[2141] in SIPB-AFS-requests
Re: afsd priorities?
daemon@ATHENA.MIT.EDU (Derek Atkins)
Sat Sep 16 18:33:31 1995
To: John Hawkinson <jhawk@MIT.EDU>
Cc: sipb-afsreq@MIT.EDU, probe@MIT.EDU
In-Reply-To: Your message of "Sat, 16 Sep 1995 03:44:14 EDT."
<199509160744.DAA26311@lola-granola.MIT.EDU>
Date: Sat, 16 Sep 1995 18:32:00 EDT
From: Derek Atkins <warlord@MIT.EDU>
AFSD works by calling a syscall that basically never returns.
However, that section of kernel code is usually sleeping, and will
only run when the afsd is "running". By making afsd higher priority,
you will cause the kernel to attempt to spend more time attempting to
run the afs syscall code.
I say attempt because it really depends on how kernel threading works.
Will one process preempt another under SunOS? I know under Linux they
will not. So when the AFS code is running, it will run to completion.
However when the AFS code comes to a place where it would normally
block, it might take a shorter time for afsd to be re-schduled to run
if it has a higher priority.
This rambling probably isn't helping. In fact, I'm still not sure if
the higher priority has any real effect. My gut feeling is that it
should have some effect, since the kernel code is only being executed
when the afsd process is "scheduled" to run. So the more it is
scheduled, the more time the kernel code has to run, and the faster it
can respond to requests.
Richard, what do you think?
-derek
