Fred, There are actually two flavors of CMM: Cooperative Memory Management which is a set of APIs in Linux that controls putting pages of a Linux guest out of use. This is often described as a balloon technique where the balloon is inflated/deflated to push out unneeded memory. z/VM's VMRM (VM Resource Manager) added support for this where it monitors the overall system performance and issues calls to a list of Linux guests to control the balloons. At times this flavor of CMM has been referred to as CMM 1. More details can be found at: http://www.vm.ibm.com/sysman/vmrm/vmrmcmm.html
The other flavor is Collaborative Memory Management or CMM Assist (CMMA) or Memory Assist or CMM 2. This involves changes in z/VM 5.3, hardware, and Linux. For z/VM 5.3, I would recommend being on current service, particularly VM64297 should be on the system. You'll also want to be current on Linux service. The full support uses a new instruction. On machines where this instruction does not exist, we can simulate the instruction which does take additional processor time. The concept with CMMA is that Linux and VM exchange information on their use/state of guest pages and their backing in z/VM. This allow z/VM to be smarter about what pages are stolen, and other efficiencies. In both CMM flavors, the benefit is proportional to the potential. On systems where the guests are grossly misconfigured, or over sized, you will see the most benefit. The full performance evaluation is still being worked, and we hope to have the updated Performance report out by January 22nd. There was a smaller, early look study done by another group at IBM that is available at: http://www.ibm.com/support/techdocs/atsmastr.nsf/WebIndex/WP101151 I hope that helps. Regards, Bill Fred Schmidt <[EMAIL PROTECTED]> writes: > >Hi, > >I'm having a play with VMRM Cooperative Memory Management, now I have z/VM >5.3 and SLES 10.1 installed. However, I'm not sure that it is working >correctly. > >From z/VM, I see.... > > q memassist for user vmlxtst5 >ALL USERS SET - ON > >USER SETTING STATUS >VMLXTST5 ON ACTIVE,SIMULATED > >... with the "SIMULATED" meaning that assist is not installed, but is >being simulated by CP, according to the HELP info. I take that to mean >that Linux is not set up correctly. Or am I barking up the wrong tree >here? > > >From Linux, I have specified the following in /etc/zipl.conf and run zipl >-V .... > > parameters = "dasd=150-15F root=/dev/dasda1 cmm.sender=VMRMSVM >TERM=dumb" > >I have also issued... > >modprobe cmm sender=VMRMSVM > >... and lsmod confirms that cmm is loaded. > >cat /proc/sys/vm/cmm_pages shows values that match those recorded in >VMRMSVM's log file for the SMSG entries for the same time period, so it >seems that z/VM is telling Linux to reduce memory. > >But is Linux taking any notice? How do I confirm that it is? I don't see >any corresponding reduction in memory usage using top in Linux, or PERFKIT >in z/VM. > >Regards, >Fred Schmidt >Department of Corporate and Information Services (DCIS) >Data Centre Services (DCS) >Northern Territory Government, Australia >--=_alternative 002C115A692573AE_= >Content-Type: text/html; charset="US-ASCII" > > ><br><font size=2 face="sans-serif">Hi,</font> ><br> ><br><font size=2 face="sans-serif">I'm having a play with VMRM Cooperative >Memory Management, now I have z/VM 5.3 and SLES 10.1 installed. However, >I'm not sure that it is working correctly.</font> ><br> ><br><font size=2 face="sans-serif">From z/VM, I see....</font> ><br> ><br><font size=2 face="sans-serif"> q memassist for user vmlxtst5 > </font> ><br><font size=2 face="sans-serif">ALL USERS SET - ON > </font> ><br><font size=2 face="sans-serif"> > > </font> ><br><font size=2 face="sans-serif">USER SETTING >STATUS </font> ><br><font size=2 face="sans-serif">VMLXTST5 ON > ACTIVE,SIMULATED </font> ><br> ><br><font size=2 face="sans-serif">... with the "SIMULATED" meaning >that assist is not installed, but is being simulated by CP, according to >the HELP info. I take that to mean that Linux is not set up correctly. >Or am I barking up the wrong tree here? </font> ><br> ><br> ><br><font size=2 face="sans-serif">From Linux, I have specified the following >in /etc/zipl.conf and run zipl -V ....</font> ><br> ><br><font size=2 face="sans-serif"> parameters = >"dasd=150-15F >root=/dev/dasda1 cmm.sender=VMRMSVM TERM=dumb"</font> ><br> ><br><font size=2 face="sans-serif">I have also issued...</font> ><br> ><br><font size=2 face="sans-serif">modprobe cmm sender=VMRMSVM</font> ><br> ><br><font size=2 face="sans-serif">... and lsmod confirms that cmm is >loaded.</font> ><br> ><br><font size=2 face="sans-serif">cat /proc/sys/vm/cmm_pages shows >values that match those recorded in VMRMSVM's log file for the SMSG entries >for the same time period, so it seems that z/VM is telling Linux to reduce >memory. </font> ><br> ><br><font size=2 face="sans-serif">But is Linux taking any notice? How >do I confirm that it is? I don't see any corresponding reduction in memory >usage using top in Linux, or PERFKIT in z/VM.</font> ><br><font size=2 face="sans-serif"><br> >Regards,<br> >Fred Schmidt<br> >Department of Corporate and Information Services (DCIS)<br> >Data Centre Services (DCS)<br> >Northern Territory Government, Australia</font> >--=_alternative 002C115A692573AE_=--
