lkml.org 
[lkml]   [2020]   [Mar]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH v3 7/9] mm/swap: implement workingset detection for anonymous LRU
    Date
    From: Joonsoo Kim <iamjoonsoo.kim@lge.com>

    This patch implements workingset detection for anonymous LRU.
    All the infrastructure is implemented by the previous patches so this patch
    just activates the workingset detection by installing/retrieving
    the shadow entry.

    Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
    ---
    include/linux/swap.h | 11 +++++++++--
    mm/memory.c | 7 ++++++-
    mm/shmem.c | 3 ++-
    mm/swap_state.c | 31 ++++++++++++++++++++++++++-----
    mm/vmscan.c | 7 +++++--
    5 files changed, 48 insertions(+), 11 deletions(-)

    diff --git a/include/linux/swap.h b/include/linux/swap.h
    index 0df8b3f..fb4772e 100644
    --- a/include/linux/swap.h
    +++ b/include/linux/swap.h
    @@ -408,7 +408,9 @@ extern struct address_space *swapper_spaces[];
    extern unsigned long total_swapcache_pages(void);
    extern void show_swap_cache_info(void);
    extern int add_to_swap(struct page *page);
    -extern int add_to_swap_cache(struct page *, swp_entry_t, gfp_t);
    +extern void *get_shadow_from_swap_cache(swp_entry_t entry);
    +extern int add_to_swap_cache(struct page *page, swp_entry_t entry,
    + gfp_t gfp, void **shadowp);
    extern int __add_to_swap_cache(struct page *page, swp_entry_t entry);
    extern void __delete_from_swap_cache(struct page *page,
    swp_entry_t entry, void *shadow);
    @@ -565,8 +567,13 @@ static inline int add_to_swap(struct page *page)
    return 0;
    }

    +static inline void *get_shadow_from_swap_cache(swp_entry_t entry)
    +{
    + return NULL;
    +}
    +
    static inline int add_to_swap_cache(struct page *page, swp_entry_t entry,
    - gfp_t gfp_mask)
    + gfp_t gfp_mask, void **shadowp)
    {
    return -1;
    }
    diff --git a/mm/memory.c b/mm/memory.c
    index 5f7813a..91a2097 100644
    --- a/mm/memory.c
    +++ b/mm/memory.c
    @@ -2925,10 +2925,15 @@ vm_fault_t do_swap_page(struct vm_fault *vmf)
    page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma,
    vmf->address);
    if (page) {
    + void *shadow;
    +
    __SetPageLocked(page);
    __SetPageSwapBacked(page);
    set_page_private(page, entry.val);
    - lru_cache_add_anon(page);
    + shadow = get_shadow_from_swap_cache(entry);
    + if (shadow)
    + workingset_refault(page, shadow);
    + lru_cache_add(page);
    swap_readpage(page, true);
    }
    } else {
    diff --git a/mm/shmem.c b/mm/shmem.c
    index 8793e8c..c6663ad 100644
    --- a/mm/shmem.c
    +++ b/mm/shmem.c
    @@ -1370,7 +1370,8 @@ static int shmem_writepage(struct page *page, struct writeback_control *wbc)
    list_add(&info->swaplist, &shmem_swaplist);

    if (add_to_swap_cache(page, swap,
    - __GFP_HIGH | __GFP_NOMEMALLOC | __GFP_NOWARN) == 0) {
    + __GFP_HIGH | __GFP_NOMEMALLOC | __GFP_NOWARN,
    + NULL) == 0) {
    spin_lock_irq(&info->lock);
    shmem_recalc_inode(inode);
    info->swapped++;
    diff --git a/mm/swap_state.c b/mm/swap_state.c
    index 3fbbe45..7f7cb19 100644
    --- a/mm/swap_state.c
    +++ b/mm/swap_state.c
    @@ -107,11 +107,24 @@ void show_swap_cache_info(void)
    printk("Total swap = %lukB\n", total_swap_pages << (PAGE_SHIFT - 10));
    }

    +void *get_shadow_from_swap_cache(swp_entry_t entry)
    +{
    + struct address_space *address_space = swap_address_space(entry);
    + pgoff_t idx = swp_offset(entry);
    + struct page *page;
    +
    + page = find_get_entry(address_space, idx);
    + if (xa_is_value(page))
    + return page;
    + return NULL;
    +}
    +
    /*
    * add_to_swap_cache resembles add_to_page_cache_locked on swapper_space,
    * but sets SwapCache flag and private instead of mapping and index.
    */
    -int add_to_swap_cache(struct page *page, swp_entry_t entry, gfp_t gfp)
    +int add_to_swap_cache(struct page *page, swp_entry_t entry,
    + gfp_t gfp, void **shadowp)
    {
    struct address_space *address_space = swap_address_space(entry);
    pgoff_t idx = swp_offset(entry);
    @@ -137,8 +150,11 @@ int add_to_swap_cache(struct page *page, swp_entry_t entry, gfp_t gfp)
    for (i = 0; i < nr; i++) {
    VM_BUG_ON_PAGE(xas.xa_index != idx + i, page);
    old = xas_load(&xas);
    - if (xa_is_value(old))
    + if (xa_is_value(old)) {
    nrexceptional++;
    + if (shadowp)
    + *shadowp = old;
    + }
    set_page_private(page + i, entry.val + i);
    xas_store(&xas, page);
    xas_next(&xas);
    @@ -226,7 +242,7 @@ int add_to_swap(struct page *page)
    * Add it to the swap cache.
    */
    err = add_to_swap_cache(page, entry,
    - __GFP_HIGH|__GFP_NOMEMALLOC|__GFP_NOWARN);
    + __GFP_HIGH|__GFP_NOMEMALLOC|__GFP_NOWARN, NULL);
    if (err)
    /*
    * add_to_swap_cache() doesn't return -EEXIST, so we can safely
    @@ -380,6 +396,7 @@ struct page *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
    struct page *found_page = NULL, *new_page = NULL;
    struct swap_info_struct *si;
    int err;
    + void *shadow;
    *new_page_allocated = false;

    do {
    @@ -435,11 +452,15 @@ struct page *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
    /* May fail (-ENOMEM) if XArray node allocation failed. */
    __SetPageLocked(new_page);
    __SetPageSwapBacked(new_page);
    - err = add_to_swap_cache(new_page, entry, gfp_mask & GFP_KERNEL);
    + shadow = NULL;
    + err = add_to_swap_cache(new_page, entry,
    + gfp_mask & GFP_KERNEL, &shadow);
    if (likely(!err)) {
    /* Initiate read into locked page */
    SetPageWorkingset(new_page);
    - lru_cache_add_anon(new_page);
    + if (shadow)
    + workingset_refault(new_page, shadow);
    + lru_cache_add(new_page);
    *new_page_allocated = true;
    return new_page;
    }
    diff --git a/mm/vmscan.c b/mm/vmscan.c
    index 9871861..b37cc26 100644
    --- a/mm/vmscan.c
    +++ b/mm/vmscan.c
    @@ -867,6 +867,7 @@ static int __remove_mapping(struct address_space *mapping, struct page *page,
    {
    unsigned long flags;
    int refcount;
    + void *shadow = NULL;

    BUG_ON(!PageLocked(page));
    BUG_ON(mapping != page_mapping(page));
    @@ -909,12 +910,13 @@ static int __remove_mapping(struct address_space *mapping, struct page *page,
    if (PageSwapCache(page)) {
    swp_entry_t swap = { .val = page_private(page) };
    mem_cgroup_swapout(page, swap);
    - __delete_from_swap_cache(page, swap, NULL);
    + if (reclaimed && !mapping_exiting(mapping))
    + shadow = workingset_eviction(page, target_memcg);
    + __delete_from_swap_cache(page, swap, shadow);
    xa_unlock_irqrestore(&mapping->i_pages, flags);
    put_swap_page(page, swap);
    } else {
    void (*freepage)(struct page *);
    - void *shadow = NULL;

    freepage = mapping->a_ops->freepage;
    /*
    @@ -1476,6 +1478,7 @@ static unsigned long shrink_page_list(struct list_head *page_list,
    SetPageActive(page);
    stat->nr_activate[type] += nr_pages;
    count_memcg_page_event(page, PGACTIVATE);
    + workingset_activation(page);
    }
    keep_locked:
    unlock_page(page);
    --
    2.7.4
    \
     
     \ /
      Last update: 2020-03-17 06:43    [W:4.690 / U:0.388 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site