TOP program on OSx4.1

[Jeff Forys]

	From:    geops!steve at june.cs.washington.edu  (Steve Malone)
	Subject:  TOP program on OSx4.1

	The `top' program does not seem to work under OSx4.1.
	It did just fine under 3.5 [...] (The problem seem to
	be in the code or structures involving the CPUSTATE).
---
Not exactly.  Pyramids' OSx4.0 release was apparently geared for
multiple processors (where older machines have a multiple of 1).
As a result, they moved `cp_time' [*] into a per-processor struct
(cleverly called `percpu') and changed it's name to `cpu_time'.
The trick then, is finding this thing.

Since we only have single-processor 90x machines here (with no
plans to upgrade), my patch simply grabs the `percpu' struct for
the first (i.e. only) processor.  If you have multiple-CPUs, this
patch will "work", but generate bogus data.  I suppose that, in
the case of multiple-processors, for each state, one might divide
the time spent by each processor by the total number of processors.

Context diff's for `top.c' follow.  After applying them, compile
with `-DPYR4_0' (hmm, should have been PYR=41... too late :-)).

Good luck,
Jeff Forys

[*] The `cp_time' (or Pyramids' `percpu.cpu_time') array keeps track
of how much time a processor spends in each of `CPUSTATES' states.
Usually there are 4 states; user, nice, system, and idle.
-------------------------------- cut here -----------------------------
*** /tmp/,RCSt1017858	Tue Sep 20 02:24:28 1988
--- top.c	Wed Aug 26 20:30:46 1987
***************
*** 38,43 ****
--- 38,46 ----
  #include <sys/proc.h>
  #include <sys/dk.h>
  #include <sys/vm.h>
+ #ifdef PYR4_0
+ #include <sys/systm.h>
+ #endif
  
  /* includes specific to top */
  #include "layout.h"
***************
*** 63,69 ****
--- 66,76 ----
  #define X_AVENRUN	0
      { "_ccpu" },
  #define X_CCPU		1
+ #ifdef PYR4_0
+     { "_percpu" },
+ #else
      { "_cp_time" },
+ #endif
  #define X_CP_TIME	2
      { "_hz" },
  #define X_HZ		3
***************
*** 101,106 ****
--- 108,117 ----
  
  /* All this is to calculate the cpu state percentages */
  
+ #ifdef PYR4_0
+ struct percpu cpus[NCPU];	/* pyramids expect multiple CPUs */
+ #endif
+ 
  long cp_time[CPUSTATES];
  long cp_old[CPUSTATES];
  long cp_change[CPUSTATES];
***************
*** 473,479 ****
--- 484,505 ----
  	getkval(proc, pbase, bytes, "proc array");
  
  	/* get the cp_time array */
+ 
+ #ifdef PYR4_0
+ 	/*
+ 	 * OSx4.0 uses a struct for each CPU.  We have only one,
+ 	 * so the easy thing to do is just use it.  (JEF)
+ 	 */
+ 	{
+ 	    register int i;
+ 
+ 	    getkval(cp_time_offset, cpus, sizeof(cpus), "_percpu");
+ 	    for (i=0; i<CPUSTATES; i++)
+ 		cp_time[i] = cpus[0].cpu_time[i];
+ 	}
+ #else
  	getkval(cp_time_offset, cp_time, sizeof(cp_time), "_cp_time");
+ #endif
  
  	/* get load average array */
  	getkval(avenrun_offset, avenrun, sizeof(avenrun), "_avenrun");