emstat Command

Purpose

Shows emulation exception statistics.

Syntax

emstat [ -a | -v ] [ Interval ] [ Count ]

Description

The emstat command displays emulation exception statistics. Emulation exceptions can occur when some legacy applications or libraries, which contain instructions that have been deleted from older processor architectures, are executed on newer processors. These instructions may cause illegal instruction program exceptions. The operating system catches these exceptions and emulates the older instruction(s) to maintain program functionality, potentially at the expense of program performance.

The emulation exception count since the last time the machine was rebooted and the count in the current interval are displayed. The user can optionally display alignment exception statistics or individual processor emulation statistics.

The default output displays statistics every second. The sampling interval and number of iterations can also be specified.

Parameters

Item Description
Interval Interval between samples.
Count Number of iterations.

Flags

Item Description
-a Displays alignment exception statistics. This flag cannot be used with the -v flag.
-v Display individual processor statistics. This flag cannot be used with the -a flag.

Examples

  1. To display the emulation statistics every second, type: 
    emstat

    This produces the following output:

      Emulation  Emulation
  SinceBoot      Delta
    8845591          0
    8845591          0
    8845591          0
    8845591          0
    8845591          0
    8845591          0
  ...
  2. To display emulation and alignment exception statistics every two seconds, a total of 5 times, type: 
    emstat -a 2 5

    This produces the following output:

      Alignment  Alignment  Emulation  Emulation
  SinceBoot      Delta  SinceBoot      Delta
   21260604          0   70091846          0
   23423104    2162500   72193861    2102015
   25609796    2186692   74292759    2098898
   27772897    2163101   76392234    2099475
   29958509    2185612   78490284    2098050
  3. To display emulation statistics, every 5 seconds, for each processor, type: 
    emstat -v 5

    This produces the following output:

      Emulation  Emulation  Emulation  Emulation
  SinceBoot      Delta    Delta00    Delta01
   88406295          0          0          0
   93697825    5291530          0    5291530
   98930330    5232505    5232505          0
  102595591    3665261     232697    3432564
  102595591          0          0          0