From: Paul Khuong <pvk@pvk.ca>
Date: Sun, 3 Jul 2011 16:45:42 +0000 (-0400)
Subject: Split GENCGC_PAGE_BYTES in 3 constants
X-Git-Url: http://repo.macrolet.net/gitweb/?a=commitdiff_plain;h=5c0a884190d6c98448d86fb05e1e99df901c9bf8;hp=5c0a884190d6c98448d86fb05e1e99df901c9bf8;p=sbcl.git

Split GENCGC_PAGE_BYTES in 3 constants

 * We still have BACKEND_PAGE_BYTES, which should be a conservative
   over-approximation of the OS's page size.

 * GENCGC_PAGE_BYTES is mostly replaced by GENCGC_CARD_BYTES, the
   byte granularity at which we track writes to old generations.
   While we're using mprotect-based write barriers, this should be
   a multiple of BACKEND_PAGE_BYTES.

 * GENCGC_ALLOC_GRANULARITY is the minimum size we attempt to make
   each allocation region.  Should be a multiple of GENCGC_CARD_BYTES.
   While we have largeish cards, this shouldn't ever be an issue, but
   it might if we ever go down to < 1k cards.

 * GENCGC_RELEASE_GRANULARITY is the minimum size at which we release
   address space to the OS.  This should always be a multiple of
   BACKEND_PAGE_BYTES.

 * For now, all three new constants are equal to BACKEND_PAGE_BYTES.
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