> If the next use turns out to be for a page-in from aux or from a DIV object, then there is no need to zero it.
Very true. And it make sense when zeroing a page was expensive to the processing power available to a CEC. I wonder though, if a separate process - an off board process, like the process that adjusts page last reference used byte, could recognize that the page needed to be zeroed? I'm just brainstroming. >Also, the residual data in available frames is sometimes useful when doing problem diagnosis using a stand-alone dump. For my experience, I've see more dumps from non-zeroed storage than from the gain of looking at freed pages in a stand-alone dump (which I've never done). As a side, I really appreciate the BEAR. I has helped with a lot with random storage values. Tx Chip Grantham | Ameritas | Sr. IT Consultant | cgrant...@ameritas.com 5900 O Street, Lincoln NE 68510 | p: 402-467-7382 | c: 402-429-3579 | f: 402-325-4030 Jim Mulder <d10j...@us.ibm.com> Sent by: IBM Mainframe Discussion List <IBM-MAIN@bama.ua.edu> 06/03/2011 09:34 AM Please respond to IBM Mainframe Discussion List <IBM-MAIN@bama.ua.edu> To IBM-MAIN@bama.ua.edu cc Subject Re: What is the current feeling for MVC loop vs. MVCL? > I've never understood why a page is put on the available frame queue > without first zeroing it. It's kinda like putting dirty dishs in the > cupboard and washing them when you take them out only if company > complains. It would seem to me, in my humble opinion, easy enough to put > an engine on the chip with the sole responsibility of zeroing the page and > putting it on the queue. My humble opinion. At the time a frame is made available, it is not known whether its next use will require it to be zeroed or not. If the next use turns out to be for a page-in from aux or from a DIV object, then there is no need to zero it. Also, the residual data in available frames is sometimes useful when doing problem diagnosis using a stand-alone dump. Jim Mulder z/OS System Test IBM Corp. Poughkeepsie, NY ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html ******* This message may contain confidential information intended only for the use of the addressee(s) named above and may contain information that is legally privileged. If you are not the addressee, or the person responsible for delivering it to the addressee, you are hereby notified that reading, disseminating, distributing or copying this message is strictly prohibited. If you have received this message by mistake, please immediately notify us by replying to the message and delete the original message immediately thereafter. Thank you. ******* ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
