22 Jun, 2005

1 commit

  • Remember that ironic get_user_pages race? when the raised page_count on a
    page swapped out led do_wp_page to decide that it had to copy on write, so
    substituted a different page into userspace. 2.6.7 onwards have Andrea's
    solution, where try_to_unmap_one backs out if it finds page_count raised.

    Which works, but is unsatisfying (rmap.c has no other page_count heuristics),
    and was found a few months ago to hang an intensive page migration test. A
    year ago I was hesitant to engage page_mapcount, now it seems the right fix.

    So remove the page_count hack from try_to_unmap_one; and use activate_page in
    unuse_mm when dropping lock, to replace its secondary effect of helping
    swapoff to make progress in that case.

    Simplify can_share_swap_page (now called only on anonymous pages) to check
    page_mapcount + page_swapcount == 1: still needs the page lock to stabilize
    their (pessimistic) sum, but does not need swapper_space.tree_lock for that.

    In do_swap_page, move swap_free and unlock_page below page_add_anon_rmap, to
    keep sum on the high side, and correct when can_share_swap_page called.

    Signed-off-by: Hugh Dickins
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Hugh Dickins
     

17 May, 2005

1 commit


17 Apr, 2005

1 commit

  • Initial git repository build. I'm not bothering with the full history,
    even though we have it. We can create a separate "historical" git
    archive of that later if we want to, and in the meantime it's about
    3.2GB when imported into git - space that would just make the early
    git days unnecessarily complicated, when we don't have a lot of good
    infrastructure for it.

    Let it rip!

    Linus Torvalds