6GB ram installed on an x86_32 > > machine running Linux RedHat 7.3 with Kernel 2.4. > > There was a process called kscand which ate lots of CPU. > > > > After some search , i found out that this kernel process swaps > > the memory regions below 4GB to and from the upper region. > > Sorry, but that's simply not true. > > > What is the behaviour of Kernel 2.6 for this case running on an > > x86_32 with more than 4GB ram ? does ksacnd hack still exist ? > > Also , is this behaviour true for exact 4GB ram machines too ? > > The behaviour you describe is not true for any Linux kernel. > > The 4GB limitation is one of virtual memory, but physical > memory can be larger than that. > Adding one more thing ! For complete understanding of how it works especially in Linux do read "Understanding the Linux VM by Mel Gorman" (just google for it) and you can also read previous mail threads on kernelnewbies; topic is Kernel Address Space or like so in which Highmemory was discussed in detail. I think this is the thread (http://mail.nl.linux.org/kernelnewbies/2005-09/msg00005.html) -- Fawad Lateef -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/ -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
