questions about superpages

Scott Bennett bennett at cs.niu.edu
Wed Dec 30 05:30:00 UTC 2009


     A short while ago, I wrote:
>     I poked around in the stuff in /sys/i386/vm looking for the threshholds

     That should have said, "/sys/vm", not what I wrote.  Sorry for any
confusion.

>of process memory size for promotion to 4 MB pages and for demotion back to
>4 KB pages, but didn't see them.  Can someone tell me what those threshholds
>are?  I'm assuming there must be a larger threshhold for promotion than for
>demotion on the basis that hysteresis is necessary to keep the VM system
>continual oscillation of processes with memory requirements close to the
>promotion thresshold.  If someone who knows can also point me toward the
>place that these values appear in the source code, I'd appreciate that, too.
>     Thanks in advance!


                                  Scott Bennett, Comm. ASMELG, CFIAG
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