The problem is the amount of virtual address space available to M5.  
On a 32bit system that is only about 3GB. Since the simulated memory  
is mapped as a contiguous block you need 2GB of contiguous free  
address space.

When starting from a checkpoint the memory in the config file is  
mmaped, and then when the checkpoint in unserialized, that memory is  
unmmaped, the gziped memory image is uncompressed and loaded. The  
problem is probably that the munmap() is before the gzdopen() so  
gzdopen is probably getting a small chunk of the 2GB space which  
means that you can't mmap it again. Moving the munmap() to after the  
gzdopen() will probably fix the problem for you.

The other two solutions for being able to have a bigger amount of  
memory are:
1. Use a 64bit system.
2. Change physical memory to allocate pages instead of the entire  
memory at once and read/write them to disk as they are needed (kind  
of like implementing  VM in M5 for the guest OS).

Ali

On Jul 26, 2006, at 11:32 PM, Adam Kaplan wrote:

> I noted that on my system I am able to start the full-system  
> simulator and
> boot Linux successfully with 2047MB of simulated DRAM (not with 2048
> though...Linux will not load), and yet when I checkpoint and try to  
> start
> simulation from checkpoint (also with 2047MB of DRAM), I get the
> following:
>
> fatal: Could not mmap physical memory!
>  @ cycle 607401203386
> [unserialize:m5/mem/functional/physical.cc, line 335]
>
> Anyone know a way around this? (It seems that the problem lies in
> the amount of mem-alloc attempted on my system.  Is the allocation
> requirement different if starting from a checkpoint?)
>
> Thanks for any help/suggestions you can provide!
>
>                                       -Adam
>
> ---------------------------------------------------------------------- 
> ---
> Take Surveys. Earn Cash. Influence the Future of IT
> Join SourceForge.net's Techsay panel and you'll get the chance to  
> share your
> opinions on IT & business topics through brief surveys -- and earn  
> cash
> http://www.techsay.com/default.php? 
> page=join.php&p=sourceforge&CID=DEVDEV
> _______________________________________________
> m5sim-users mailing list
> [email protected]
> https://lists.sourceforge.net/lists/listinfo/m5sim-users
>


-------------------------------------------------------------------------
Take Surveys. Earn Cash. Influence the Future of IT
Join SourceForge.net's Techsay panel and you'll get the chance to share your
opinions on IT & business topics through brief surveys -- and earn cash
http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV
_______________________________________________
m5sim-users mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/m5sim-users

Reply via email to