Hi... I am not ARM guy, but I'll see what I can share here..... hold your breath :) On Tue, May 31, 2011 at 12:54, sandeep kumar <coolsandyforyou@xxxxxxxxx> wrote: > Hi all, > The following link gives the memory map for the arm architecture. > http://www.arm.linux.org.uk/developer/memory.txt > > I have the following doubts.. > 1) Any chipset(based on arm) manufacturer(qualcom,samsung..) should follow > the same memory map. > Is it hardly constrained or can be changed? > Where are this constraints are implemented in the kernel source tree? you mean, device memory map? well AFAIK that is dictated by BIOS....kernel simply just follow along... > > 2) while i was student, i read in OS concepts that, "Virtual memory gives an > illusion to a process, > that it has always a larger continuous address space (even more than RAM) > available to it." that's true... but you need to count another limitation: addressable or not by the MMU or at least processor itself? let's say you have 16 GiB of virtual memory, composed of 4 GiB of RAM + 12 GiB swap. Theoritically, a single process should be able to use them all, but assuming we have no PAE enabled, an 32 bit system could only address up to 4 GiB > So i thought i could allocate howmuch ever memory i want. Also think about fragmentation... > But seeing the above link,i observed there is some limitation in the address > space created by the vmalloc(). > So i m now thinking that vmalloc has some limit. Yup..... maybe my old article could shed a light further for you: http://linuxdevcenter.com/pub/a/linux/2006/11/30/linux-out-of-memory.html -- regards, Mulyadi Santosa Freelance Linux trainer and consultant blog: the-hydra.blogspot.com training: mulyaditraining.blogspot.com _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
