summaryrefslogtreecommitdiff
path: root/mm/pagewalk.c
AgeCommit message (Collapse)Author
2009-12-18mm: hugetlb: fix hugepage memory leak in walk_page_range()Naoya Horiguchi
commit d33b9f45bd24a6391bc05e2b5a13c1b5787ca9c2 upstream. Most callers of pmd_none_or_clear_bad() check whether the target page is in a hugepage or not, but walk_page_range() do not check it. So if we read /proc/pid/pagemap for the hugepage on x86 machine, the hugepage memory is leaked as shown below. This patch fixes it. Details ======= My test program (leak_pagemap) works as follows: - creat() and mmap() a file on hugetlbfs (file size is 200MB == 100 hugepages,) - read()/write() something on it, - call page-types with option -p (walk around the page tables), - munmap() and unlink() the file on hugetlbfs Without my patches ------------------ $ cat /proc/meminfo |grep "HugePage" HugePages_Total: 1000 HugePages_Free: 1000 HugePages_Rsvd: 0 HugePages_Surp: 0 $ ./leak_pagemap [snip output] $ cat /proc/meminfo |grep "HugePage" HugePages_Total: 1000 HugePages_Free: 900 HugePages_Rsvd: 0 HugePages_Surp: 0 $ ls /hugetlbfs/ $ 100 hugepages are accounted as used while there is no file on hugetlbfs. With my patches --------------- $ cat /proc/meminfo |grep "HugePage" HugePages_Total: 1000 HugePages_Free: 1000 HugePages_Rsvd: 0 HugePages_Surp: 0 $ ./leak_pagemap [snip output] $ cat /proc/meminfo |grep "HugePage" HugePages_Total: 1000 HugePages_Free: 1000 HugePages_Rsvd: 0 HugePages_Surp: 0 $ ls /hugetlbfs $ No memory leaks. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Andy Whitcroft <apw@canonical.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-06-12pagemap: pass mm into pagewalkersDave Hansen
We need this at least for huge page detection for now, because powerpc needs the vm_area_struct to be able to determine whether a virtual address is referring to a huge page (its pmd_huge() doesn't work). It might also come in handy for some of the other users. Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com> Acked-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28mm: fix possible off-by-one in walk_pte_range()Johannes Weiner
After the loop in walk_pte_range() pte might point to the first address after the pmd it walks. The pte_unmap() is then applied to something bad. Spotted by Roel Kluin and Andreas Schwab. Signed-off-by: Johannes Weiner <hannes@saeurebad.de> Cc: Roel Kluin <12o3l@tiscali.nl> Cc: Andreas Schwab <schwab@suse.de> Acked-by: Matt Mackall <mpm@selenic.com> Acked-by: Mikael Pettersson <mikpe@it.uu.se> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-19mm: fix various kernel-doc commentsRandy Dunlap
Fix various kernel-doc notation in mm/: filemap.c: add function short description; convert 2 to kernel-doc fremap.c: change parameter 'prot' to @prot pagewalk.c: change "-" in function parameters to ":" slab.c: fix short description of kmem_ptr_validate() swap.c: fix description & parameters of put_pages_list() swap_state.c: fix function parameters vmalloc.c: change "@returns" to "Returns:" since that is not a parameter Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05maps4: introduce a generic page walkerMatt Mackall
Introduce a general page table walker Signed-off-by: Matt Mackall <mpm@selenic.com> Cc: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>