diff options
| -rw-r--r-- | mm/swap.h | 6 | ||||
| -rw-r--r-- | mm/swap_state.c | 46 | ||||
| -rw-r--r-- | mm/swapfile.c | 2 | ||||
| -rw-r--r-- | mm/zswap.c | 4 |
4 files changed, 39 insertions, 19 deletions
diff --git a/mm/swap.h b/mm/swap.h index 709613a4988d..9f8f09fb2644 100644 --- a/mm/swap.h +++ b/mm/swap.h @@ -249,6 +249,9 @@ struct folio *swap_cache_get_folio(swp_entry_t entry); void *swap_cache_get_shadow(swp_entry_t entry); void swap_cache_add_folio(struct folio *folio, swp_entry_t entry, void **shadow); void swap_cache_del_folio(struct folio *folio); +struct folio *swap_cache_alloc_folio(swp_entry_t entry, gfp_t gfp_flags, + struct mempolicy *mpol, pgoff_t ilx, + bool *alloced, bool skip_if_exists); /* Below helpers require the caller to lock and pass in the swap cluster. */ void __swap_cache_del_folio(struct swap_cluster_info *ci, struct folio *folio, swp_entry_t entry, void *shadow); @@ -261,9 +264,6 @@ void swapcache_clear(struct swap_info_struct *si, swp_entry_t entry, int nr); struct folio *read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask, struct vm_area_struct *vma, unsigned long addr, struct swap_iocb **plug); -struct folio *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_flags, - struct mempolicy *mpol, pgoff_t ilx, bool *new_page_allocated, - bool skip_if_exists); struct folio *swap_cluster_readahead(swp_entry_t entry, gfp_t flag, struct mempolicy *mpol, pgoff_t ilx); struct folio *swapin_readahead(swp_entry_t entry, gfp_t flag, diff --git a/mm/swap_state.c b/mm/swap_state.c index 869f6935c20d..89f04f147b02 100644 --- a/mm/swap_state.c +++ b/mm/swap_state.c @@ -401,9 +401,29 @@ void swap_update_readahead(struct folio *folio, struct vm_area_struct *vma, } } -struct folio *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask, - struct mempolicy *mpol, pgoff_t ilx, bool *new_page_allocated, - bool skip_if_exists) +/** + * swap_cache_alloc_folio - Allocate folio for swapped out slot in swap cache. + * @entry: the swapped out swap entry to be binded to the folio. + * @gfp_mask: memory allocation flags + * @mpol: NUMA memory allocation policy to be applied + * @ilx: NUMA interleave index, for use only when MPOL_INTERLEAVE + * @new_page_allocated: sets true if allocation happened, false otherwise + * @skip_if_exists: if the slot is a partially cached state, return NULL. + * This is a workaround that would be removed shortly. + * + * Allocate a folio in the swap cache for one swap slot, typically before + * doing IO (e.g. swap in or zswap writeback). The swap slot indicated by + * @entry must have a non-zero swap count (swapped out). + * Currently only supports order 0. + * + * Context: Caller must protect the swap device with reference count or locks. + * Return: Returns the existing folio if @entry is cached already. Returns + * NULL if failed due to -ENOMEM or @entry have a swap count < 1. + */ +struct folio *swap_cache_alloc_folio(swp_entry_t entry, gfp_t gfp_mask, + struct mempolicy *mpol, pgoff_t ilx, + bool *new_page_allocated, + bool skip_if_exists) { struct swap_info_struct *si = __swap_entry_to_info(entry); struct folio *folio; @@ -451,12 +471,12 @@ struct folio *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask, goto put_and_return; /* - * Protect against a recursive call to __read_swap_cache_async() + * Protect against a recursive call to swap_cache_alloc_folio() * on the same entry waiting forever here because SWAP_HAS_CACHE * is set but the folio is not the swap cache yet. This can * happen today if mem_cgroup_swapin_charge_folio() below * triggers reclaim through zswap, which may call - * __read_swap_cache_async() in the writeback path. + * swap_cache_alloc_folio() in the writeback path. */ if (skip_if_exists) goto put_and_return; @@ -465,7 +485,7 @@ struct folio *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask, * We might race against __swap_cache_del_folio(), and * stumble across a swap_map entry whose SWAP_HAS_CACHE * has not yet been cleared. Or race against another - * __read_swap_cache_async(), which has set SWAP_HAS_CACHE + * swap_cache_alloc_folio(), which has set SWAP_HAS_CACHE * in swap_map, but not yet added its folio to swap cache. */ schedule_timeout_uninterruptible(1); @@ -524,7 +544,7 @@ struct folio *read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask, return NULL; mpol = get_vma_policy(vma, addr, 0, &ilx); - folio = __read_swap_cache_async(entry, gfp_mask, mpol, ilx, + folio = swap_cache_alloc_folio(entry, gfp_mask, mpol, ilx, &page_allocated, false); mpol_cond_put(mpol); @@ -642,9 +662,9 @@ struct folio *swap_cluster_readahead(swp_entry_t entry, gfp_t gfp_mask, blk_start_plug(&plug); for (offset = start_offset; offset <= end_offset ; offset++) { /* Ok, do the async read-ahead now */ - folio = __read_swap_cache_async( - swp_entry(swp_type(entry), offset), - gfp_mask, mpol, ilx, &page_allocated, false); + folio = swap_cache_alloc_folio( + swp_entry(swp_type(entry), offset), gfp_mask, mpol, ilx, + &page_allocated, false); if (!folio) continue; if (page_allocated) { @@ -661,7 +681,7 @@ struct folio *swap_cluster_readahead(swp_entry_t entry, gfp_t gfp_mask, lru_add_drain(); /* Push any new pages onto the LRU now */ skip: /* The page was likely read above, so no need for plugging here */ - folio = __read_swap_cache_async(entry, gfp_mask, mpol, ilx, + folio = swap_cache_alloc_folio(entry, gfp_mask, mpol, ilx, &page_allocated, false); if (unlikely(page_allocated)) swap_read_folio(folio, NULL); @@ -766,7 +786,7 @@ static struct folio *swap_vma_readahead(swp_entry_t targ_entry, gfp_t gfp_mask, if (!si) continue; } - folio = __read_swap_cache_async(entry, gfp_mask, mpol, ilx, + folio = swap_cache_alloc_folio(entry, gfp_mask, mpol, ilx, &page_allocated, false); if (si) put_swap_device(si); @@ -788,7 +808,7 @@ static struct folio *swap_vma_readahead(swp_entry_t targ_entry, gfp_t gfp_mask, lru_add_drain(); skip: /* The folio was likely read above, so no need for plugging here */ - folio = __read_swap_cache_async(targ_entry, gfp_mask, mpol, targ_ilx, + folio = swap_cache_alloc_folio(targ_entry, gfp_mask, mpol, targ_ilx, &page_allocated, false); if (unlikely(page_allocated)) swap_read_folio(folio, NULL); diff --git a/mm/swapfile.c b/mm/swapfile.c index 76273ad26739..5cfa068fd7c9 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -1574,7 +1574,7 @@ static unsigned char swap_entry_put_locked(struct swap_info_struct *si, * CPU1 CPU2 * do_swap_page() * ... swapoff+swapon - * __read_swap_cache_async() + * swap_cache_alloc_folio() * swapcache_prepare() * __swap_duplicate() * // check swap_map diff --git a/mm/zswap.c b/mm/zswap.c index 1f6c007310d8..3e99215915c5 100644 --- a/mm/zswap.c +++ b/mm/zswap.c @@ -1013,8 +1013,8 @@ static int zswap_writeback_entry(struct zswap_entry *entry, return -EEXIST; mpol = get_task_policy(current); - folio = __read_swap_cache_async(swpentry, GFP_KERNEL, mpol, - NO_INTERLEAVE_INDEX, &folio_was_allocated, true); + folio = swap_cache_alloc_folio(swpentry, GFP_KERNEL, mpol, + NO_INTERLEAVE_INDEX, &folio_was_allocated, true); put_swap_device(si); if (!folio) return -ENOMEM; |