Patch from Hugh Dickins <hugh@veritas.com>
1. Revert MAP_NONLINEAR and VM_NONLINEAR: I can easily imagine wanting
VM_NONLINEAR in future, warning that vma is unusual, but currently it's
not useful: install_page just needs to SetPageAnon if the page is put
somewhere try_to_unmap_obj_one wouldn't be able to find it.
2. filemap_populate and shmem_populate expect an absolute pgoff, but
try_to_unmap_one is forgetting to add in vm_pgoff when doing set_pte.
Could be done the other way round, with relative pgoff in the pte?
No, that would make splitting a vma tedious.
3. No patch included, but I believe 2.5.64-mm1 is testing Ingo's
file-offset-in-pte very much less than you imagine (I've yet to hit
a breakpoint on do_file_page, and I don't think that's down to the
patches above): Dave's work means that the file pages don't arrive
at Ingo's code to set the pte with file offset (unless you actually
use Ingo's syscall) - difficult to test both at once, I think.
include/asm-i386/mman.h | 1 -
include/asm-ppc64/mman.h | 1 -
include/linux/mm.h | 1 -
mm/fremap.c | 9 ++++++---
mm/mmap.c | 1 -
mm/rmap.c | 2 ++
6 files changed, 8 insertions(+), 7 deletions(-)
diff -puN include/asm-i386/mman.h~hugh-nonlinear-fixes include/asm-i386/mman.h
--- 25/include/asm-i386/mman.h~hugh-nonlinear-fixes 2003-03-06 18:41:47.000000000 -0800
+++ 25-akpm/include/asm-i386/mman.h 2003-03-06 18:41:47.000000000 -0800
@@ -20,7 +20,6 @@
#define MAP_NORESERVE 0x4000 /* don't check for reservations */
#define MAP_POPULATE 0x8000 /* populate (prefault) pagetables */
#define MAP_NONBLOCK 0x10000 /* do not block on IO */
-#define MAP_NONLINEAR 0x20000 /* will be used for remap_file_pages */
#define MS_ASYNC 1 /* sync memory asynchronously */
#define MS_INVALIDATE 2 /* invalidate the caches */
diff -puN include/asm-ppc64/mman.h~hugh-nonlinear-fixes include/asm-ppc64/mman.h
--- 25/include/asm-ppc64/mman.h~hugh-nonlinear-fixes 2003-03-06 18:41:47.000000000 -0800
+++ 25-akpm/include/asm-ppc64/mman.h 2003-03-06 18:41:47.000000000 -0800
@@ -36,7 +36,6 @@
#define MAP_POPULATE 0x8000 /* populate (prefault) pagetables */
#define MAP_NONBLOCK 0x10000 /* do not block on IO */
-#define MAP_NONLINEAR 0x20000 /* Mapping may use remap_file_pages */
#define MADV_NORMAL 0x0 /* default page-in behavior */
#define MADV_RANDOM 0x1 /* page-in minimum required */
diff -puN include/linux/mm.h~hugh-nonlinear-fixes include/linux/mm.h
--- 25/include/linux/mm.h~hugh-nonlinear-fixes 2003-03-06 18:41:47.000000000 -0800
+++ 25-akpm/include/linux/mm.h 2003-03-06 18:41:47.000000000 -0800
@@ -107,7 +107,6 @@ struct vm_area_struct {
#define VM_RESERVED 0x00080000 /* Don't unmap it from swap_out */
#define VM_ACCOUNT 0x00100000 /* Is a VM accounted object */
#define VM_HUGETLB 0x00400000 /* Huge TLB Page VM */
-#define VM_NONLINEAR 0x00800000 /* Nonlinear area */
#ifdef CONFIG_STACK_GROWSUP
#define VM_STACK_FLAGS (VM_GROWSUP | VM_DATA_DEFAULT_FLAGS | VM_ACCOUNT)
diff -puN mm/fremap.c~hugh-nonlinear-fixes mm/fremap.c
--- 25/mm/fremap.c~hugh-nonlinear-fixes 2003-03-06 18:41:47.000000000 -0800
+++ 25-akpm/mm/fremap.c 2003-03-06 18:41:51.000000000 -0800
@@ -57,6 +57,7 @@ int install_page(struct mm_struct *mm, s
pgd_t *pgd;
pmd_t *pmd;
struct pte_chain *pte_chain;
+ unsigned long pgidx;
pte_chain = pte_chain_alloc(GFP_KERNEL);
if (!pte_chain)
@@ -79,7 +80,10 @@ int install_page(struct mm_struct *mm, s
flush_icache_page(vma, page);
entry = mk_pte(page, prot);
set_pte(pte, entry);
- if (vma->vm_flags & VM_NONLINEAR)
+ pgidx = (addr - vma->vm_start) >> PAGE_SHIFT;
+ pgidx += vma->vm_pgoff;
+ pgidx >>= PAGE_CACHE_SHIFT - PAGE_SHIFT;
+ if (page->index != pgidx)
SetPageAnon(page);
pte_chain = page_add_rmap(page, pte, pte_chain);
pte_unmap(pte);
@@ -139,8 +143,7 @@ int sys_remap_file_pages(unsigned long s
* and that the remapped range is valid and fully within
* the single existing vma:
*/
- if (vma &&
- ((vma->vm_flags & (VM_SHARED|VM_NONLINEAR)) == (VM_SHARED|VM_NONLINEAR)) &&
+ if (vma && (vma->vm_flags & VM_SHARED) &&
vma->vm_ops && vma->vm_ops->populate &&
end > start && start >= vma->vm_start &&
end <= vma->vm_end)
diff -puN mm/mmap.c~hugh-nonlinear-fixes mm/mmap.c
--- 25/mm/mmap.c~hugh-nonlinear-fixes 2003-03-06 18:41:47.000000000 -0800
+++ 25-akpm/mm/mmap.c 2003-03-06 18:41:51.000000000 -0800
@@ -219,7 +219,6 @@ calc_vm_flags(unsigned long prot, unsign
flag_bits =
_trans(flags, MAP_GROWSDOWN, VM_GROWSDOWN) |
_trans(flags, MAP_DENYWRITE, VM_DENYWRITE) |
- _trans(flags, MAP_NONLINEAR, VM_NONLINEAR) |
_trans(flags, MAP_EXECUTABLE, VM_EXECUTABLE);
return prot_bits | flag_bits;
#undef _trans
diff -puN mm/rmap.c~hugh-nonlinear-fixes mm/rmap.c
--- 25/mm/rmap.c~hugh-nonlinear-fixes 2003-03-06 18:41:47.000000000 -0800
+++ 25-akpm/mm/rmap.c 2003-03-06 18:41:51.000000000 -0800
@@ -598,6 +598,8 @@ static int try_to_unmap_one(struct page
* in the pte.
*/
pgidx = (address - vma->vm_start) >> PAGE_SHIFT;
+ pgidx += vma->vm_pgoff;
+ pgidx >>= PAGE_CACHE_SHIFT - PAGE_SHIFT;
if (1 || page->index != pgidx) {
set_pte(ptep, pgoff_to_pte(page->index));
BUG_ON(!pte_file(*ptep));
_