lkml.org 
[lkml]   [2008]   [Sep]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Date
    From
    Subject[PATCH 2/4] memcg: set page->mapping NULL before uncharge
    This patch tries to make page->mapping to be NULL before
    mem_cgroup_uncharge_cache_page() is called.

    "page->mapping == NULL" is a good check for "whether the page is still
    radix-tree or not".
    This patch also adds BUG_ON() to mem_cgroup_uncharge_cache_page();


    Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>

    mm/filemap.c | 2 +-
    mm/memcontrol.c | 1 +
    mm/migrate.c | 9 +++++++--
    3 files changed, 9 insertions(+), 3 deletions(-)

    Index: mmotm-2.6.27-rc7+/mm/filemap.c
    ===================================================================
    --- mmotm-2.6.27-rc7+.orig/mm/filemap.c
    +++ mmotm-2.6.27-rc7+/mm/filemap.c
    @@ -116,12 +116,12 @@ void __remove_from_page_cache(struct pag
    {
    struct address_space *mapping = page->mapping;

    - mem_cgroup_uncharge_cache_page(page);
    radix_tree_delete(&mapping->page_tree, page->index);
    page->mapping = NULL;
    mapping->nrpages--;
    __dec_zone_page_state(page, NR_FILE_PAGES);
    BUG_ON(page_mapped(page));
    + mem_cgroup_uncharge_cache_page(page);

    /*
    * Some filesystems seem to re-dirty the page even after
    Index: mmotm-2.6.27-rc7+/mm/memcontrol.c
    ===================================================================
    --- mmotm-2.6.27-rc7+.orig/mm/memcontrol.c
    +++ mmotm-2.6.27-rc7+/mm/memcontrol.c
    @@ -734,6 +734,7 @@ void mem_cgroup_uncharge_page(struct pag
    void mem_cgroup_uncharge_cache_page(struct page *page)
    {
    VM_BUG_ON(page_mapped(page));
    + VM_BUG_ON(page->mapping);
    __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_CACHE);
    }

    Index: mmotm-2.6.27-rc7+/mm/migrate.c
    ===================================================================
    --- mmotm-2.6.27-rc7+.orig/mm/migrate.c
    +++ mmotm-2.6.27-rc7+/mm/migrate.c
    @@ -330,8 +330,6 @@ static int migrate_page_move_mapping(str
    __inc_zone_page_state(newpage, NR_FILE_PAGES);

    spin_unlock_irq(&mapping->tree_lock);
    - if (!PageSwapCache(newpage))
    - mem_cgroup_uncharge_cache_page(page);

    return 0;
    }
    @@ -341,6 +339,8 @@ static int migrate_page_move_mapping(str
    */
    static void migrate_page_copy(struct page *newpage, struct page *page)
    {
    + int anon;
    +
    copy_highpage(newpage, page);

    if (PageError(page))
    @@ -378,8 +378,13 @@ static void migrate_page_copy(struct pag
    #endif
    ClearPagePrivate(page);
    set_page_private(page, 0);
    + /* page->mapping contains a flag for PageAnon() */
    + anon = PageAnon(page);
    page->mapping = NULL;

    + if (!anon) /* This page was removed from radix-tree. */
    + mem_cgroup_uncharge_cache_page(page);
    +
    /*
    * If any waiters have accumulated on the new page then
    * wake them up.


    \
     
     \ /
      Last update: 2008-09-29 12:19    [W:0.040 / U:34.888 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site