On Wed, 12 Dec 2007 09:58:04 +0930, Fred Schmidt <[EMAIL PROTECTED]> wrote:
>However, I would like to persist with CMM. My original question still >stands... how can I verify that it is actually working? Well, there are 2 answers to this. First, the Linux guest has issued at least one ESSA instruction as evidenced by Q MEMASSIST reporting "ACTIVE". The sole purpose of ESSA is to implement CMMA. Since the virtual machine didn't get an operation exception on the ESSA, it was either handled by the hardware assist or simulated by CP. Personally, I'm reasonably sure that either did what it was supposed to do with the ESSA, but Your Milage May Vary. I don't know if there are any stats in CP or Linux on pages freed via CMMA. Second, you could compare performance stats with it turned off and turned on. With it on you would expect CP to do less paging and Linux to use more CPU. See the IBM white paper "z/VM Large Memory Linux on System z" for more detailed info: http://www-03.ibm.com/support/techdocs/atsmastr.nsf/WebIndex/WP101151 Brian Nielsen
