[Sunhelp] SGML tools on Solaris7 or non-GNUified Solaris

[James Lockwood]

On Tue, 23 Nov 1999, Wes Hofmann wrote:

> I understand that the very-small-grain kernel locking implemented in Solaris
> is what allows it to scale so well, but also slows it down on small
> single-processor boxes.  I'd heard that Sun has or is planning to releasse
> the Solaris sources.  If this has been done, where would I find them?  Also,

They are planning to do this.  Note that not all of Solaris is Sun's
intellectual property so they will not be able to release everything.

> if this has been done, wouldn't it be possible to edit and recompile the
> kernel in a manner that it implements little or no kernel locking to speed
> it up on my little single-processor SPARCbook?  I don't now how they laid
> out the source code, but in Linux, it is very simple to tell the kernel to
> either use, or not use finer grain locking depending on if you're compiling
> for SMP or not.  Thanks for any info!

Speaking as someone who has hacked the code, it would be quite difficult.
The whole Solaris kernel is built around throughput (and RT response time
in some areas) and sacrificing this would net you a smaller gain than you
might think.  True, you might decrease syscall overhead.  But how much
syscall time is your machine really using?  If it's constantly stuck in
userland or swapping (as is likely with Netscape involved) then tweaking
the kernel will not help one bit.

Use mpstat, iostat and vmstat to help find your bottlenecks.  Once you
know exactly what they are you can start to address them.

-James