Re: CVS commit: [matt-nb5-mips64] src/sys/arch/mips

[Matt Thomas <matt%3am-software.com@localhost>]

On Feb 24, 2010, at 10:31 PM, David Laight wrote:

> On Thu, Feb 25, 2010 at 05:53:23AM +0000, Matt Thomas wrote:
>> 
>> Log Message:
>> Make the UP and MP ASID allocation algorithm common.  Significantly improve
>> the algorithm.  Now when we exhaust the ASIDs, interrogate the TLB for active
>> ASIDS and release all the other for future allocations.  This leaves the
>> TLB entries with ASIDs valid avoiding the need to re-incur TLB misses for
>> them.
> 
> I presume it is willing to kill some TLB entries if the above doesn't
> find any (or enough) free ASIDs ?
> Or is the ASID number space guaranteed to be significantly higher that
> the number of TLBs ??

If it can't reclaim at least half of the ASID space, it invalidates all ASID 
based 
entries in the TLB.  And for MIPS32/MIPS64 the ASID space is at least 4x the 
number 
of TLB entries.