diff options
| author | Pallipadi, Venkatesh <venkatesh.pallipadi@intel.com> | 2009-03-12 17:45:27 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-03-13 04:28:50 +0100 |
| commit | 4bb9c5c02153dfc89a6c73a6f32091413805ad7d (patch) | |
| tree | 408dee350cab80fbe7884b6640d651ef8ec44601 /include/linux | |
| parent | 6a5c05f002c3e4f24887a5fe8e7df757d339d368 (diff) | |
VM, x86, PAT: Change is_linear_pfn_mapping to not use vm_pgoff
Impact: fix false positive PAT warnings - also fix VirtalBox hang
Use of vma->vm_pgoff to identify the pfnmaps that are fully
mapped at mmap time is broken. vm_pgoff is set by generic mmap
code even for cases where drivers are setting up the mappings
at the fault time.
The problem was originally reported here:
http://marc.info/?l=linux-kernel&m=123383810628583&w=2
Change is_linear_pfn_mapping logic to overload VM_INSERTPAGE
flag along with VM_PFNMAP to mean full PFNMAP setup at mmap
time.
Problem also tracked at:
http://bugzilla.kernel.org/show_bug.cgi?id=12800
Reported-by: Thomas Hellstrom <thellstrom@vmware.com>
Tested-by: Frans Pop <elendil@planet.nl>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha>@intel.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: "ebiederm@xmission.com" <ebiederm@xmission.com>
Cc: <stable@kernel.org> # only for 2.6.29.1, not .28
LKML-Reference: <20090313004527.GA7176@linux-os.sc.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/mm.h | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index 065cdf8c09f..3daa05feed9 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -98,7 +98,7 @@ extern unsigned int kobjsize(const void *objp); #define VM_HUGETLB 0x00400000 /* Huge TLB Page VM */ #define VM_NONLINEAR 0x00800000 /* Is non-linear (remap_file_pages) */ #define VM_MAPPED_COPY 0x01000000 /* T if mapped copy of data (nommu mmap) */ -#define VM_INSERTPAGE 0x02000000 /* The vma has had "vm_insert_page()" done on it */ +#define VM_INSERTPAGE 0x02000000 /* The vma has had "vm_insert_page()" done on it. Refer note in VM_PFNMAP_AT_MMAP below */ #define VM_ALWAYSDUMP 0x04000000 /* Always include in core dumps */ #define VM_CAN_NONLINEAR 0x08000000 /* Has ->fault & does nonlinear pages */ @@ -127,6 +127,17 @@ extern unsigned int kobjsize(const void *objp); #define VM_SPECIAL (VM_IO | VM_DONTEXPAND | VM_RESERVED | VM_PFNMAP) /* + * pfnmap vmas that are fully mapped at mmap time (not mapped on fault). + * Used by x86 PAT to identify such PFNMAP mappings and optimize their handling. + * Note VM_INSERTPAGE flag is overloaded here. i.e, + * VM_INSERTPAGE && !VM_PFNMAP implies + * The vma has had "vm_insert_page()" done on it + * VM_INSERTPAGE && VM_PFNMAP implies + * The vma is PFNMAP with full mapping at mmap time + */ +#define VM_PFNMAP_AT_MMAP (VM_INSERTPAGE | VM_PFNMAP) + +/* * mapping from the currently active vm_flags protection bits (the * low four bits) to a page protection mask.. */ @@ -145,7 +156,7 @@ extern pgprot_t protection_map[16]; */ static inline int is_linear_pfn_mapping(struct vm_area_struct *vma) { - return ((vma->vm_flags & VM_PFNMAP) && vma->vm_pgoff); + return ((vma->vm_flags & VM_PFNMAP_AT_MMAP) == VM_PFNMAP_AT_MMAP); } static inline int is_pfn_mapping(struct vm_area_struct *vma) |