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-rw-r--r--mm/Kconfig12
-rw-r--r--mm/huge_memory.c11
-rw-r--r--mm/memcontrol.c50
-rw-r--r--mm/shmem.c2
-rw-r--r--mm/swap_cgroup.c40
-rw-r--r--mm/swap_slots.c16
-rw-r--r--mm/swap_state.c114
-rw-r--r--mm/swapfile.c259
8 files changed, 349 insertions, 155 deletions
diff --git a/mm/Kconfig b/mm/Kconfig
index 665cb370ad38..9870baafb096 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -446,6 +446,18 @@ choice
benefit.
endchoice
+config ARCH_WANTS_THP_SWAP
+ def_bool n
+
+config THP_SWAP
+ def_bool y
+ depends on TRANSPARENT_HUGEPAGE && ARCH_WANTS_THP_SWAP
+ help
+ Swap transparent huge pages in one piece, without splitting.
+ XXX: For now this only does clustered swap space allocation.
+
+ For selection by architectures with reasonable THP sizes.
+
config TRANSPARENT_HUGE_PAGECACHE
def_bool y
depends on TRANSPARENT_HUGEPAGE
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index f4d5f9d0f9b7..1a168e4bac4b 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2203,7 +2203,7 @@ static void __split_huge_page_tail(struct page *head, int tail,
* atomic_set() here would be safe on all archs (and not only on x86),
* it's safer to use atomic_inc()/atomic_add().
*/
- if (PageAnon(head)) {
+ if (PageAnon(head) && !PageSwapCache(head)) {
page_ref_inc(page_tail);
} else {
/* Additional pin to radix tree */
@@ -2214,6 +2214,7 @@ static void __split_huge_page_tail(struct page *head, int tail,
page_tail->flags |= (head->flags &
((1L << PG_referenced) |
(1L << PG_swapbacked) |
+ (1L << PG_swapcache) |
(1L << PG_mlocked) |
(1L << PG_uptodate) |
(1L << PG_active) |
@@ -2276,7 +2277,11 @@ static void __split_huge_page(struct page *page, struct list_head *list,
ClearPageCompound(head);
/* See comment in __split_huge_page_tail() */
if (PageAnon(head)) {
- page_ref_inc(head);
+ /* Additional pin to radix tree of swap cache */
+ if (PageSwapCache(head))
+ page_ref_add(head, 2);
+ else
+ page_ref_inc(head);
} else {
/* Additional pin to radix tree */
page_ref_add(head, 2);
@@ -2432,7 +2437,7 @@ int split_huge_page_to_list(struct page *page, struct list_head *list)
ret = -EBUSY;
goto out;
}
- extra_pins = 0;
+ extra_pins = PageSwapCache(page) ? HPAGE_PMD_NR : 0;
mapping = NULL;
anon_vma_lock_write(anon_vma);
} else {
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index d75b38b66ef6..fc51a33ddcd1 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2376,10 +2376,9 @@ void mem_cgroup_split_huge_fixup(struct page *head)
#ifdef CONFIG_MEMCG_SWAP
static void mem_cgroup_swap_statistics(struct mem_cgroup *memcg,
- bool charge)
+ int nr_entries)
{
- int val = (charge) ? 1 : -1;
- this_cpu_add(memcg->stat->count[MEMCG_SWAP], val);
+ this_cpu_add(memcg->stat->count[MEMCG_SWAP], nr_entries);
}
/**
@@ -2405,8 +2404,8 @@ static int mem_cgroup_move_swap_account(swp_entry_t entry,
new_id = mem_cgroup_id(to);
if (swap_cgroup_cmpxchg(entry, old_id, new_id) == old_id) {
- mem_cgroup_swap_statistics(from, false);
- mem_cgroup_swap_statistics(to, true);
+ mem_cgroup_swap_statistics(from, -1);
+ mem_cgroup_swap_statistics(to, 1);
return 0;
}
return -EINVAL;
@@ -5445,7 +5444,7 @@ void mem_cgroup_commit_charge(struct page *page, struct mem_cgroup *memcg,
* let's not wait for it. The page already received a
* memory+swap charge, drop the swap entry duplicate.
*/
- mem_cgroup_uncharge_swap(entry);
+ mem_cgroup_uncharge_swap(entry, nr_pages);
}
}
@@ -5873,9 +5872,9 @@ void mem_cgroup_swapout(struct page *page, swp_entry_t entry)
* ancestor for the swap instead and transfer the memory+swap charge.
*/
swap_memcg = mem_cgroup_id_get_online(memcg);
- oldid = swap_cgroup_record(entry, mem_cgroup_id(swap_memcg));
+ oldid = swap_cgroup_record(entry, mem_cgroup_id(swap_memcg), 1);
VM_BUG_ON_PAGE(oldid, page);
- mem_cgroup_swap_statistics(swap_memcg, true);
+ mem_cgroup_swap_statistics(swap_memcg, 1);
page->mem_cgroup = NULL;
@@ -5902,19 +5901,20 @@ void mem_cgroup_swapout(struct page *page, swp_entry_t entry)
css_put(&memcg->css);
}
-/*
- * mem_cgroup_try_charge_swap - try charging a swap entry
+/**
+ * mem_cgroup_try_charge_swap - try charging swap space for a page
* @page: page being added to swap
* @entry: swap entry to charge
*
- * Try to charge @entry to the memcg that @page belongs to.
+ * Try to charge @page'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)
{
- struct mem_cgroup *memcg;
+ unsigned int nr_pages = hpage_nr_pages(page);
struct page_counter *counter;
+ struct mem_cgroup *memcg;
unsigned short oldid;
if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) || !do_swap_account)
@@ -5929,25 +5929,27 @@ int mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry)
memcg = mem_cgroup_id_get_online(memcg);
if (!mem_cgroup_is_root(memcg) &&
- !page_counter_try_charge(&memcg->swap, 1, &counter)) {
+ !page_counter_try_charge(&memcg->swap, nr_pages, &counter)) {
mem_cgroup_id_put(memcg);
return -ENOMEM;
}
- oldid = swap_cgroup_record(entry, mem_cgroup_id(memcg));
+ /* Get references for the tail pages, too */
+ 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);
- mem_cgroup_swap_statistics(memcg, true);
+ mem_cgroup_swap_statistics(memcg, nr_pages);
return 0;
}
/**
- * mem_cgroup_uncharge_swap - uncharge a swap entry
+ * mem_cgroup_uncharge_swap - uncharge swap space
* @entry: swap entry to uncharge
- *
- * Drop the swap charge associated with @entry.
+ * @nr_pages: the amount of swap space to uncharge
*/
-void mem_cgroup_uncharge_swap(swp_entry_t entry)
+void mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_pages)
{
struct mem_cgroup *memcg;
unsigned short id;
@@ -5955,18 +5957,18 @@ void mem_cgroup_uncharge_swap(swp_entry_t entry)
if (!do_swap_account)
return;
- id = swap_cgroup_record(entry, 0);
+ id = swap_cgroup_record(entry, 0, nr_pages);
rcu_read_lock();
memcg = mem_cgroup_from_id(id);
if (memcg) {
if (!mem_cgroup_is_root(memcg)) {
if (cgroup_subsys_on_dfl(memory_cgrp_subsys))
- page_counter_uncharge(&memcg->swap, 1);
+ page_counter_uncharge(&memcg->swap, nr_pages);
else
- page_counter_uncharge(&memcg->memsw, 1);
+ page_counter_uncharge(&memcg->memsw, nr_pages);
}
- mem_cgroup_swap_statistics(memcg, false);
- mem_cgroup_id_put(memcg);
+ mem_cgroup_swap_statistics(memcg, -nr_pages);
+ mem_cgroup_id_put_many(memcg, nr_pages);
}
rcu_read_unlock();
}
diff --git a/mm/shmem.c b/mm/shmem.c
index 9100c4952698..bbb987c58dad 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1291,7 +1291,7 @@ static int shmem_writepage(struct page *page, struct writeback_control *wbc)
SetPageUptodate(page);
}
- swap = get_swap_page();
+ swap = get_swap_page(page);
if (!swap.val)
goto redirty;
diff --git a/mm/swap_cgroup.c b/mm/swap_cgroup.c
index 3405b4ee1757..fcd2740f4ed7 100644
--- a/mm/swap_cgroup.c
+++ b/mm/swap_cgroup.c
@@ -61,21 +61,27 @@ not_enough_page:
return -ENOMEM;
}
+static struct swap_cgroup *__lookup_swap_cgroup(struct swap_cgroup_ctrl *ctrl,
+ pgoff_t offset)
+{
+ struct page *mappage;
+ struct swap_cgroup *sc;
+
+ mappage = ctrl->map[offset / SC_PER_PAGE];
+ sc = page_address(mappage);
+ return sc + offset % SC_PER_PAGE;
+}
+
static struct swap_cgroup *lookup_swap_cgroup(swp_entry_t ent,
struct swap_cgroup_ctrl **ctrlp)
{
pgoff_t offset = swp_offset(ent);
struct swap_cgroup_ctrl *ctrl;
- struct page *mappage;
- struct swap_cgroup *sc;
ctrl = &swap_cgroup_ctrl[swp_type(ent)];
if (ctrlp)
*ctrlp = ctrl;
-
- mappage = ctrl->map[offset / SC_PER_PAGE];
- sc = page_address(mappage);
- return sc + offset % SC_PER_PAGE;
+ return __lookup_swap_cgroup(ctrl, offset);
}
/**
@@ -108,25 +114,39 @@ unsigned short swap_cgroup_cmpxchg(swp_entry_t ent,
}
/**
- * swap_cgroup_record - record mem_cgroup for this swp_entry.
- * @ent: swap entry to be recorded into
+ * swap_cgroup_record - record mem_cgroup for a set of swap entries
+ * @ent: the first swap entry to be recorded into
* @id: mem_cgroup to be recorded
+ * @nr_ents: number of swap entries to be recorded
*
* Returns old value at success, 0 at failure.
* (Of course, old value can be 0.)
*/
-unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id)
+unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id,
+ unsigned int nr_ents)
{
struct swap_cgroup_ctrl *ctrl;
struct swap_cgroup *sc;
unsigned short old;
unsigned long flags;
+ pgoff_t offset = swp_offset(ent);
+ pgoff_t end = offset + nr_ents;
sc = lookup_swap_cgroup(ent, &ctrl);
spin_lock_irqsave(&ctrl->lock, flags);
old = sc->id;
- sc->id = id;
+ for (;;) {
+ VM_BUG_ON(sc->id != old);
+ sc->id = id;
+ offset++;
+ if (offset == end)
+ break;
+ if (offset % SC_PER_PAGE)
+ sc++;
+ else
+ sc = __lookup_swap_cgroup(ctrl, offset);
+ }
spin_unlock_irqrestore(&ctrl->lock, flags);
return old;
diff --git a/mm/swap_slots.c b/mm/swap_slots.c
index 58f6c78f1dad..90c1032a8ac3 100644
--- a/mm/swap_slots.c
+++ b/mm/swap_slots.c
@@ -263,7 +263,8 @@ static int refill_swap_slots_cache(struct swap_slots_cache *cache)
cache->cur = 0;
if (swap_slot_cache_active)
- cache->nr = get_swap_pages(SWAP_SLOTS_CACHE_SIZE, cache->slots);
+ cache->nr = get_swap_pages(SWAP_SLOTS_CACHE_SIZE, false,
+ cache->slots);
return cache->nr;
}
@@ -301,11 +302,19 @@ direct_free:
return 0;
}
-swp_entry_t get_swap_page(void)
+swp_entry_t get_swap_page(struct page *page)
{
swp_entry_t entry, *pentry;
struct swap_slots_cache *cache;
+ entry.val = 0;
+
+ if (PageTransHuge(page)) {
+ if (IS_ENABLED(CONFIG_THP_SWAP))
+ get_swap_pages(1, true, &entry);
+ return entry;
+ }
+
/*
* Preemption is allowed here, because we may sleep
* in refill_swap_slots_cache(). But it is safe, because
@@ -317,7 +326,6 @@ swp_entry_t get_swap_page(void)
*/
cache = raw_cpu_ptr(&swp_slots);
- entry.val = 0;
if (check_cache_active()) {
mutex_lock(&cache->alloc_lock);
if (cache->slots) {
@@ -337,7 +345,7 @@ repeat:
return entry;
}
- get_swap_pages(1, &entry);
+ get_swap_pages(1, false, &entry);
return entry;
}
diff --git a/mm/swap_state.c b/mm/swap_state.c
index 539b8885e3d1..16ff89d058f4 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -19,6 +19,7 @@
#include <linux/migrate.h>
#include <linux/vmalloc.h>
#include <linux/swap_slots.h>
+#include <linux/huge_mm.h>
#include <asm/pgtable.h>
@@ -38,6 +39,7 @@ struct address_space *swapper_spaces[MAX_SWAPFILES];
static unsigned int nr_swapper_spaces[MAX_SWAPFILES];
#define INC_CACHE_INFO(x) do { swap_cache_info.x++; } while (0)
+#define ADD_CACHE_INFO(x, nr) do { swap_cache_info.x += (nr); } while (0)
static struct {
unsigned long add_total;
@@ -90,39 +92,46 @@ void show_swap_cache_info(void)
*/
int __add_to_swap_cache(struct page *page, swp_entry_t entry)
{
- int error;
+ int error, i, nr = hpage_nr_pages(page);
struct address_space *address_space;
+ pgoff_t idx = swp_offset(entry);
VM_BUG_ON_PAGE(!PageLocked(page), page);
VM_BUG_ON_PAGE(PageSwapCache(page), page);
VM_BUG_ON_PAGE(!PageSwapBacked(page), page);
- get_page(page);
+ page_ref_add(page, nr);
SetPageSwapCache(page);
- set_page_private(page, entry.val);
address_space = swap_address_space(entry);
spin_lock_irq(&address_space->tree_lock);
- error = radix_tree_insert(&address_space->page_tree,
- swp_offset(entry), page);
- if (likely(!error)) {
- address_space->nrpages++;
- __inc_node_page_state(page, NR_FILE_PAGES);
- INC_CACHE_INFO(add_total);
+ for (i = 0; i < nr; i++) {
+ set_page_private(page + i, entry.val + i);
+ error = radix_tree_insert(&address_space->page_tree,
+ idx + i, page + i);
+ if (unlikely(error))
+ break;
}
- spin_unlock_irq(&address_space->tree_lock);
-
- if (unlikely(error)) {
+ if (likely(!error)) {
+ address_space->nrpages += nr;
+ __mod_node_page_state(page_pgdat(page), NR_FILE_PAGES, nr);
+ ADD_CACHE_INFO(add_total, nr);
+ } else {
/*
* Only the context which have set SWAP_HAS_CACHE flag
* would call add_to_swap_cache().
* So add_to_swap_cache() doesn't returns -EEXIST.
*/
VM_BUG_ON(error == -EEXIST);
- set_page_private(page, 0UL);
+ set_page_private(page + i, 0UL);
+ while (i--) {
+ radix_tree_delete(&address_space->page_tree, idx + i);
+ set_page_private(page + i, 0UL);
+ }
ClearPageSwapCache(page);
- put_page(page);
+ page_ref_sub(page, nr);
}
+ spin_unlock_irq(&address_space->tree_lock);
return error;
}
@@ -132,7 +141,7 @@ int add_to_swap_cache(struct page *page, swp_entry_t entry, gfp_t gfp_mask)
{
int error;
- error = radix_tree_maybe_preload(gfp_mask);
+ error = radix_tree_maybe_preload_order(gfp_mask, compound_order(page));
if (!error) {
error = __add_to_swap_cache(page, entry);
radix_tree_preload_end();
@@ -146,8 +155,10 @@ int add_to_swap_cache(struct page *page, swp_entry_t entry, gfp_t gfp_mask)
*/
void __delete_from_swap_cache(struct page *page)
{
- swp_entry_t entry;
struct address_space *address_space;
+ int i, nr = hpage_nr_pages(page);
+ swp_entry_t entry;
+ pgoff_t idx;
VM_BUG_ON_PAGE(!PageLocked(page), page);
VM_BUG_ON_PAGE(!PageSwapCache(page), page);
@@ -155,12 +166,15 @@ void __delete_from_swap_cache(struct page *page)
entry.val = page_private(page);
address_space = swap_address_space(entry);
- radix_tree_delete(&address_space->page_tree, swp_offset(entry));
- set_page_private(page, 0);
+ idx = swp_offset(entry);
+ for (i = 0; i < nr; i++) {
+ radix_tree_delete(&address_space->page_tree, idx + i);
+ set_page_private(page + i, 0);
+ }
ClearPageSwapCache(page);
- address_space->nrpages--;
- __dec_node_page_state(page, NR_FILE_PAGES);
- INC_CACHE_INFO(del_total);
+ address_space->nrpages -= nr;
+ __mod_node_page_state(page_pgdat(page), NR_FILE_PAGES, -nr);
+ ADD_CACHE_INFO(del_total, nr);
}
/**
@@ -178,20 +192,12 @@ int add_to_swap(struct page *page, struct list_head *list)
VM_BUG_ON_PAGE(!PageLocked(page), page);
VM_BUG_ON_PAGE(!PageUptodate(page), page);
- entry = get_swap_page();
+retry:
+ entry = get_swap_page(page);
if (!entry.val)
- return 0;
-
- if (mem_cgroup_try_charge_swap(page, entry)) {
- swapcache_free(entry);
- return 0;
- }
-
- if (unlikely(PageTransHuge(page)))
- if (unlikely(split_huge_page_to_list(page, list))) {
- swapcache_free(entry);
- return 0;
- }
+ goto fail;
+ if (mem_cgroup_try_charge_swap(page, entry))
+ goto fail_free;
/*
* Radix-tree node allocations from PF_MEMALLOC contexts could
@@ -206,17 +212,33 @@ int add_to_swap(struct page *page, struct list_head *list)
*/
err = add_to_swap_cache(page, entry,
__GFP_HIGH|__GFP_NOMEMALLOC|__GFP_NOWARN);
-
- if (!err) {
- return 1;
- } else { /* -ENOMEM radix-tree allocation failure */
+ /* -ENOMEM radix-tree allocation failure */
+ if (err)
/*
* add_to_swap_cache() doesn't return -EEXIST, so we can safely
* clear SWAP_HAS_CACHE flag.
*/
- swapcache_free(entry);
- return 0;
+ goto fail_free;
+
+ if (PageTransHuge(page)) {
+ err = split_huge_page_to_list(page, list);
+ if (err) {
+ delete_from_swap_cache(page);
+ return 0;
+ }
}
+
+ return 1;
+
+fail_free:
+ if (PageTransHuge(page))
+ swapcache_free_cluster(entry);
+ else
+ swapcache_free(entry);
+fail:
+ if (PageTransHuge(page) && !split_huge_page_to_list(page, list))
+ goto retry;
+ return 0;
}
/*
@@ -237,8 +259,12 @@ void delete_from_swap_cache(struct page *page)
__delete_from_swap_cache(page);
spin_unlock_irq(&address_space->tree_lock);
- swapcache_free(entry);
- put_page(page);
+ if (PageTransHuge(page))
+ swapcache_free_cluster(entry);
+ else
+ swapcache_free(entry);
+
+ page_ref_sub(page, hpage_nr_pages(page));
}
/*
@@ -295,7 +321,7 @@ struct page * lookup_swap_cache(swp_entry_t entry)
page = find_get_page(swap_address_space(entry), swp_offset(entry));
- if (page) {
+ if (page && likely(!PageTransCompound(page))) {
INC_CACHE_INFO(find_success);
if (TestClearPageReadahead(page))
atomic_inc(&swapin_readahead_hits);
@@ -506,7 +532,7 @@ struct page *swapin_readahead(swp_entry_t entry, gfp_t gfp_mask,
gfp_mask, vma, addr);
if (!page)
continue;
- if (offset != entry_offset)
+ if (offset != entry_offset && likely(!PageTransCompound(page)))
SetPageReadahead(page);
put_page(page);
}
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 4f6cba1b6632..984f0dd94948 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -199,7 +199,11 @@ static void discard_swap_cluster(struct swap_info_struct *si,
}
}
+#ifdef CONFIG_THP_SWAP
+#define SWAPFILE_CLUSTER HPAGE_PMD_NR
+#else
#define SWAPFILE_CLUSTER 256
+#endif
#define LATENCY_LIMIT 256
static inline void cluster_set_flag(struct swap_cluster_info *info,
@@ -374,6 +378,14 @@ static void swap_cluster_schedule_discard(struct swap_info_struct *si,
schedule_work(&si->discard_work);
}
+static void __free_cluster(struct swap_info_struct *si, unsigned long idx)
+{
+ struct swap_cluster_info *ci = si->cluster_info;
+
+ cluster_set_flag(ci + idx, CLUSTER_FLAG_FREE);
+ cluster_list_add_tail(&si->free_clusters, ci, idx);
+}
+
/*
* Doing discard actually. After a cluster discard is finished, the cluster
* will be added to free cluster list. caller should hold si->lock.
@@ -394,10 +406,7 @@ static void swap_do_scheduled_discard(struct swap_info_struct *si)
spin_lock(&si->lock);
ci = lock_cluster(si, idx * SWAPFILE_CLUSTER);
- cluster_set_flag(ci, CLUSTER_FLAG_FREE);
- unlock_cluster(ci);
- cluster_list_add_tail(&si->free_clusters, info, idx);
- ci = lock_cluster(si, idx * SWAPFILE_CLUSTER);
+ __free_cluster(si, idx);
memset(si->swap_map + idx * SWAPFILE_CLUSTER,
0, SWAPFILE_CLUSTER);
unlock_cluster(ci);
@@ -415,6 +424,34 @@ static void swap_discard_work(struct work_struct *work)
spin_unlock(&si->lock);
}
+static void alloc_cluster(struct swap_info_struct *si, unsigned long idx)
+{
+ struct swap_cluster_info *ci = si->cluster_info;
+
+ VM_BUG_ON(cluster_list_first(&si->free_clusters) != idx);
+ cluster_list_del_first(&si->free_clusters, ci);
+ cluster_set_count_flag(ci + idx, 0, 0);
+}
+
+static void free_cluster(struct swap_info_struct *si, unsigned long idx)
+{
+ struct swap_cluster_info *ci = si->cluster_info + idx;
+
+ VM_BUG_ON(cluster_count(ci) != 0);
+ /*
+ * If the swap is discardable, prepare discard the cluster
+ * instead of free it immediately. The cluster will be freed
+ * after discard.
+ */
+ if ((si->flags & (SWP_WRITEOK | SWP_PAGE_DISCARD)) ==
+ (SWP_WRITEOK | SWP_PAGE_DISCARD)) {
+ swap_cluster_schedule_discard(si, idx);
+ return;
+ }
+
+ __free_cluster(si, idx);
+}
+
/*
* The cluster corresponding to page_nr will be used. The cluster will be
* removed from free cluster list and its usage counter will be increased.
@@ -426,11 +463,8 @@ static void inc_cluster_info_page(struct swap_info_struct *p,
if (!cluster_info)
return;
- if (cluster_is_free(&cluster_info[idx])) {
- VM_BUG_ON(cluster_list_first(&p->free_clusters) != idx);
- cluster_list_del_first(&p->free_clusters, cluster_info);
- cluster_set_count_flag(&cluster_info[idx], 0, 0);
- }
+ if (cluster_is_free(&cluster_info[idx]))
+ alloc_cluster(p, idx);
VM_BUG_ON(cluster_count(&cluster_info[idx]) >= SWAPFILE_CLUSTER);
cluster_set_count(&cluster_info[idx],
@@ -454,21 +488,8 @@ static void dec_cluster_info_page(struct swap_info_struct *p,
cluster_set_count(&cluster_info[idx],
cluster_count(&cluster_info[idx]) - 1);
- if (cluster_count(&cluster_info[idx]) == 0) {
- /*
- * If the swap is discardable, prepare discard the cluster
- * instead of free it immediately. The cluster will be freed
- * after discard.
- */
- if ((p->flags & (SWP_WRITEOK | SWP_PAGE_DISCARD)) ==
- (SWP_WRITEOK | SWP_PAGE_DISCARD)) {
- swap_cluster_schedule_discard(p, idx);
- return;
- }
-
- cluster_set_flag(&cluster_info[idx], CLUSTER_FLAG_FREE);
- cluster_list_add_tail(&p->free_clusters, cluster_info, idx);
- }
+ if (cluster_count(&cluster_info[idx]) == 0)
+ free_cluster(p, idx);
}
/*
@@ -558,6 +579,60 @@ new_cluster:
return found_free;
}
+static void swap_range_alloc(struct swap_info_struct *si, unsigned long offset,
+ unsigned int nr_entries)
+{
+ unsigned int end = offset + nr_entries - 1;
+
+ if (offset == si->lowest_bit)
+ si->lowest_bit += nr_entries;
+ if (end == si->highest_bit)
+ si->highest_bit -= nr_entries;
+ si->inuse_pages += nr_entries;
+ if (si->inuse_pages == si->pages) {
+ si->lowest_bit = si->max;
+ si->highest_bit = 0;
+ spin_lock(&swap_avail_lock);
+ plist_del(&si->avail_list, &swap_avail_head);
+ spin_unlock(&swap_avail_lock);
+ }
+}
+
+static void swap_range_free(struct swap_info_struct *si, unsigned long offset,
+ unsigned int nr_entries)
+{
+ unsigned long end = offset + nr_entries - 1;
+ void (*swap_slot_free_notify)(struct block_device *, unsigned long);
+
+ if (offset < si->lowest_bit)
+ si->lowest_bit = offset;
+ if (end > si->highest_bit) {
+ bool was_full = !si->highest_bit;
+
+ si->highest_bit = end;
+ if (was_full && (si->flags & SWP_WRITEOK)) {
+ spin_lock(&swap_avail_lock);
+ WARN_ON(!plist_node_empty(&si->avail_list));
+ if (plist_node_empty(&si->avail_list))
+ plist_add(&si->avail_list, &swap_avail_head);
+ spin_unlock(&swap_avail_lock);
+ }
+ }
+ atomic_long_add(nr_entries, &nr_swap_pages);
+ si->inuse_pages -= nr_entries;
+ if (si->flags & SWP_BLKDEV)
+ swap_slot_free_notify =
+ si->bdev->bd_disk->fops->swap_slot_free_notify;
+ else
+ swap_slot_free_notify = NULL;
+ while (offset <= end) {
+ frontswap_invalidate_page(si->type, offset);
+ if (swap_slot_free_notify)
+ swap_slot_free_notify(si->bdev, offset);
+ offset++;
+ }
+}
+
static int scan_swap_map_slots(struct swap_info_struct *si,
unsigned char usage, int nr,
swp_entry_t slots[])
@@ -676,18 +751,7 @@ checks:
inc_cluster_info_page(si, si->cluster_info, offset);
unlock_cluster(ci);
- if (offset == si->lowest_bit)
- si->lowest_bit++;
- if (offset == si->highest_bit)
- si->highest_bit--;
- si->inuse_pages++;
- if (si->inuse_pages == si->pages) {
- si->lowest_bit = si->max;
- si->highest_bit = 0;
- spin_lock(&swap_avail_lock);
- plist_del(&si->avail_list, &swap_avail_head);
- spin_unlock(&swap_avail_lock);
- }
+ swap_range_alloc(si, offset, 1);
si->cluster_next = offset + 1;
slots[n_ret++] = swp_entry(si->type, offset);
@@ -766,6 +830,52 @@ no_page:
return n_ret;
}
+#ifdef CONFIG_THP_SWAP
+static int swap_alloc_cluster(struct swap_info_struct *si, swp_entry_t *slot)
+{
+ unsigned long idx;
+ struct swap_cluster_info *ci;
+ unsigned long offset, i;
+ unsigned char *map;
+
+ if (cluster_list_empty(&si->free_clusters))
+ return 0;
+
+ idx = cluster_list_first(&si->free_clusters);
+ offset = idx * SWAPFILE_CLUSTER;
+ ci = lock_cluster(si, offset);
+ alloc_cluster(si, idx);
+ cluster_set_count_flag(ci, SWAPFILE_CLUSTER, 0);
+
+ map = si->swap_map + offset;
+ for (i = 0; i < SWAPFILE_CLUSTER; i++)
+ map[i] = SWAP_HAS_CACHE;
+ unlock_cluster(ci);
+ swap_range_alloc(si, offset, SWAPFILE_CLUSTER);
+ *slot = swp_entry(si->type, offset);
+
+ return 1;
+}
+
+static void swap_free_cluster(struct swap_info_struct *si, unsigned long idx)
+{
+ unsigned long offset = idx * SWAPFILE_CLUSTER;
+ struct swap_cluster_info *ci;
+
+ ci = lock_cluster(si, offset);
+ cluster_set_count_flag(ci, 0, 0);
+ free_cluster(si, idx);
+ unlock_cluster(ci);
+ swap_range_free(si, offset, SWAPFILE_CLUSTER);
+}
+#else
+static int swap_alloc_cluster(struct swap_info_struct *si, swp_entry_t *slot)
+{
+ VM_WARN_ON_ONCE(1);
+ return 0;
+}
+#endif /* CONFIG_THP_SWAP */
+
static unsigned long scan_swap_map(struct swap_info_struct *si,
unsigned char usage)
{
@@ -781,13 +891,17 @@ static unsigned long scan_swap_map(struct swap_info_struct *si,
}
-int get_swap_pages(int n_goal, swp_entry_t swp_entries[])
+int get_swap_pages(int n_goal, bool cluster, swp_entry_t swp_entries[])
{
+ unsigned long nr_pages = cluster ? SWAPFILE_CLUSTER : 1;
struct swap_info_struct *si, *next;
long avail_pgs;
int n_ret = 0;
- avail_pgs = atomic_long_read(&nr_swap_pages);
+ /* Only single cluster request supported */
+ WARN_ON_ONCE(n_goal > 1 && cluster);
+
+ avail_pgs = atomic_long_read(&nr_swap_pages) / nr_pages;
if (avail_pgs <= 0)
goto noswap;
@@ -797,7 +911,7 @@ int get_swap_pages(int n_goal, swp_entry_t swp_entries[])
if (n_goal > avail_pgs)
n_goal = avail_pgs;
- atomic_long_sub(n_goal, &nr_swap_pages);
+ atomic_long_sub(n_goal * nr_pages, &nr_swap_pages);
spin_lock(&swap_avail_lock);
@@ -823,10 +937,13 @@ start_over:
spin_unlock(&si->lock);
goto nextsi;
}
- n_ret = scan_swap_map_slots(si, SWAP_HAS_CACHE,
- n_goal, swp_entries);
+ if (cluster)
+ n_ret = swap_alloc_cluster(si, swp_entries);
+ else
+ n_ret = scan_swap_map_slots(si, SWAP_HAS_CACHE,
+ n_goal, swp_entries);
spin_unlock(&si->lock);
- if (n_ret)
+ if (n_ret || cluster)
goto check_out;
pr_debug("scan_swap_map of si %d failed to find offset\n",
si->type);
@@ -852,7 +969,8 @@ nextsi:
check_out:
if (n_ret < n_goal)
- atomic_long_add((long) (n_goal-n_ret), &nr_swap_pages);
+ atomic_long_add((long)(n_goal - n_ret) * nr_pages,
+ &nr_swap_pages);
noswap:
return n_ret;
}
@@ -1008,32 +1126,8 @@ static void swap_entry_free(struct swap_info_struct *p, swp_entry_t entry)
dec_cluster_info_page(p, p->cluster_info, offset);
unlock_cluster(ci);
- mem_cgroup_uncharge_swap(entry);
- if (offset < p->lowest_bit)
- p->lowest_bit = offset;
- if (offset > p->highest_bit) {
- bool was_full = !p->highest_bit;
-
- p->highest_bit = offset;
- if (was_full && (p->flags & SWP_WRITEOK)) {
- spin_lock(&swap_avail_lock);
- WARN_ON(!plist_node_empty(&p->avail_list));
- if (plist_node_empty(&p->avail_list))
- plist_add(&p->avail_list,
- &swap_avail_head);
- spin_unlock(&swap_avail_lock);
- }
- }
- atomic_long_inc(&nr_swap_pages);
- p->inuse_pages--;
- frontswap_invalidate_page(p->type, offset);
- if (p->flags & SWP_BLKDEV) {
- struct gendisk *disk = p->bdev->bd_disk;
-
- if (disk->fops->swap_slot_free_notify)
- disk->fops->swap_slot_free_notify(p->bdev,
- offset);
- }
+ mem_cgroup_uncharge_swap(entry, 1);
+ swap_range_free(p, offset, 1);
}
/*
@@ -1065,6 +1159,33 @@ void swapcache_free(swp_entry_t entry)
}
}
+#ifdef CONFIG_THP_SWAP
+void swapcache_free_cluster(swp_entry_t entry)
+{
+ unsigned long offset = swp_offset(entry);
+ unsigned long idx = offset / SWAPFILE_CLUSTER;
+ struct swap_cluster_info *ci;
+ struct swap_info_struct *si;
+ unsigned char *map;
+ unsigned int i;
+
+ si = swap_info_get(entry);
+ if (!si)
+ return;
+
+ ci = lock_cluster(si, offset);
+ map = si->swap_map + offset;
+ for (i = 0; i < SWAPFILE_CLUSTER; i++) {
+ VM_BUG_ON(map[i] != SWAP_HAS_CACHE);
+ map[i] = 0;
+ }
+ unlock_cluster(ci);
+ mem_cgroup_uncharge_swap(entry, SWAPFILE_CLUSTER);
+ swap_free_cluster(si, idx);
+ spin_unlock(&si->lock);
+}
+#endif /* CONFIG_THP_SWAP */
+
void swapcache_free_entries(swp_entry_t *entries, int n)
{
struct swap_info_struct *p, *prev;
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-15 15:38:13 +0100