#Page Faults — Micron
04-Oct-95 12:03:37
Sb: #193768-#Page Faults — Micron
Fm: David Rhoten 71450,2654
To: Judy Weller 72662,536
Judy:
A "page fault" is NOT a "problem", software or hardware. A page fault is when
the virtual memory manager (in this case, Phar Lap's) tries to access a virtual
memory page that is not currently in memory (ie, it has been paged to disk).
When the page fault exception occurs, the VMM brings the page into memory and
restarts the instruction that caused the page fault — thus the application
software never knows the data wasn't there all along.
Now, of course, there can be an error that occurs DURING a page fault, and I
would agree that running 32-bit DOS extender software such as PharLap with QEMM
stealth-mode enabled is kind of asking for trouble, but I have NEVER had a
problem with AutoCAD, AniPro or 3DS that was caused by QEMM. (FWIW, the "dump"
that QEMM often gives with an exception error is a "feature" of QEMM — it's
reporting a condition that DOS doesn't — so whereas DOS would've just locked
up or dumped you out of the program, QEMM gives you some help in trying to
discover the cause.)
Dave