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+A note about CPU utilization...
+
+For HP-UX 11.0 <= system < 11.23 the configure script will select the
+"pstat" CPU utilization mechanism.  This mechanism is the familiar
+HP-UX idle counter mechanism (for all incense and porpoises) and
+requires calibration.  See src/netcpu_pstat.c for all the details.
+
+For HP-UX 11.23 >= system, the configure script will select the
+"pstatnew" CPU utilization mechanism.  11.23 adds cycle counts for
+user, kernel and interrupt modes to the idle cycle counter.  As such,
+it _should_ be possible to simply take the sum of the four and the
+fractions and know how much time was spent in each mode.
+HOWEVER... there is a bug in the accounting for interrupt cycles,
+where interrupt cycles go missing.  SOOO, since there is an accurate
+way to know what the total number of cycles should have been over the
+interval, and we know (ass-u-me) that the idle cycle counter is good
+(since the pstat mechanism has tested that one OK), we will take the
+ratio of idle to total cycles to compute CPU util.  
+
+We will still calculate fractions for user, kernel and interrupt, and
+report them in debug (-d) output, but with a warning for interrupt
+time.  See src/netcpu_pstatnew.c for all the details.
+
+Up through HP-UX 11.23 (aka 11iV2) if you enable burst mode, and
+happen to send sub-MSS requests and/or responses you _cannot_ assume
+that the packet per second rate on the wire will match the transaction
+per second rate reported by netperf, even if you set TCP_NODELAY with
+the test-specific -D option.  The HP-UX 11.X TCP stack likely will be
+generating some immediate 'standalone' ACKnowledgements which may not
+be generated by other stacks.  This has been reported to the HP-UX TCP
+folks, and an announcement will be made when that issue is resolved.