At 12:32 -0400 on 06/01/2011, Jim Mulder wrote about Re: What is the
current feeling for MVC loop vs. MVCL?:
> 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).
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