Hello Michel Lets first see snippet in another work. https://lkml.org/lkml/2012/9/4/75 [PATCH 5/7] mm rmap: remove vma_address check for address inside vma On Tue, Sep 4, 2012 at 5:20 PM, Michel Lespinasse <walken@xxxxxxxxxx> wrote: > diff --git a/mm/rmap.c b/mm/rmap.c > index 9c61bf387fd1..28777412de62 100644 > --- a/mm/rmap.c > +++ b/mm/rmap.c > @@ -510,22 +510,26 @@ void page_unlock_anon_vma(struct anon_vma *anon_vma) > > /* > * At what user virtual address is page expected in @vma? > - * Returns virtual address or -EFAULT if page's index/offset is not > - * within the range mapped the @vma. > */ > -inline unsigned long > -vma_address(struct page *page, struct vm_area_struct *vma) > +static inline unsigned long > +__vma_address(struct page *page, struct vm_area_struct *vma) > { > pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT); > - unsigned long address; > > if (unlikely(is_vm_hugetlb_page(vma))) > pgoff = page->index << huge_page_order(page_hstate(page)); The pgoff computation for huge page remains as it was. > - address = vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT); > - if (unlikely(address < vma->vm_start || address >= vma->vm_end)) { > - /* page should be within @vma mapping range */ > - return -EFAULT; > - } > + > + return vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT); > +} > + > +inline unsigned long > +vma_address(struct page *page, struct vm_area_struct *vma) > +{ > + unsigned long address = __vma_address(page, vma); > + > + /* page should be within @vma mapping range */ > + VM_BUG_ON(address < vma->vm_start || address >= vma->vm_end); > + > return address; > } > Then lets see this work. On Sat, Sep 8, 2012 at 7:26 AM, Michel Lespinasse <walken@xxxxxxxxxx> wrote: > -----------------------------8<------------------------------------- > From: Michel Lespinasse <walken@xxxxxxxxxx> > Subject: mm: replace vma prio_tree with an interval tree > > Implement an interval tree as a replacement for the VMA prio_tree. > The algorithms are similar to lib/interval_tree.c; however that code > can't be directly reused as the interval endpoints are not explicitly > stored in the VMA. So instead, the common algorithm is moved into > a template and the details (node type, how to get interval endpoints > from the node, etc) are filled in using the C preprocessor. > > Once the interval tree functions are available, using them as a replacement > to the VMA prio tree is a relatively simple, mechanical job. > > Signed-off-by: Michel Lespinasse <walken@xxxxxxxxxx> > Cc: Rik van Riel <riel@xxxxxxxxxx> > Cc: Hillf Danton <dhillf@xxxxxxxxx> > Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> > Cc: Catalin Marinas <catalin.marinas@xxxxxxx> > Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx> > Cc: David Woodhouse <dwmw2@xxxxxxxxxxxxx> > Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > --- [...] > --- /dev/null > +++ b/mm/interval_tree.c > @@ -0,0 +1,59 @@ > +/* > + * mm/interval_tree.c - interval tree for mapping->i_mmap > + * > + * Copyright (C) 2012, Michel Lespinasse <walken@xxxxxxxxxx> > + * > + * This file is released under the GPL v2. > + */ > + > +#include <linux/mm.h> > +#include <linux/fs.h> > +#include <linux/interval_tree_generic.h> > + > +static inline unsigned long vma_start_pgoff(struct vm_area_struct *v) > +{ > + return v->vm_pgoff; > +} > + > +static inline unsigned long vma_last_pgoff(struct vm_area_struct *v) > +{ > + return v->vm_pgoff + ((v->vm_end - v->vm_start) >> PAGE_SHIFT) - 1; > +} > + The pgoff computations are only for regular page, yes? > +INTERVAL_TREE_DEFINE(struct vm_area_struct, shared.linear.rb, > + unsigned long, shared.linear.rb_subtree_last, > + vma_start_pgoff, vma_last_pgoff,, vma_interval_tree) > + [...] > @@ -1547,7 +1545,6 @@ static int try_to_unmap_file(struct page *page, enum ttu_flags flags) > struct address_space *mapping = page->mapping; > pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT); What if page is huge? > struct vm_area_struct *vma; > - struct prio_tree_iter iter; > int ret = SWAP_AGAIN; > unsigned long cursor; > unsigned long max_nl_cursor = 0; > @@ -1555,7 +1552,7 @@ static int try_to_unmap_file(struct page *page, enum ttu_flags flags) > unsigned int mapcount; > > mutex_lock(&mapping->i_mmap_mutex); > - vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, pgoff, pgoff) { > + vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff) { > unsigned long address = vma_address(page, vma); > if (address == -EFAULT) > continue; -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>