From mboxrd@z Thu Jan 1 00:00:00 1970 From: htmldeveloper@gmail.com (Peter Teoh) Date: Tue, 31 May 2011 23:27:00 +0800 Subject: Can i allocate 4GB virtual addresses (more than a certain limit) using vmalloc? In-Reply-To: References: Message-ID: To: kernelnewbies@lists.kernelnewbies.org List-Id: kernelnewbies.lists.kernelnewbies.org To answer your subject: I think the straight answer is "no". Many reason, among them: ARM is still 32-bit, at least at the present moment: http://www.google.com/search?q=does+arm+have+64bit&num=100 so with hardware 32-bit based, doing MMU at the 64-bit level is still not possible (without the MMU 64-bit hardware architecture, I don't think it is possible to do any >4GB memory translation stuff. Am I not wrong? On Tue, May 31, 2011 at 1:54 PM, sandeep kumar 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? > > 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." > So i thought i could allocate howmuch ever memory i want. > 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. > > Please make me clear these things.... > > > With regards, > Sandeep Kumar Anantapalli, > > _______________________________________________ > Kernelnewbies mailing list > Kernelnewbies at kernelnewbies.org > http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies > > -- Regards, Peter Teoh