Thanks Mulyadi and Prabhu for your enlightening description.<div><br></div><div>What a plight!!! memory has become soo cheap nowadays that I don't have less than 1GB system and difficult to find someone in my knowledge having less than 1 GB memory.</div>
<div><br></div><div>Although does this means that pages in FCOM will never have page fault? and if this is true is this the reason why we assign NULL to memory descriptor ( mm_struct ) for kernel threads?</div><div><br></div>
<div><br></div><div><div><div>Regards,</div><div>Piyush</div><div><div><br><div class="gmail_quote">On Tue, Jun 28, 2011 at 8:56 PM, Mulyadi Santosa <span dir="ltr"><<a href="mailto:mulyadi.santosa@gmail.com">mulyadi.santosa@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">Hi :)<br>
<div class="im"><br>
On Tue, Jun 28, 2011 at 17:49, Prabhu nath <<a href="mailto:gprabhunath@gmail.com">gprabhunath@gmail.com</a>> wrote:<br>
> Dear Mulyadi,<br>
><br>
> You are always an important character to jump in to any discussion and it<br>
> will be our great pleasure.<br>
<br>
</div>Thanks :) Well, sometimes I just feel hesitate to break into someone's<br>
else discussion.<br>
<div class="im"><br>
> Please see inline for my views.<br>
><br>
> On Tue, Jun 28, 2011 at 3:46 PM, Mulyadi Santosa <<a href="mailto:mulyadi.santosa@gmail.com">mulyadi.santosa@gmail.com</a>><br>
> wrote:<br>
</div><div class="im">> In a 3G/1G partition. 1G of Kernel virtual address space is divided into<br>
> 896MB and 128 MB regions. I name them as<br>
> Fixed Constant Offset mapped region (FCOM) - 0xC0000000 to 0xF8000000<br>
> Dynamically Arbitrarily Mappable region (DAMR) - 0xF8000000 to 0xFFFFFFFF<br>
<br>
</div>Great naming! You beat me on that aspect :)<br>
<br>
PS: Once there was a patch to create 4:4 VM split written by Ingo<br>
Molnar. It does maximize address space at the expense of full TLB<br>
flush on every context switch. AFAIK it once included in Fedora core 2<br>
or 3, but dropped afterward since it puts more negative impacts rather<br>
than positive enhancement (in virtual memory management point of view)<br>
<font color="#888888"><br>
--<br>
</font><div><div></div><div class="h5">regards,<br>
<br>
Mulyadi Santosa<br>
Freelance Linux trainer and consultant<br>
<br>
blog: <a href="http://the-hydra.blogspot.com" target="_blank">the-hydra.blogspot.com</a><br>
training: <a href="http://mulyaditraining.blogspot.com" target="_blank">mulyaditraining.blogspot.com</a><br>
</div></div></blockquote></div><br></div></div></div></div>