>>> Obviously you can have "fast clear" for objects with lengths that >>> 256-multiple using n*XC - however I have often wished for a >>> ZERO=YES option on the CPOOL BUILD so that you are guaranteed a >>> clean cell for each subsequent CPOOL GET. If anyone else agrees, I >>> might consider raising a Share requirement .... >> >> Such a requirement would likely be rejected. There isn't anything >>CPOOL can do to obtain better performance for clearing a cell than >>what you can do in your own code. Clearing done by CPOOL would be >>guaranteed to be at least marginally slower, and in some cases >>considerably slower, than clearing done by your code.
>If the CPOOL spanned one or more 4K aligned pages, then a ZERO=YES >could zero the area before and after the 4K block and just set the >virtual page table entries for the block to be a read-only dedicated >pre-zero'ed page. I seem to have the impression that STORAGE does >this for allocated pages in some cases (I think that allocated area >has to be page aligned and a multiple of page length to get >pre-zeroed storage). There are no cases where STORAGE provides you with a read-only page. What you are suggesting would be considerably slower than clearing done by your own code. Jim Mulder z/OS System Test IBM Corp. Poughkeepsie, NY ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
