diff options
Diffstat (limited to 'mm/swap_state.c')
| -rw-r--r-- | mm/swap_state.c | 48 |
1 files changed, 37 insertions, 11 deletions
diff --git a/mm/swap_state.c b/mm/swap_state.c index db5da2baafb1..b97da97b6846 100644 --- a/mm/swap_state.c +++ b/mm/swap_state.c @@ -38,7 +38,7 @@ static const struct address_space_operations swap_aops = { struct address_space *swapper_spaces[MAX_SWAPFILES] __read_mostly; static unsigned int nr_swapper_spaces[MAX_SWAPFILES] __read_mostly; -bool swap_vma_readahead __read_mostly = true; +bool enable_vma_readahead __read_mostly = true; #define SWAP_RA_WIN_SHIFT (PAGE_SHIFT / 2) #define SWAP_RA_HITS_MASK ((1UL << SWAP_RA_WIN_SHIFT) - 1) @@ -322,6 +322,11 @@ void free_pages_and_swap_cache(struct page **pages, int nr) release_pages(pagep, nr); } +static inline bool swap_use_vma_readahead(void) +{ + return READ_ONCE(enable_vma_readahead) && !atomic_read(&nr_rotate_swap); +} + /* * Lookup a swap entry in the swap cache. A found page will be returned * unlocked and with its refcount incremented - we rely on the kernel @@ -544,11 +549,10 @@ static unsigned long swapin_nr_pages(unsigned long offset) } /** - * swapin_readahead - swap in pages in hope we need them soon + * swap_cluster_readahead - swap in pages in hope we need them soon * @entry: swap entry of this memory * @gfp_mask: memory allocation flags - * @vma: user vma this address belongs to - * @addr: target address for mempolicy + * @vmf: fault information * * Returns the struct page for entry and addr, after queueing swapin. * @@ -560,10 +564,10 @@ static unsigned long swapin_nr_pages(unsigned long offset) * This has been extended to use the NUMA policies from the mm triggering * the readahead. * - * Caller must hold down_read on the vma->vm_mm if vma is not NULL. + * Caller must hold down_read on the vma->vm_mm if vmf->vma is not NULL. */ -struct page *swapin_readahead(swp_entry_t entry, gfp_t gfp_mask, - struct vm_area_struct *vma, unsigned long addr) +struct page *swap_cluster_readahead(swp_entry_t entry, gfp_t gfp_mask, + struct vm_fault *vmf) { struct page *page; unsigned long entry_offset = swp_offset(entry); @@ -573,6 +577,8 @@ struct page *swapin_readahead(swp_entry_t entry, gfp_t gfp_mask, struct swap_info_struct *si = swp_swap_info(entry); struct blk_plug plug; bool do_poll = true, page_allocated; + struct vm_area_struct *vma = vmf->vma; + unsigned long addr = vmf->address; mask = swapin_nr_pages(offset) - 1; if (!mask) @@ -727,7 +733,7 @@ static void swap_ra_info(struct vm_fault *vmf, pte_unmap(orig_pte); } -struct page *do_swap_page_readahead(swp_entry_t fentry, gfp_t gfp_mask, +struct page *swap_vma_readahead(swp_entry_t fentry, gfp_t gfp_mask, struct vm_fault *vmf) { struct blk_plug plug; @@ -774,20 +780,40 @@ skip: ra_info.win == 1); } +/** + * swapin_readahead - swap in pages in hope we need them soon + * @entry: swap entry of this memory + * @gfp_mask: memory allocation flags + * @vmf: fault information + * + * Returns the struct page for entry and addr, after queueing swapin. + * + * It's a main entry function for swap readahead. By the configuration, + * it will read ahead blocks by cluster-based(ie, physical disk based) + * or vma-based(ie, virtual address based on faulty address) readahead. + */ +struct page *swapin_readahead(swp_entry_t entry, gfp_t gfp_mask, + struct vm_fault *vmf) +{ + return swap_use_vma_readahead() ? + swap_vma_readahead(entry, gfp_mask, vmf) : + swap_cluster_readahead(entry, gfp_mask, vmf); +} + #ifdef CONFIG_SYSFS static ssize_t vma_ra_enabled_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { - return sprintf(buf, "%s\n", swap_vma_readahead ? "true" : "false"); + return sprintf(buf, "%s\n", enable_vma_readahead ? "true" : "false"); } static ssize_t vma_ra_enabled_store(struct kobject *kobj, struct kobj_attribute *attr, const char *buf, size_t count) { if (!strncmp(buf, "true", 4) || !strncmp(buf, "1", 1)) - swap_vma_readahead = true; + enable_vma_readahead = true; else if (!strncmp(buf, "false", 5) || !strncmp(buf, "0", 1)) - swap_vma_readahead = false; + enable_vma_readahead = false; else return -EINVAL; |