lkml.org 
[lkml]   [2004]   [Mar]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patches in this message
    /
    Date
    From
    SubjectRe: [RFC][PATCH 1/3] radix priority search tree - objrmap complexity fix
    On Mon, Mar 29, 2004 at 12:50:20PM -0500, Rajesh Venkatasubramanian wrote:
    >
    >
    > > #define VN_MAPPED(vp) \
    > > - (!list_empty(&(LINVFS_GET_IP(vp)->i_mapping->i_mmap)) || \
    > > - (!list_empty(&(LINVFS_GET_IP(vp)->i_mapping->i_mmap_shared))))
    > > + (!prio_tree_empty(&(LINVFS_GET_IP(vp)->i_mapping->i_mmap)) || \
    > > + (!prio_tree_empty(&(LINVFS_GET_IP(vp)->i_mapping->i_mmap_shared))))
    >
    > I think we will need the following too:
    > (!list_empty(&(LINVFS_GET_IP(vp)->i_mmaping->i_mmap_nonlinear)
    >
    >
    > > down(&mapping->i_shared_sem);
    > > - list_for_each_entry(vma, &mapping->i_mmap_shared, shared) {
    > > + vma = __vma_prio_tree_first(&mapping->i_mmap_shared, &iter, 0, ULONG_MAX);
    > > + while (vma) {
    > > if (!(vma->vm_flags & VM_DENYWRITE)) {
    > > prohibited |= (1 << DM_EVENT_WRITE);
    > > break;
    > > }
    > > +
    > > + vma = __vma_prio_tree_next(vma, &mapping->i_mmap_shared, &iter, 0, ULONG_MAX);
    > > }
    >
    > This part looks fine. But, I am not sure whether you have to handle
    > nonlinear maps here.
    >
    > list_for_each_entry(vma, &mapping->i_mmap_nonlinear, shared) {
    > ...
    > }
    >

    I agree we should handle the nonlinear maps. since nobody uses nonlinear
    this isn't a big issue for the short term.

    There's now also a screwup in the writeback -mm changes for swapsuspend,
    it bugs out in radix tree tag, I believe it's because it doesn't
    insert the page in the radix tree before doing writeback I/O on it. This
    is my first attempt to cure it.

    --- sles/mm/page_io.c.~1~ 2004-03-29 19:05:50.014588464 +0200
    +++ sles/mm/page_io.c 2004-03-29 19:46:14.282043792 +0200
    @@ -151,8 +151,15 @@ int rw_swap_page_sync(int rw, swp_entry_
    lock_page(page);

    BUG_ON(page_mapping(page));
    + BUG_ON(PageSwapCache(page));
    SetPageSwapCache(page);
    page->private = entry.val;
    + ret = radix_tree_insert(&page_mapping(page)->page_tree, page->private, page);
    + if (unlikely(ret)) {
    + ClearPageSwapCache(page);
    + unlock_page(page);
    + return ret;
    + }

    if (rw == READ) {
    ret = swap_readpage(NULL, page);
    @@ -161,7 +168,10 @@ int rw_swap_page_sync(int rw, swp_entry_
    ret = swap_writepage(page, &swap_wbc);
    wait_on_page_writeback(page);
    }
    +
    + radix_tree_delete(&page_mapping(page)->page_tree, page->private);
    ClearPageSwapCache(page);
    +
    if (ret == 0 && (!PageUptodate(page) || PageError(page)))
    ret = -EIO;
    return ret;
    then there's x86-64 bombing too:

    --- sles/arch/x86_64/ia32/ia32_binfmt.c.~1~ 2004-03-29 19:05:50.516512160 +0200
    +++ sles/arch/x86_64/ia32/ia32_binfmt.c 2004-03-29 19:53:20.031320064 +0200
    @@ -366,7 +366,7 @@ int setup_arg_pages(struct linux_binprm
    mpnt->vm_pgoff = mpnt->vm_start >> PAGE_SHIFT;
    mpnt->vm_file = NULL;
    mpol_set_vma_default(mpnt);
    - INIT_LIST_HEAD(&mpnt->shared);
    + INIT_VMA_SHARED(mpnt);
    /* insert_vm_struct takes care of anon_vma_node */
    mpnt->anon_vma = NULL;
    mpnt->vm_private_data = (void *) 0;
    the writeback part will require testing, so I'll postpone further
    updates until I get confirmation that swapsuspend works again (this is
    all low prio stuff anyways, the previous xfs list_empty miscompilation
    was scary instead so I update it quickly, since people actually uses
    MAP_SHARED/MAP_PRIVATE).
    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2005-03-22 14:02    [W:0.038 / U:0.404 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site