[Bug other/10944] alloc_page in ggc-page.c is slow

["steven at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=10944



------- Additional Comments From steven at gcc dot gnu dot org  2003-10-12 20:34 -------
Discussed this with Zack, and the patch "is essentially what [he] had in mind."

Zack suggested there are still a few things that need to be done, however:
1) two-level free page caching:
   - after one collection, put all freepages on the per-order lists;
   - after the next collection, put all thepages that are still on
     the per-order lists on the global list;
   - and after a third collection release the pages still on the global
     list tothe OS.
   This probably takes some fiddling with the page_entry struct.  Also
   we'll have to see how this works in relation with page groups

2) scavenge pages from other per-order lists rather than go back to the
   OS for more.
   (Personally I think this won't be necessary if (1) is implemented properly)