svn commit: r218966 - head/sys/vm
brde at optusnet.com.au
Sun Feb 27 12:12:16 UTC 2011
On Sun, 27 Feb 2011, Bruce Cran wrote:
> On Thu, 2011-02-24 at 10:36 +1100, Bruce Evans wrote:
>> I would cast operand(s) in the expression as necessary to prevent overflow
>> of subexpressions. vm_pindex_t would work, but I prefer to use a type
>> related to the subexpressions. Not sure what that is. Maybe just
>> uintmax_t for safety (even that is not safe if the subexpressions have
>> large values). So:
>> (uintmax_t)swap_bcount * SWAP_META_PAGES * n / mumble.
> Following Alan's suggestion, I've attached an updated patch which uses a
> cast to u_long and returns long.
I thought he only meant to return long. The units being returned are
PAGE_SIZE smaller than the units in the expression. But I don't know
exacty how large swp_bcount can be. If everything fits in a single
object, then vm_size_t = u_int on 32-bit machines is enough.
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