Subject: Re: loaning for read() of regular files
To: Stephan Uphoff <ups@tree.com>
From: Chuck Silvers <chuq@chuq.com>
List: tech-kern
Date: 02/16/2005 18:16:41
On Wed, Feb 16, 2005 at 01:54:18PM -0500, Stephan Uphoff wrote:
> On Tue, 2005-02-15 at 22:23, Chuck Silvers wrote:
> > On Tue, Feb 15, 2005 at 05:00:09PM -0500, Stephan Uphoff wrote:
> > > Mhhh .. for SMP it could be beneficial just to call pmap_remove for the
> > > whole range before the pmap_enter calls to cut down on the number of IPI
> > > calls. (At least for multi page reads on i386)
> > 
> > hmm, on the second thought, the IPI coalescing should be taken care of
> > by deferring them until pmap_update() (which I was also missing).
> > the i386 pmap doesn't take advantage of this currently, though.
> 
> Yes, fixing the i386 pmap to take advantage of  pmap_update() is
> probably a better idea.
> 
> I am planning another attack on Manuel Bouyer's "TLB IPI rendezvous
> failed..." problem sometime in the next couple of weeks and might as
> well take a look at  pmap_update() while I am in the neighborhood.

excellent, thanks.

-Chuck