Messages in this thread | | | Date | Mon, 29 Mar 2004 19:12:34 +0100 (BST) | From | Hugh Dickins <> | Subject | Re: [RFC][PATCH 1/3] radix priority search tree - objrmap complexity fix |
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On Mon, 29 Mar 2004, Andrea Arcangeli wrote: > > Here a further update for xfs: > > --- sles/fs/xfs/linux/xfs_vnode.h.~1~ 2004-03-29 18:33:20.047028592 +0200 > +++ sles/fs/xfs/linux/xfs_vnode.h 2004-03-29 19:02:37.101915648 +0200 > @@ -601,8 +601,8 @@ static __inline__ void vn_flagclr(struct > * Some useful predicates. > */ > #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)))) > #define VN_CACHED(vp) (LINVFS_GET_IP(vp)->i_mapping->nrpages) > #define VN_DIRTY(vp) mapping_tagged(LINVFS_GET_IP(vp)->i_mapping, \ > PAGECACHE_TAG_DIRTY)
Needs also to check !list_empty(&(LINVFS_GET_IP(vp)->i_mapping->i_mmap_nonlinear))
Various arches need a similar conversion too (and use page_mapping(page) rather than page->mapping: see arch and include/asm in my anobjrmap 3/6).
Those arches which do more than test list_empty (now prio_tree_empty), arm and parisc (I think that's all): look as if they can take full advantage of the prio tree; and I hope we can ignore the nonlinears in those cases - if a page is mapped in a nonlinear vma it may suffer from D-cache aliasing inconsistencies if also mapped elsewhere in that user address space, never mind. Is that reasonable?
> and really some other bigger tree needs this part too (not a mainline > issue). > > --- sles/fs/xfs/dmapi/dmapi_xfs.c.~1~ 2004-03-29 18:33:03.781501328 +0200 > +++ sles/fs/xfs/dmapi/dmapi_xfs.c 2004-03-29 18:58:57.754261560 +0200 > @@ -228,17 +228,21 @@ prohibited_mr_events( > struct address_space *mapping = LINVFS_GET_IP(vp)->i_mapping; > int prohibited = (1 << DM_EVENT_READ); > struct vm_area_struct *vma; > + struct prio_tree_iter iter; > > if (!VN_MAPPED(vp)) > return 0; > > #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0) > 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); > } > up(&mapping->i_shared_sem); > #else
This looks horrid (not your change, the original), and would need to look at nonlinears too; but I thought this was what i_writecount < 0 is for?
Hugh
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