<p dir="ltr"><br>
On 10-Sep-2014 6:24 pm, <<a href="mailto:Valdis.Kletnieks@vt.edu">Valdis.Kletnieks@vt.edu</a>> wrote:<br>
><br>
> On Wed, 10 Sep 2014 14:45:23 +0530, Manavendra Nath Manav said:<br>
><br>
> > But if the total RAM is limited (less than 896MB LOWMEM), for example as in<br>
> > embedded devices how the kernel code be kept in RAM all the time. Am I<br>
> > correct to assume that the kernel pre-fetches all pages when entering<br>
> > kernel mode from user mode?<br>
><br>
> No, kernel code is loaded by your boot loader, and *it stays there*. Similarly,<br>
> if you modprobe something, the kernel allocates the page, loads the code,<br>
> and leaves it there.<br>
><br>
> Particularly in embedded devices, where you know all the modules the kernel may<br>
> need, it's common to just create a kernel with everything built in, no module<br>
> support, and when the system boots, it loads into memory and never moves again.<br>
></p>
<p dir="ltr">Linux kernel memory is not page-able, but memory allocated through vmalloc can still cause page fault. How device drivers using vmalloc handle this?<br>
</p>