Re: libthr and 1:1 threading.

On Wed, 2 Apr 2003, Sheldon Hearn wrote:

> On (2003/04/02 06:05), Terry Lambert wrote:
> 
> > > I think Jeff (or someone else?) said, that some web browsers gain
> > > "something" too (serialization issues with libc_r)? I had the impression
> > > that this also applies to UP systems.
> > > 
> > > Do I misremember this? If not, does it not apply to UP systems as well?
> > 
> > FWIW: the libc_r reentrancy isn't fixed by a 1:1 model for
> > anything but calls for which there are no non-blocking
> > alternative kernel APIs.  [...long ramble...]
> 
> For all the rambling, I'm happy to report that my SCHED_ULE + libthr UP
> workstation feels noticibly more responsive when I have several Mozilla
> tabs all loading pages simultaneously while I'm trying to make a
> threaded Java IDE do something sensible. 
> 
> It's possible that I'm actually seeing the impact of other changes that
> have been committed in the last week, I suppose. 

You should notice marked interactivity and UI latency improvements with
threaded GUI apps over libc_r because GUI threads will generally no longer
be blocked when disk I/O and blocking I/O occurs.  For example,
applications like Open Office, Netscape, et al, really get a lot better
with 1:1.  Likewise, non-interactive applications that are disk
I/O-intensive, such as mysql, will also perform substantially better
because a thread that hits blocking using an interface that doesn't
support non-blocking I/O (such as the file system) won't clog up the
application.

Robert N M Watson             FreeBSD Core Team, TrustedBSD Projects
robert_at_fledge.watson.org      Network Associates Laboratories