On Wed, Sep 10, 2014 at 5:52 PM, Manavendra Nath Manav <mnm.kernel@xxxxxxxxx> wrote: > > On 10-Sep-2014 6:24 pm, <Valdis.Kletnieks@xxxxxx> wrote: >> >> On Wed, 10 Sep 2014 14:45:23 +0530, Manavendra Nath Manav said: >> >> > But if the total RAM is limited (less than 896MB LOWMEM), for example as >> > in >> > embedded devices how the kernel code be kept in RAM all the time. Am I >> > correct to assume that the kernel pre-fetches all pages when entering >> > kernel mode from user mode? >> >> No, kernel code is loaded by your boot loader, and *it stays there*. >> Similarly, >> if you modprobe something, the kernel allocates the page, loads the code, >> and leaves it there. >> >> Particularly in embedded devices, where you know all the modules the >> kernel may >> need, it's common to just create a kernel with everything built in, no >> module >> support, and when the system boots, it loads into memory and never moves >> again. >> > > Linux kernel memory is not page-able, but memory allocated through vmalloc > can still cause page fault. How device drivers using vmalloc handle this? Pages allocated via vmalloc call won't generate page-faults. > > > _______________________________________________ > Kernelnewbies mailing list > Kernelnewbies@xxxxxxxxxxxxxxxxx > http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies > -- Leon Romanovsky | Independent Linux Consultant www.leon.nu | leon@xxxxxxx _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
