[06/21] swap: Turn get_swap_page() into folio_alloc_swap()

Message ID	20220429192329.3034378-7-willy@infradead.org (mailing list archive)
State	New
Headers	show Return-Path: <owner-linux-mm@kvack.org> From: "Matthew Wilcox (Oracle)" <willy@infradead.org> To: akpm@linuxfoundation.org Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>, linux-mm@kvack.org Subject: [PATCH 06/21] swap: Turn get_swap_page() into folio_alloc_swap() Date: Fri, 29 Apr 2022 20:23:14 +0100 Message-Id: <20220429192329.3034378-7-willy@infradead.org> In-Reply-To: <20220429192329.3034378-1-willy@infradead.org> References: <20220429192329.3034378-1-willy@infradead.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: owner-linux-mm@kvack.org Precedence: bulk
Series	Folio patches for 5.19 \| expand [00/21] Folio patches for 5.19 [01/21] shmem: Convert shmem_alloc_hugepage() to use vma_alloc_folio() [02/21] mm/huge_memory: Convert do_huge_pmd_anonymous_page() to use vma_alloc_folio() [03/21] mm: Remove alloc_pages_vma() [04/21] vmscan: Use folio_mapped() in shrink_page_list() [05/21] vmscan: Convert the writeback handling in shrink_page_list() to folios [06/21] swap: Turn get_swap_page() into folio_alloc_swap() [07/21] swap: Convert add_to_swap() to take a folio [08/21] vmscan: Convert dirty page handling to folios [09/21] vmscan: Convert page buffer handling to use folios [10/21] vmscan: Convert lazy freeing to folios [11/21] vmscan: Move initialisation of mapping down [12/21] vmscan: Convert the activate_locked portion of shrink_page_list to folios [13/21] vmscan: Remove remaining uses of page in shrink_page_list [14/21] mm/shmem: Use a folio in shmem_unused_huge_shrink [15/21] mm/swap: Add folio_throttle_swaprate [16/21] mm/shmem: Convert shmem_add_to_page_cache to take a folio [17/21] mm/shmem: Turn shmem_should_replace_page into shmem_should_replace_folio [18/21] mm/shmem: Turn shmem_alloc_page() into shmem_alloc_folio() [19/21] mm/shmem: Convert shmem_alloc_and_acct_page to use a folio [20/21] mm/shmem: Convert shmem_getpage_gfp to use a folio [21/21] mm/shmem: Convert shmem_swapin_page() to shmem_swapin_folio()

diff --git a/include/linux/swap.h b/include/linux/swap.h index 27093b477c5f..147a9a173508 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -494,7 +494,7 @@ static inline long get_nr_swap_pages(void) } extern void si_swapinfo(struct sysinfo *); -extern swp_entry_t get_swap_page(struct page *page); +swp_entry_t folio_alloc_swap(struct folio *folio); extern void put_swap_page(struct page *page, swp_entry_t entry); extern swp_entry_t get_swap_page_of_type(int); extern int get_swap_pages(int n, swp_entry_t swp_entries[], int entry_size); @@ -685,7 +685,7 @@ static inline int try_to_free_swap(struct page *page) return 0; } -static inline swp_entry_t get_swap_page(struct page *page) +static inline swp_entry_t folio_alloc_swap(struct folio *folio) { swp_entry_t entry; entry.val = 0; @@ -739,12 +739,13 @@ static inline void cgroup_throttle_swaprate(struct page *page, gfp_t gfp_mask) #ifdef CONFIG_MEMCG_SWAP void mem_cgroup_swapout(struct folio *folio, swp_entry_t entry); -extern int __mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry); -static inline int mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry) +int __mem_cgroup_try_charge_swap(struct folio *folio, swp_entry_t entry); +static inline int mem_cgroup_try_charge_swap(struct folio *folio, + swp_entry_t entry) { if (mem_cgroup_disabled()) return 0; - return __mem_cgroup_try_charge_swap(page, entry); + return __mem_cgroup_try_charge_swap(folio, entry); } extern void __mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_pages); @@ -762,7 +763,7 @@ static inline void mem_cgroup_swapout(struct folio *folio, swp_entry_t entry) { } -static inline int mem_cgroup_try_charge_swap(struct page *page, +static inline int mem_cgroup_try_charge_swap(struct folio *folio, swp_entry_t entry) { return 0; diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 598fece89e2b..985eff804004 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -7125,17 +7125,17 @@ void mem_cgroup_swapout(struct folio *folio, swp_entry_t entry) } /** - * __mem_cgroup_try_charge_swap - try charging swap space for a page - * @page: page being added to swap + * __mem_cgroup_try_charge_swap - try charging swap space for a folio + * @folio: folio being added to swap * @entry: swap entry to charge * - * Try to charge @page's memcg for the swap space at @entry. + * Try to charge @folio's memcg for the swap space at @entry. * * Returns 0 on success, -ENOMEM on failure. */ -int __mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry) +int __mem_cgroup_try_charge_swap(struct folio *folio, swp_entry_t entry) { - unsigned int nr_pages = thp_nr_pages(page); + unsigned int nr_pages = folio_nr_pages(folio); struct page_counter *counter; struct mem_cgroup *memcg; unsigned short oldid; @@ -7143,9 +7143,9 @@ int __mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry) if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) return 0; - memcg = page_memcg(page); + memcg = folio_memcg(folio); - VM_WARN_ON_ONCE_PAGE(!memcg, page); + VM_WARN_ON_ONCE_FOLIO(!memcg, folio); if (!memcg) return 0; @@ -7168,7 +7168,7 @@ int __mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry) if (nr_pages > 1) mem_cgroup_id_get_many(memcg, nr_pages - 1); oldid = swap_cgroup_record(entry, mem_cgroup_id(memcg), nr_pages); - VM_BUG_ON_PAGE(oldid, page); + VM_BUG_ON_FOLIO(oldid, folio); mod_memcg_state(memcg, MEMCG_SWAP, nr_pages); return 0; diff --git a/mm/shmem.c b/mm/shmem.c index c89394221a7e..85c23696efc6 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1312,6 +1312,7 @@ int shmem_unuse(unsigned int type) */ static int shmem_writepage(struct page *page, struct writeback_control *wbc) { + struct folio *folio = page_folio(page); struct shmem_inode_info *info; struct address_space *mapping; struct inode *inode; @@ -1385,7 +1386,7 @@ static int shmem_writepage(struct page *page, struct writeback_control *wbc) SetPageUptodate(page); } - swap = get_swap_page(page); + swap = folio_alloc_swap(folio); if (!swap.val) goto redirty; diff --git a/mm/swap_slots.c b/mm/swap_slots.c index 2b5531840583..0218ec1cd24c 100644 --- a/mm/swap_slots.c +++ b/mm/swap_slots.c @@ -117,7 +117,7 @@ static int alloc_swap_slot_cache(unsigned int cpu) /* * Do allocation outside swap_slots_cache_mutex - * as kvzalloc could trigger reclaim and get_swap_page, + * as kvzalloc could trigger reclaim and folio_alloc_swap, * which can lock swap_slots_cache_mutex. */ slots = kvcalloc(SWAP_SLOTS_CACHE_SIZE, sizeof(swp_entry_t), @@ -213,7 +213,7 @@ static void __drain_swap_slots_cache(unsigned int type) * this function can be invoked in the cpu * hot plug path: * cpu_up -> lock cpu_hotplug -> cpu hotplug state callback - * -> memory allocation -> direct reclaim -> get_swap_page + * -> memory allocation -> direct reclaim -> folio_alloc_swap * -> drain_swap_slots_cache * * Hence the loop over current online cpu below could miss cpu that @@ -301,16 +301,16 @@ int free_swap_slot(swp_entry_t entry) return 0; } -swp_entry_t get_swap_page(struct page *page) +swp_entry_t folio_alloc_swap(struct folio *folio) { swp_entry_t entry; struct swap_slots_cache *cache; entry.val = 0; - if (PageTransHuge(page)) { + if (folio_test_large(folio)) { if (IS_ENABLED(CONFIG_THP_SWAP)) - get_swap_pages(1, &entry, HPAGE_PMD_NR); + get_swap_pages(1, &entry, folio_nr_pages(folio)); goto out; } @@ -344,8 +344,8 @@ swp_entry_t get_swap_page(struct page *page) get_swap_pages(1, &entry, 1); out: - if (mem_cgroup_try_charge_swap(page, entry)) { - put_swap_page(page, entry); + if (mem_cgroup_try_charge_swap(folio, entry)) { + put_swap_page(&folio->page, entry); entry.val = 0; } return entry; diff --git a/mm/swap_state.c b/mm/swap_state.c index 013856004825..989ad18f5468 100644 --- a/mm/swap_state.c +++ b/mm/swap_state.c @@ -183,13 +183,14 @@ void __delete_from_swap_cache(struct page *page, */ int add_to_swap(struct page *page) { + struct folio *folio = page_folio(page); swp_entry_t entry; int err; VM_BUG_ON_PAGE(!PageLocked(page), page); VM_BUG_ON_PAGE(!PageUptodate(page), page); - entry = get_swap_page(page); + entry = folio_alloc_swap(folio); if (!entry.val) return 0; diff --git a/mm/swapfile.c b/mm/swapfile.c index 63c61f8b2611..c34f41553144 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -76,9 +76,9 @@ static PLIST_HEAD(swap_active_head); /* * all available (active, not full) swap_info_structs * protected with swap_avail_lock, ordered by priority. - * This is used by get_swap_page() instead of swap_active_head + * This is used by folio_alloc_swap() instead of swap_active_head * because swap_active_head includes all swap_info_structs, - * but get_swap_page() doesn't need to look at full ones. + * but folio_alloc_swap() doesn't need to look at full ones. * This uses its own lock instead of swap_lock because when a * swap_info_struct changes between not-full/full, it needs to * add/remove itself to/from this list, but the swap_info_struct->lock @@ -2093,11 +2093,12 @@ static int try_to_unuse(unsigned int type) * Under global memory pressure, swap entries can be reinserted back * into process space after the mmlist loop above passes over them. * - * Limit the number of retries? No: when mmget_not_zero() above fails, - * that mm is likely to be freeing swap from exit_mmap(), which proceeds - * at its own independent pace; and even shmem_writepage() could have - * been preempted after get_swap_page(), temporarily hiding that swap. - * It's easy and robust (though cpu-intensive) just to keep retrying. + * Limit the number of retries? No: when mmget_not_zero() + * above fails, that mm is likely to be freeing swap from + * exit_mmap(), which proceeds at its own independent pace; + * and even shmem_writepage() could have been preempted after + * folio_alloc_swap(), temporarily hiding that swap. It's easy + * and robust (though cpu-intensive) just to keep retrying. */ if (READ_ONCE(si->inuse_pages)) { if (!signal_pending(current)) @@ -2310,7 +2311,7 @@ static void _enable_swap_info(struct swap_info_struct *p) * which on removal of any swap_info_struct with an auto-assigned * (i.e. negative) priority increments the auto-assigned priority * of any lower-priority swap_info_structs. - * swap_avail_head needs to be priority ordered for get_swap_page(), + * swap_avail_head needs to be priority ordered for folio_alloc_swap(), * which allocates swap pages from the highest available priority * swap_info_struct. */

[06/21] swap: Turn get_swap_page() into folio_alloc_swap()

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