On Thu, 2 Jun 2011 17:25:50 -0400, Robert A. Rosenberg wrote:
>
>I might have phrased my description incorrectly. What I was saying is
>that when you initially allocate an virtual area when that area is
>actually mapped to memory the page that gets loaded (paged-in) is
>pre-zeroed. I was just suggesting that this would be simplest to do
>if there was a single pre-zeroed page to be used for the page-in and
>the mapping table entry was marked to not use that DASD copy as the
>target when the virtual page needs to be paged out again.
>
Are you suggesting that it's more efficient to zero a page
by reading in a page of zeroes from DASD than by MVC[L],
overlapping, in a loop, whatever?

Based on the anecdotes here so far, I'd vote for STM
in a loop.

>BTW: Is my impression that if I use STORAGE to allocate a
>MULTIPLE-PAGE area, then the virtual page will be pre-zeroed? If so,
>how is this done?
>
Does it depend on whether the physical page(s) allocated
previously belonged to a different address space or to the
same address space?

-- gil

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