[Toybox] [PATCH] vmstat: fix units for bi and bo columns

[enh]

(from https://android-review.googlesource.com/#/c/169271/.)

Author: Colin Cross <ccross at android.com>
Date:   Tue Sep 1 15:41:34 2015 -0700

    vmstat: fix units for bi and bo columns

    pgpgin and pgpgout in /proc/vmstat are in kbytes, not pages.
    (see http://lxr.free-electrons.com/source/mm/vmstat.c?v=4.2#L1310).
    Remove the extra * page_kb for io_in and io_out.

diff --git a/toys/other/vmstat.c b/toys/other/vmstat.c
index 5b79702..870da48 100644
--- a/toys/other/vmstat.c
+++ b/toys/other/vmstat.c
@@ -2,7 +2,7 @@
  *
  * Copyright 2012 Elie De Brauwer <eliedebrauwer at gmail.com>
  *
- * TODO: I have no idea how the "io" and "system" categories are calculated.
+ * TODO: I have no idea how "system" category is calculated.
  * whatever we're doing isn't matching what other implementations are doing.

 USE_VMSTAT(NEWTOY(vmstat, ">2n", TOYFLAG_BIN))
@@ -33,8 +33,10 @@ struct vmstat_proc {
   uint64_t user, nice, sys, idle, wait, irq, sirq, intr, ctxt,
running, blocked;
   // From /proc/meminfo (units are kb)
   uint64_t memfree, buffers, cached, swapfree, swaptotal;
+  // From /proc/vmstat (units are kb)
+  uint64_t io_in, io_out;
   // From /proc/vmstat (units are pages)
-  uint64_t io_in, io_out, swap_in, swap_out;
+  uint64_t swap_in, swap_out;
 };

 // All the elements of vmstat_proc are the same size, so we can populate it as
@@ -141,7 +143,8 @@ void vmstat_main(void)
       // Adjust rate and units
       if (i>5) out -= oldptr[order[i]];
       if (order[i]<7) out = ((out*100) + (total_hz/2)) / total_hz;
-      else if (order[i]>15) out = ((out * page_kb)+(units-1))/units;
+      else if (order[i]>17) out = ((out * page_kb)+(units-1))/units;
+      else if (order[i]>15) out = ((out)+(units-1))/units;
       else if (order[i]<9) out = (out+(units-1)) / units;

       // If a field was too big to fit in its slot, try to compensate later