diff --git a/include/linux/swap.h b/include/linux/swap.h index 61d63379e956..9c4ae6f14eea 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -400,16 +400,17 @@ extern struct page *do_swap_page_readahead(swp_entry_t fentry, gfp_t gfp_mask, struct vm_fault *vmf, struct vma_swap_readahead *swap_ra); -static inline bool swap_use_vma_readahead(void) -{ - return READ_ONCE(swap_vma_readahead); -} - /* linux/mm/swapfile.c */ extern atomic_long_t nr_swap_pages; extern long total_swap_pages; +extern atomic_t nr_rotate_swap; extern bool has_usable_swap(void); +static inline bool swap_use_vma_readahead(void) +{ + return READ_ONCE(swap_vma_readahead) && !atomic_read(&nr_rotate_swap); +} + /* Swap 50% full? Release swapcache more aggressively.. */ static inline bool vm_swap_full(void) { diff --git a/mm/swapfile.c b/mm/swapfile.c index 42eff9e4e972..4f8b3e08a547 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -96,6 +96,8 @@ static DECLARE_WAIT_QUEUE_HEAD(proc_poll_wait); /* Activity counter to indicate that a swapon or swapoff has occurred */ static atomic_t proc_poll_event = ATOMIC_INIT(0); +atomic_t nr_rotate_swap = ATOMIC_INIT(0); + static inline unsigned char swap_count(unsigned char ent) { return ent & ~SWAP_HAS_CACHE; /* may include SWAP_HAS_CONT flag */ @@ -2569,6 +2571,9 @@ SYSCALL_DEFINE1(swapoff, const char __user *, specialfile) if (p->flags & SWP_CONTINUED) free_swap_count_continuations(p); + if (!p->bdev || !blk_queue_nonrot(bdev_get_queue(p->bdev))) + atomic_dec(&nr_rotate_swap); + mutex_lock(&swapon_mutex); spin_lock(&swap_lock); spin_lock(&p->lock); @@ -3145,7 +3150,8 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags) cluster = per_cpu_ptr(p->percpu_cluster, cpu); cluster_set_null(&cluster->index); } - } + } else + atomic_inc(&nr_rotate_swap); error = swap_cgroup_swapon(p->type, maxpages); if (error)