1. 04 Oct, 2007 1 commit
    • Hugh Dickins's avatar
      Fix sys_remap_file_pages BUG at highmem.c:15! · 16abfa08
      Hugh Dickins authored
      Gurudas Pai reports kernel BUG at arch/i386/mm/highmem.c:15! below
      sys_remap_file_pages, while running Oracle database test on x86 in 6GB
      RAM: kunmap thinks we're in_interrupt because the preempt count has
      wrapped.
      
      That's because __do_fault expected to unmap page_table, but one of its
      two callers do_nonlinear_fault already unmapped it: let do_linear_fault
      unmap it first too, and then there's no need to pass the page_table arg
      down.
      
      Why have we been so slow to notice this? Probably through forgetting
      that the mapping_cap_account_dirty test means that sys_remap_file_pages
      nowadays only goes the full nonlinear vma route on a few memory-backed
      filesystems like ramfs, tmpfs and hugetlbfs.
      
      [ It also depends on CONFIG_HIGHPTE, so it becomes even harder to
        trigger in practice. Many who have need of large memory have probably
        migrated to x86-64..
      
        Problem introduced by commit d0217ac0
        ("mm: fault feedback #1")                -- Linus ]
      Signed-off-by: default avatarHugh Dickins <hugh@veritas.com>
      Cc: gurudas pai <gurudas.pai@oracle.com>
      Cc: Nick Piggin <nickpiggin@yahoo.com.au>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      16abfa08
  2. 03 Oct, 2007 15 commits
  3. 02 Oct, 2007 24 commits