Subject: Re: pmap.c hacking...
To: Frank van der Linden <>
From: Jason Thorpe <>
List: port-amd64
Date: 03/29/2007 11:39:30
On Mar 29, 2007, at 4:42 AM, Frank van der Linden wrote:

> Andrew Doran wrote:
>> As an aside the amd64 pmap is lacking the lazy switching that the  
>> i386 pmap
>> does, which eliminates reloads of %cr3 / TLB flushes when  
>> switching to
>> kthreads, or when switching between threads within the same  
>> process. Also
>> IIRC the xen pmap is an old, slightly modified version of the i386  
>> pmap and
>> should be merged back in with an #ifdef XEN.
>> The amd64 pmap was written to work on i386 too. Can anyone comment  
>> on what
>> the original issues were that prevented sharing it? Frank?
> yamt resolved any remaining issues and came up with a shared pmap.  
> I agree that it should be shared, however, others disagreed, and  
> the shared pmap was not committed.

The others be damned!  It should be shared, period!

> I don't remember what the arguments were. I still think that a  
> shared pmap should be committed.
> - Frank

-- thorpej