Eric Lee / smarc-fsl-linux-kernel

02 Nov, 2017

1 commit

  • b24413180   License cleanup: add SPDX GPL-2.0 license identifier to files with no license ... Browse Code »

    Many source files in the tree are missing licensing information, which
    makes it harder for compliance tools to determine the correct license.

    By default all files without license information are under the default
    license of the kernel, which is GPL version 2.

    Update the files which contain no license information with the 'GPL-2.0'
    SPDX license identifier. The SPDX identifier is a legally binding
    shorthand, which can be used instead of the full boiler plate text.

    This patch is based on work done by Thomas Gleixner and Kate Stewart and
    Philippe Ombredanne.

    How this work was done:

    Patches were generated and checked against linux-4.14-rc6 for a subset of
    the use cases:
    - file had no licensing information it it.
    - file was a */uapi/* one with no licensing information in it,
    - file was a */uapi/* one with existing licensing information,

    Further patches will be generated in subsequent months to fix up cases
    where non-standard license headers were used, and references to license
    had to be inferred by heuristics based on keywords.

    The analysis to determine which SPDX License Identifier to be applied to
    a file was done in a spreadsheet of side by side results from of the
    output of two independent scanners (ScanCode & Windriver) producing SPDX
    tag:value files created by Philippe Ombredanne. Philippe prepared the
    base worksheet, and did an initial spot review of a few 1000 files.

    The 4.13 kernel was the starting point of the analysis with 60,537 files
    assessed. Kate Stewart did a file by file comparison of the scanner
    results in the spreadsheet to determine which SPDX license identifier(s)
    to be applied to the file. She confirmed any determination that was not
    immediately clear with lawyers working with the Linux Foundation.

    Criteria used to select files for SPDX license identifier tagging was:
    - Files considered eligible had to be source code files.
    - Make and config files were included as candidates if they contained >5
    lines of source
    - File already had some variant of a license header in it (even if
    Reviewed-by: Philippe Ombredanne
    Reviewed-by: Thomas Gleixner
    Signed-off-by: Greg Kroah-Hartman

    Greg Kroah-Hartman
     

25 Feb, 2017

1 commit

  • 3a4f8a0b3   mm: remove shmem_mapping() shmem_zero_setup() duplicates ... Browse Code »

    Remove the prototypes for shmem_mapping() and shmem_zero_setup() from
    linux/mm.h, since they are already provided in linux/shmem_fs.h. But
    shmem_fs.h must then provide the inline stub for shmem_mapping() when
    CONFIG_SHMEM is not set, and a few more cfiles now need to #include it.

    Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1702081658250.1549@eggly.anvils
    Signed-off-by: Hugh Dickins
    Cc: Johannes Weiner
    Cc: Michal Simek
    Cc: Michael Ellerman
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Hugh Dickins
     

25 Dec, 2016

1 commit

08 Oct, 2016

1 commit

  • f6ab1f7f6   mm, swap: use offset of swap entry as key of swap cache ... Browse Code »

    This patch is to improve the performance of swap cache operations when
    the type of the swap device is not 0. Originally, the whole swap entry
    value is used as the key of the swap cache, even though there is one
    radix tree for each swap device. If the type of the swap device is not
    0, the height of the radix tree of the swap cache will be increased
    unnecessary, especially on 64bit architecture. For example, for a 1GB
    swap device on the x86_64 architecture, the height of the radix tree of
    the swap cache is 11. But if the offset of the swap entry is used as
    the key of the swap cache, the height of the radix tree of the swap
    cache is 4. The increased height causes unnecessary radix tree
    descending and increased cache footprint.

    This patch reduces the height of the radix tree of the swap cache via
    using the offset of the swap entry instead of the whole swap entry value
    as the key of the swap cache. In 32 processes sequential swap out test
    case on a Xeon E5 v3 system with RAM disk as swap, the lock contention
    for the spinlock of the swap cache is reduced from 20.15% to 12.19%,
    when the type of the swap device is 1.

    Use the whole swap entry as key,

    perf-profile.calltrace.cycles-pp._raw_spin_lock_irq.__add_to_swap_cache.add_to_swap_cache.add_to_swap.shrink_page_list: 10.37,
    perf-profile.calltrace.cycles-pp._raw_spin_lock_irqsave.__remove_mapping.shrink_page_list.shrink_inactive_list.shrink_node_memcg: 9.78,

    Use the swap offset as key,

    perf-profile.calltrace.cycles-pp._raw_spin_lock_irq.__add_to_swap_cache.add_to_swap_cache.add_to_swap.shrink_page_list: 6.25,
    perf-profile.calltrace.cycles-pp._raw_spin_lock_irqsave.__remove_mapping.shrink_page_list.shrink_inactive_list.shrink_node_memcg: 5.94,

    Link: http://lkml.kernel.org/r/1473270649-27229-1-git-send-email-ying.huang@intel.com
    Signed-off-by: "Huang, Ying"
    Cc: Johannes Weiner
    Cc: Michal Hocko
    Cc: Vladimir Davydov
    Cc: "Kirill A. Shutemov"
    Cc: Dave Hansen
    Cc: Dan Williams
    Cc: Joonsoo Kim
    Cc: Hugh Dickins
    Cc: Mel Gorman
    Cc: Minchan Kim
    Cc: Aaron Lu
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Huang Ying
     

05 Apr, 2016

2 commits

  • ea1754a08   mm, fs: remove remaining PAGE_CACHE_* and page_cache_{get,release} usage ... Browse Code »

    Mostly direct substitution with occasional adjustment or removing
    outdated comments.

    Signed-off-by: Kirill A. Shutemov
    Acked-by: Michal Hocko
    Signed-off-by: Linus Torvalds

    Kirill A. Shutemov
     
  • 09cbfeaf1   mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros ... Browse Code »

    PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
    ago with promise that one day it will be possible to implement page
    cache with bigger chunks than PAGE_SIZE.

    This promise never materialized. And unlikely will.

    We have many places where PAGE_CACHE_SIZE assumed to be equal to
    PAGE_SIZE. And it's constant source of confusion on whether
    PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
    especially on the border between fs and mm.

    Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
    breakage to be doable.

    Let's stop pretending that pages in page cache are special. They are
    not.

    The changes are pretty straight-forward:

    - << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> ;

    - >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> ;

    - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};

    - page_cache_get() -> get_page();

    - page_cache_release() -> put_page();

    This patch contains automated changes generated with coccinelle using
    script below. For some reason, coccinelle doesn't patch header files.
    I've called spatch for them manually.

    The only adjustment after coccinelle is revert of changes to
    PAGE_CAHCE_ALIGN definition: we are going to drop it later.

    There are few places in the code where coccinelle didn't reach. I'll
    fix them manually in a separate patch. Comments and documentation also
    will be addressed with the separate patch.

    virtual patch

    @@
    expression E;
    @@
    - E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
    + E

    @@
    expression E;
    @@
    - E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
    + E

    @@
    @@
    - PAGE_CACHE_SHIFT
    + PAGE_SHIFT

    @@
    @@
    - PAGE_CACHE_SIZE
    + PAGE_SIZE

    @@
    @@
    - PAGE_CACHE_MASK
    + PAGE_MASK

    @@
    expression E;
    @@
    - PAGE_CACHE_ALIGN(E)
    + PAGE_ALIGN(E)

    @@
    expression E;
    @@
    - page_cache_get(E)
    + get_page(E)

    @@
    expression E;
    @@
    - page_cache_release(E)
    + put_page(E)

    Signed-off-by: Kirill A. Shutemov
    Acked-by: Michal Hocko
    Signed-off-by: Linus Torvalds

    Kirill A. Shutemov
     

22 Jan, 2016

1 commit

  • b6ec57f4b   thp: change pmd_trans_huge_lock() interface to return ptl ... Browse Code »

    After THP refcounting rework we have only two possible return values
    from pmd_trans_huge_lock(): success and failure. Return-by-pointer for
    ptl doesn't make much sense in this case.

    Let's convert pmd_trans_huge_lock() to return ptl on success and NULL on
    failure.

    Signed-off-by: Kirill A. Shutemov
    Suggested-by: Linus Torvalds
    Cc: Minchan Kim
    Acked-by: Michal Hocko
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Kirill A. Shutemov
     

16 Jan, 2016

1 commit

  • 4b471e889   mm, thp: remove infrastructure for handling splitting PMDs ... Browse Code »

    With new refcounting we don't need to mark PMDs splitting. Let's drop
    code to handle this.

    Signed-off-by: Kirill A. Shutemov
    Tested-by: Sasha Levin
    Tested-by: Aneesh Kumar K.V
    Acked-by: Vlastimil Babka
    Acked-by: Jerome Marchand
    Cc: Andrea Arcangeli
    Cc: Hugh Dickins
    Cc: Dave Hansen
    Cc: Mel Gorman
    Cc: Rik van Riel
    Cc: Naoya Horiguchi
    Cc: Steve Capper
    Cc: Johannes Weiner
    Cc: Michal Hocko
    Cc: Christoph Lameter
    Cc: David Rientjes
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Kirill A. Shutemov
     

06 Nov, 2015

1 commit

12 Feb, 2015

1 commit

  • 1e25a271c   mincore: apply page table walker on do_mincore() ... Browse Code »

    This patch makes do_mincore() use walk_page_vma(), which reduces many
    lines of code by using common page table walk code.

    [daeseok.youn@gmail.com: remove unneeded variable 'err']
    Signed-off-by: Naoya Horiguchi
    Acked-by: Johannes Weiner
    Cc: "Kirill A. Shutemov"
    Cc: Andrea Arcangeli
    Cc: Cyrill Gorcunov
    Cc: Dave Hansen
    Cc: Kirill A. Shutemov
    Cc: Pavel Emelyanov
    Cc: Benjamin Herrenschmidt
    Signed-off-by: Daeseok Youn
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Naoya Horiguchi
     

11 Feb, 2015

1 commit

14 Dec, 2014

1 commit

  • c313dc5de   mm: mincore: add hwpoison page handle ... Browse Code »

    When the encountered pte is a swap entry, the current code handles two
    cases: migration and normal swapentry, but we have a third case: hwpoison
    page.

    This patch adds hwpoison page handle, consider hwpoison page incore as
    same as migration.

    [akpm@linux-foundation.org: coding-style fixes]
    Signed-off-by: Weijie Yang
    Acked-by: Johannes Weiner
    Cc: Mel Gorman
    Cc: Hugh Dickins
    Cc: Rik van Riel
    Acked-by: Naoya Horiguchi
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Weijie Yang
     

04 Apr, 2014

1 commit

  • 0cd6144aa   mm + fs: prepare for non-page entries in page cache radix trees ... Browse Code »

    shmem mappings already contain exceptional entries where swap slot
    information is remembered.

    To be able to store eviction information for regular page cache, prepare
    every site dealing with the radix trees directly to handle entries other
    than pages.

    The common lookup functions will filter out non-page entries and return
    NULL for page cache holes, just as before. But provide a raw version of
    the API which returns non-page entries as well, and switch shmem over to
    use it.

    Signed-off-by: Johannes Weiner
    Reviewed-by: Rik van Riel
    Reviewed-by: Minchan Kim
    Cc: Andrea Arcangeli
    Cc: Bob Liu
    Cc: Christoph Hellwig
    Cc: Dave Chinner
    Cc: Greg Thelen
    Cc: Hugh Dickins
    Cc: Jan Kara
    Cc: KOSAKI Motohiro
    Cc: Luigi Semenzato
    Cc: Mel Gorman
    Cc: Metin Doslu
    Cc: Michel Lespinasse
    Cc: Ozgun Erdogan
    Cc: Peter Zijlstra
    Cc: Roman Gushchin
    Cc: Ryan Mallon
    Cc: Tejun Heo
    Cc: Vlastimil Babka
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Johannes Weiner
     

24 Jan, 2014

1 commit

  • c980e66a5   mm: do_mincore() cleanup ... Browse Code »

    Two cleanups:
    1. remove redundant codes for hugetlb pages.
    2. end = pmd_addr_end(addr, end) restricts [addr, end) within PMD_SIZE,
    this may increase do_mincore() calls, remove it.

    Signed-off-by: Jianguo Wu
    Acked-by: Johannes Weiner
    Cc: Minchan Kim
    Cc: qiuxishi
    Reviewed-by: Naoya Horiguchi
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Jianguo Wu
     

24 Feb, 2013

1 commit

  • 33806f06d   swap: make each swap partition have one address_space ... Browse Code »

    When I use several fast SSD to do swap, swapper_space.tree_lock is
    heavily contended. This makes each swap partition have one
    address_space to reduce the lock contention. There is an array of
    address_space for swap. The swap entry type is the index to the array.

    In my test with 3 SSD, this increases the swapout throughput 20%.

    [akpm@linux-foundation.org: revert unneeded change to __add_to_swap_cache]
    Signed-off-by: Shaohua Li
    Cc: Hugh Dickins
    Acked-by: Rik van Riel
    Acked-by: Minchan Kim
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Shaohua Li
     

22 Mar, 2012

1 commit

  • 1a5a9906d   mm: thp: fix pmd_bad() triggering in code paths holding mmap_sem read mode ... Browse Code »
    1

    In some cases it may happen that pmd_none_or_clear_bad() is called with
    the mmap_sem hold in read mode. In those cases the huge page faults can
    allocate hugepmds under pmd_none_or_clear_bad() and that can trigger a
    false positive from pmd_bad() that will not like to see a pmd
    materializing as trans huge.

    It's not khugepaged causing the problem, khugepaged holds the mmap_sem
    in write mode (and all those sites must hold the mmap_sem in read mode
    to prevent pagetables to go away from under them, during code review it
    seems vm86 mode on 32bit kernels requires that too unless it's
    restricted to 1 thread per process or UP builds). The race is only with
    the huge pagefaults that can convert a pmd_none() into a
    pmd_trans_huge().

    Effectively all these pmd_none_or_clear_bad() sites running with
    mmap_sem in read mode are somewhat speculative with the page faults, and
    the result is always undefined when they run simultaneously. This is
    probably why it wasn't common to run into this. For example if the
    madvise(MADV_DONTNEED) runs zap_page_range() shortly before the page
    fault, the hugepage will not be zapped, if the page fault runs first it
    will be zapped.

    Altering pmd_bad() not to error out if it finds hugepmds won't be enough
    to fix this, because zap_pmd_range would then proceed to call
    zap_pte_range (which would be incorrect if the pmd become a
    pmd_trans_huge()).

    The simplest way to fix this is to read the pmd in the local stack
    (regardless of what we read, no need of actual CPU barriers, only
    compiler barrier needed), and be sure it is not changing under the code
    that computes its value. Even if the real pmd is changing under the
    value we hold on the stack, we don't care. If we actually end up in
    zap_pte_range it means the pmd was not none already and it was not huge,
    and it can't become huge from under us (khugepaged locking explained
    above).

    All we need is to enforce that there is no way anymore that in a code
    path like below, pmd_trans_huge can be false, but pmd_none_or_clear_bad
    can run into a hugepmd. The overhead of a barrier() is just a compiler
    tweak and should not be measurable (I only added it for THP builds). I
    don't exclude different compiler versions may have prevented the race
    too by caching the value of *pmd on the stack (that hasn't been
    verified, but it wouldn't be impossible considering
    pmd_none_or_clear_bad, pmd_bad, pmd_trans_huge, pmd_none are all inlines
    and there's no external function called in between pmd_trans_huge and
    pmd_none_or_clear_bad).

    if (pmd_trans_huge(*pmd)) {
    if (next-addr != HPAGE_PMD_SIZE) {
    VM_BUG_ON(!rwsem_is_locked(&tlb->mm->mmap_sem));
    split_huge_page_pmd(vma->vm_mm, pmd);
    } else if (zap_huge_pmd(tlb, vma, pmd, addr))
    continue;
    /* fall through */
    }
    if (pmd_none_or_clear_bad(pmd))

    Because this race condition could be exercised without special
    privileges this was reported in CVE-2012-1179.

    The race was identified and fully explained by Ulrich who debugged it.
    I'm quoting his accurate explanation below, for reference.

    ====== start quote =======
    mapcount 0 page_mapcount 1
    kernel BUG at mm/huge_memory.c:1384!

    At some point prior to the panic, a "bad pmd ..." message similar to the
    following is logged on the console:

    mm/memory.c:145: bad pmd ffff8800376e1f98(80000000314000e7).

    The "bad pmd ..." message is logged by pmd_clear_bad() before it clears
    the page's PMD table entry.

    143 void pmd_clear_bad(pmd_t *pmd)
    144 {
    -> 145 pmd_ERROR(*pmd);
    146 pmd_clear(pmd);
    147 }

    After the PMD table entry has been cleared, there is an inconsistency
    between the actual number of PMD table entries that are mapping the page
    and the page's map count (_mapcount field in struct page). When the page
    is subsequently reclaimed, __split_huge_page() detects this inconsistency.

    1381 if (mapcount != page_mapcount(page))
    1382 printk(KERN_ERR "mapcount %d page_mapcount %d\n",
    1383 mapcount, page_mapcount(page));
    -> 1384 BUG_ON(mapcount != page_mapcount(page));

    The root cause of the problem is a race of two threads in a multithreaded
    process. Thread B incurs a page fault on a virtual address that has never
    been accessed (PMD entry is zero) while Thread A is executing an madvise()
    system call on a virtual address within the same 2 MB (huge page) range.

    virtual address space
    .---------------------.
    | |
    | |
    .-|---------------------|
    | | |
    | | |< |/////////////////////| > A(range)
    page | |/////////////////////|-'
    | | |
    | | |
    '-|---------------------|
    | |
    | |
    '---------------------'

    - Thread A is executing an madvise(..., MADV_DONTNEED) system call
    on the virtual address range "A(range)" shown in the picture.

    sys_madvise
    // Acquire the semaphore in shared mode.
    down_read(¤t->mm->mmap_sem)
    ...
    madvise_vma
    switch (behavior)
    case MADV_DONTNEED:
    madvise_dontneed
    zap_page_range
    unmap_vmas
    unmap_page_range
    zap_pud_range
    zap_pmd_range
    //
    // Assume that this huge page has never been accessed.
    // I.e. content of the PMD entry is zero (not mapped).
    //
    if (pmd_trans_huge(*pmd)) {
    // We don't get here due to the above assumption.
    }
    //
    // Assume that Thread B incurred a page fault and
    .---------> // sneaks in here as shown below.
    | //
    | if (pmd_none_or_clear_bad(pmd))
    | {
    | if (unlikely(pmd_bad(*pmd)))
    | pmd_clear_bad
    | {
    | pmd_ERROR
    | // Log "bad pmd ..." message here.
    | pmd_clear
    | // Clear the page's PMD entry.
    | // Thread B incremented the map count
    | // in page_add_new_anon_rmap(), but
    | // now the page is no longer mapped
    | // by a PMD entry (-> inconsistency).
    | }
    | }
    |
    v
    - Thread B is handling a page fault on virtual address "B(fault)" shown
    in the picture.

    ...
    do_page_fault
    __do_page_fault
    // Acquire the semaphore in shared mode.
    down_read_trylock(&mm->mmap_sem)
    ...
    handle_mm_fault
    if (pmd_none(*pmd) && transparent_hugepage_enabled(vma))
    // We get here due to the above assumption (PMD entry is zero).
    do_huge_pmd_anonymous_page
    alloc_hugepage_vma
    // Allocate a new transparent huge page here.
    ...
    __do_huge_pmd_anonymous_page
    ...
    spin_lock(&mm->page_table_lock)
    ...
    page_add_new_anon_rmap
    // Here we increment the page's map count (starts at -1).
    atomic_set(&page->_mapcount, 0)
    set_pmd_at
    // Here we set the page's PMD entry which will be cleared
    // when Thread A calls pmd_clear_bad().
    ...
    spin_unlock(&mm->page_table_lock)

    The mmap_sem does not prevent the race because both threads are acquiring
    it in shared mode (down_read). Thread B holds the page_table_lock while
    the page's map count and PMD table entry are updated. However, Thread A
    does not synchronize on that lock.

    ====== end quote =======

    [akpm@linux-foundation.org: checkpatch fixes]
    Reported-by: Ulrich Obergfell
    Signed-off-by: Andrea Arcangeli
    Acked-by: Johannes Weiner
    Cc: Mel Gorman
    Cc: Hugh Dickins
    Cc: Dave Jones
    Acked-by: Larry Woodman
    Acked-by: Rik van Riel
    Cc: [2.6.38+]
    Cc: Mark Salter
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Andrea Arcangeli
     

04 Aug, 2011

2 commits

  • 8079b1c85   mm: clarify the radix_tree exceptional cases ... Browse Code »

    Make the radix_tree exceptional cases, mostly in filemap.c, clearer.

    It's hard to devise a suitable snappy name that illuminates the use by
    shmem/tmpfs for swap, while keeping filemap/pagecache/radix_tree
    generality. And akpm points out that /* radix_tree_deref_retry(page) */
    comments look like calls that have been commented out for unknown
    reason.

    Skirt the naming difficulty by rearranging these blocks to handle the
    transient radix_tree_deref_retry(page) case first; then just explain the
    remaining shmem/tmpfs swap case in a comment.

    Signed-off-by: Hugh Dickins
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Hugh Dickins
     
  • 31475dd61   mm: a few small updates for radix-swap ... Browse Code »

    Remove PageSwapBacked (!page_is_file_cache) cases from
    add_to_page_cache_locked() and add_to_page_cache_lru(): those pages now
    go through shmem_add_to_page_cache().

    Remove a comment on maximum tmpfs size from fsstack_copy_inode_size(),
    and add a comment on swap entries to invalidate_mapping_pages().

    And mincore_page() uses find_get_page() on what might be shmem or a
    tmpfs file: allow for a radix_tree_exceptional_entry(), and proceed to
    find_get_page() on swapper_space if so (oh, swapper_space needs #ifdef).

    Signed-off-by: Hugh Dickins
    Acked-by: Rik van Riel
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Hugh Dickins
     

14 Jan, 2011

2 commits

  • 0ca1634d4   thp: mincore transparent hugepage support ... Browse Code »

    Handle transparent huge page pmd entries natively instead of splitting
    them into subpages.

    Signed-off-by: Johannes Weiner
    Signed-off-by: Andrea Arcangeli
    Reviewed-by: Rik van Riel
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Johannes Weiner
     
  • bae9c19bf   thp: split_huge_page_mm/vma ... Browse Code »

    split_huge_page_pmd compat code. Each one of those would need to be
    expanded to hundred of lines of complex code without a fully reliable
    split_huge_page_pmd design.

    Signed-off-by: Andrea Arcangeli
    Acked-by: Rik van Riel
    Acked-by: Mel Gorman
    Signed-off-by: Johannes Weiner
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Andrea Arcangeli
     

25 May, 2010

4 commits

  • e48293fd7   mincore: do nested page table walks ... Browse Code »

    Do page table walks with the well-known nested loops we use in several
    other places already.

    This avoids doing full page table walks after every pte range and also
    allows to handle unmapped areas bigger than one pte range in one go.

    Signed-off-by: Johannes Weiner
    Cc: Andrea Arcangeli
    Cc: Naoya Horiguchi
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Johannes Weiner
     
  • 25ef0e50c   mincore: pass ranges as start,end address pairs ... Browse Code »

    Instead of passing a start address and a number of pages into the helper
    functions, convert them to use a start and an end address.

    Signed-off-by: Johannes Weiner
    Cc: Andrea Arcangeli
    Cc: Naoya Horiguchi
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Johannes Weiner
     
  • f48840107   mincore: break do_mincore() into logical pieces ... Browse Code »

    Split out functions to handle hugetlb ranges, pte ranges and unmapped
    ranges, to improve readability but also to prepare the file structure for
    nested page table walks.

    No semantic changes intended.

    Signed-off-by: Johannes Weiner
    Cc: Andrea Arcangeli
    Cc: Naoya Horiguchi
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Johannes Weiner
     
  • 6a60f1b35   mincore: cleanups ... Browse Code »

    This fixes some minor issues that bugged me while going over the code:

    o adjust argument order of do_mincore() to match the syscall
    o simplify range length calculation
    o drop superfluous shift in huge tlb calculation, address is page aligned
    o drop dead nr_huge calculation
    o check pte_none() before pte_present()
    o comment and whitespace fixes

    No semantic changes intended.

    Signed-off-by: Johannes Weiner
    Cc: Andrea Arcangeli
    Cc: Naoya Horiguchi
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Johannes Weiner
     

30 Mar, 2010

1 commit

  • 5a0e3ad6a   include cleanup: Update gfp.h and slab.h includes to prepare for breaking implic… ... Browse Code »

    …it slab.h inclusion from percpu.h

    percpu.h is included by sched.h and module.h and thus ends up being
    included when building most .c files. percpu.h includes slab.h which
    in turn includes gfp.h making everything defined by the two files
    universally available and complicating inclusion dependencies.

    percpu.h -> slab.h dependency is about to be removed. Prepare for
    this change by updating users of gfp and slab facilities include those
    headers directly instead of assuming availability. As this conversion
    needs to touch large number of source files, the following script is
    used as the basis of conversion.

    http://userweb.kernel.org/~tj/misc/slabh-sweep.py

    The script does the followings.

    * Scan files for gfp and slab usages and update includes such that
    only the necessary includes are there. ie. if only gfp is used,
    gfp.h, if slab is used, slab.h.

    * When the script inserts a new include, it looks at the include
    blocks and try to put the new include such that its order conforms
    to its surrounding. It's put in the include block which contains
    core kernel includes, in the same order that the rest are ordered -
    alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
    doesn't seem to be any matching order.

    * If the script can't find a place to put a new include (mostly
    because the file doesn't have fitting include block), it prints out
    an error message indicating which .h file needs to be added to the
    file.

    The conversion was done in the following steps.

    1. The initial automatic conversion of all .c files updated slightly
    over 4000 files, deleting around 700 includes and adding ~480 gfp.h
    and ~3000 slab.h inclusions. The script emitted errors for ~400
    files.

    2. Each error was manually checked. Some didn't need the inclusion,
    some needed manual addition while adding it to implementation .h or
    embedding .c file was more appropriate for others. This step added
    inclusions to around 150 files.

    3. The script was run again and the output was compared to the edits
    from #2 to make sure no file was left behind.

    4. Several build tests were done and a couple of problems were fixed.
    e.g. lib/decompress_*.c used malloc/free() wrappers around slab
    APIs requiring slab.h to be added manually.

    5. The script was run on all .h files but without automatically
    editing them as sprinkling gfp.h and slab.h inclusions around .h
    files could easily lead to inclusion dependency hell. Most gfp.h
    inclusion directives were ignored as stuff from gfp.h was usually
    wildly available and often used in preprocessor macros. Each
    slab.h inclusion directive was examined and added manually as
    necessary.

    6. percpu.h was updated not to include slab.h.

    7. Build test were done on the following configurations and failures
    were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
    distributed build env didn't work with gcov compiles) and a few
    more options had to be turned off depending on archs to make things
    build (like ipr on powerpc/64 which failed due to missing writeq).

    * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
    * powerpc and powerpc64 SMP allmodconfig
    * sparc and sparc64 SMP allmodconfig
    * ia64 SMP allmodconfig
    * s390 SMP allmodconfig
    * alpha SMP allmodconfig
    * um on x86_64 SMP allmodconfig

    8. percpu.h modifications were reverted so that it could be applied as
    a separate patch and serve as bisection point.

    Given the fact that I had only a couple of failures from tests on step
    6, I'm fairly confident about the coverage of this conversion patch.
    If there is a breakage, it's likely to be something in one of the arch
    headers which should be easily discoverable easily on most builds of
    the specific arch.

    Signed-off-by: Tejun Heo <tj@kernel.org>
    Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
    Cc: Ingo Molnar <mingo@redhat.com>
    Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

    Tejun Heo
     

16 Dec, 2009

1 commit

  • 4f16fc107   mm: hugetlb: fix hugepage memory leak in mincore() ... Browse Code »

    Most callers of pmd_none_or_clear_bad() check whether the target page is
    in a hugepage or not, but mincore() and walk_page_range() do not check it.
    So if we use mincore() on a hugepage on x86 machine, the hugepage memory
    is leaked as shown below. This patch fixes it by extending mincore()
    system call to support hugepages.

    Details
    =======
    My test program (leak_mincore) works as follows:
    - creat() and mmap() a file on hugetlbfs (file size is 200MB == 100 hugepages,)
    - read()/write() something on it,
    - call mincore() for first ten pages and printf() the values of *vec
    - munmap() and unlink() the file on hugetlbfs

    Without my patch
    ----------------
    $ cat /proc/meminfo| grep "HugePage"
    HugePages_Total: 1000
    HugePages_Free: 1000
    HugePages_Rsvd: 0
    HugePages_Surp: 0
    $ ./leak_mincore
    vec[0] 0
    vec[1] 0
    vec[2] 0
    vec[3] 0
    vec[4] 0
    vec[5] 0
    vec[6] 0
    vec[7] 0
    vec[8] 0
    vec[9] 0
    $ cat /proc/meminfo |grep "HugePage"
    HugePages_Total: 1000
    HugePages_Free: 999
    HugePages_Rsvd: 0
    HugePages_Surp: 0
    $ ls /hugetlbfs/
    $

    Return values in *vec from mincore() are set to 0, while the hugepage
    should be in memory, and 1 hugepage is still accounted as used while
    there is no file on hugetlbfs.

    With my patch
    -------------
    $ cat /proc/meminfo| grep "HugePage"
    HugePages_Total: 1000
    HugePages_Free: 1000
    HugePages_Rsvd: 0
    HugePages_Surp: 0
    $ ./leak_mincore
    vec[0] 1
    vec[1] 1
    vec[2] 1
    vec[3] 1
    vec[4] 1
    vec[5] 1
    vec[6] 1
    vec[7] 1
    vec[8] 1
    vec[9] 1
    $ cat /proc/meminfo |grep "HugePage"
    HugePages_Total: 1000
    HugePages_Free: 1000
    HugePages_Rsvd: 0
    HugePages_Surp: 0
    $ ls /hugetlbfs/
    $

    Return value in *vec set to 1 and no memory leaks.

    [akpm@linux-foundation.org: cleanup]
    [akpm@linux-foundation.org: build fix]
    Signed-off-by: Naoya Horiguchi
    Cc: Andi Kleen
    Cc: Wu Fengguang
    Cc: Hugh Dickins
    Cc: Mel Gorman
    Cc: Lee Schermerhorn
    Cc: Andy Whitcroft
    Cc: David Rientjes
    Cc:
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Naoya Horiguchi
     

14 Jan, 2009

1 commit

28 Apr, 2008

1 commit

  • 3c18ddd16   mm: remove nopage ... Browse Code »

    Nothing in the tree uses nopage any more. Remove support for it in the
    core mm code and documentation (and a few stray references to it in
    comments).

    Signed-off-by: Nick Piggin
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Nick Piggin
     

16 Feb, 2007

3 commits

13 Feb, 2007

1 commit

  • 42da9cbd3   [PATCH] mm: mincore anon ... Browse Code »

    Make mincore work for anon mappings, nonlinear, and migration entries.
    Based on patch from Linus Torvalds .

    Signed-off-by: Nick Piggin
    Acked-by: Hugh Dickins
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Nick Piggin
     

18 Dec, 2006

1 commit

17 Dec, 2006

2 commits

  • 4fb23e439   Fix up mm/mincore.c error value cases ... Browse Code »

    Hugh Dickins correctly points out that mincore() is actually _supposed_
    to fail on an unmapped hole in the user address space, rather than
    return valid ("empty") information about the hole. This just simplifies
    the problem further (I had been misled by our previous confusing and
    complicated way of doing mincore()).

    Also, in the unlikely situation that we can't allocate a temporary
    kernel buffer, we should actually return EAGAIN, not ENOMEM, to keep the
    "unmapped hole" and "allocation failure" error cases separate.

    Finally, add a comment about our stupid historical lack of support for
    anonymous mappings. I'll fix that if somebody reminds me after 2.6.20
    is out.

    Acked-by: Hugh Dickins
    Signed-off-by: Linus Torvalds

    Linus Torvalds
     
  • 2f77d1070   Fix incorrect user space access locking in mincore() ... Browse Code »

    Doug Chapman noticed that mincore() will doa "copy_to_user()" of the
    result while holding the mmap semaphore for reading, which is a big
    no-no. While a recursive read-lock on a semaphore in the case of a page
    fault happens to work, we don't actually allow them due to deadlock
    schenarios with writers due to fairness issues.

    Doug and Marcel sent in a patch to fix it, but I decided to just rewrite
    the mess instead - not just fixing the locking problem, but making the
    code smaller and (imho) much easier to understand.

    Cc: Doug Chapman
    Cc: Marcel Holtmann
    Cc: Hugh Dickins
    Cc: Andrew Morton
    Signed-off-by: Linus Torvalds

    Linus Torvalds
     

20 Apr, 2005

1 commit

  • 8462e2017   [PATCH] freepgt: sys_mincore ignore FIRST_USER_PGD_NR ... Browse Code »

    Remove use of FIRST_USER_PGD_NR from sys_mincore: it's inconsistent (no other
    syscall refers to it), unnecessary (sys_mincore loops over vmas further down)
    and incorrect (misses user addresses in ARM's first pgd).

    Signed-off-by: Hugh Dickins
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Hugh Dickins
     

17 Apr, 2005

1 commit

  • 1da177e4c   Linux-2.6.12-rc2 ... Browse Code »

    Initial git repository build. I'm not bothering with the full history,
    even though we have it. We can create a separate "historical" git
    archive of that later if we want to, and in the meantime it's about
    3.2GB when imported into git - space that would just make the early
    git days unnecessarily complicated, when we don't have a lot of good
    infrastructure for it.

    Let it rip!

    Linus Torvalds