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Re: Tracking adresses of write and read



On Wed, May 16, 2001 at 05:34:06PM +0200, Fabrice Gautier wrote:
> On Wed, 16 May 2001 15:24:05 +0200
> Erik Mouw <J.A.K.Mouw@ITS.TUDelft.NL> wrote:
> > > I would like to be abble to see which physical adress i'm
> > > writing/reading to when I write/read in the mmap-ed memory.
> > > 
> > > Who could i do this? 
> > 
> > My guess:
> > 
> >   unsigned long phys_addr;
> > 
> >   phys_addr = virt_to_phys(virtual_address);
> >   printk(KERN_INFO "%s: phys_addr = 0x%08x\n", __FUNCTION__, phys_addr);
> 
> 
> Err.. Can I do this in the user space program??? That's where i'm doing
> the reads/writes

No. The userland program shouldn't even *care* about the physical
address. As long as the kernel does the physical to virtual mapping
correct the userland program should work.

> I think both virt_to_phys and printk are kernel functions, not syscall
> or libc function.

What did you expect on a mailing list with "kernel" in its name? :)


Erik

-- 
J.A.K. (Erik) Mouw, Information and Communication Theory Group, Department
of Electrical Engineering, Faculty of Information Technology and Systems,
Delft University of Technology, PO BOX 5031,  2600 GA Delft, The Netherlands
Phone: +31-15-2783635  Fax: +31-15-2781843  Email: J.A.K.Mouw@its.tudelft.nl
WWW: http://www-ict.its.tudelft.nl/~erik/
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