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-rw-r--r--mm/Kconfig25
-rw-r--r--mm/Makefile1
-rw-r--r--mm/compaction.c20
-rw-r--r--mm/filemap.c4
-rw-r--r--mm/huge_memory.c20
-rw-r--r--mm/ksm.c2
-rw-r--r--mm/memcontrol.c27
-rw-r--r--mm/memory-failure.c8
-rw-r--r--mm/memory.c15
-rw-r--r--mm/mempolicy.c2
-rw-r--r--mm/migrate.c11
-rw-r--r--mm/mprotect.c25
-rw-r--r--mm/oom_kill.c2
-rw-r--r--mm/page-writeback.c5
-rw-r--r--mm/page_alloc.c30
-rw-r--r--mm/slab.c2
-rw-r--r--mm/slub.c93
-rw-r--r--mm/swap.c4
-rw-r--r--mm/swap_state.c63
-rw-r--r--mm/swapfile.c11
-rw-r--r--mm/vmpressure.c1
-rw-r--r--mm/vmstat.c4
-rw-r--r--mm/zsmalloc.c1106
23 files changed, 1367 insertions, 114 deletions
diff --git a/mm/Kconfig b/mm/Kconfig
index 723bbe04a0b0..2888024e0b0a 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -552,3 +552,28 @@ config MEM_SOFT_DIRTY
it can be cleared by hands.
See Documentation/vm/soft-dirty.txt for more details.
+
+config ZSMALLOC
+ bool "Memory allocator for compressed pages"
+ depends on MMU
+ default n
+ help
+ zsmalloc is a slab-based memory allocator designed to store
+ compressed RAM pages. zsmalloc uses virtual memory mapping
+ in order to reduce fragmentation. However, this results in a
+ non-standard allocator interface where a handle, not a pointer, is
+ returned by an alloc(). This handle must be mapped in order to
+ access the allocated space.
+
+config PGTABLE_MAPPING
+ bool "Use page table mapping to access object in zsmalloc"
+ depends on ZSMALLOC
+ help
+ By default, zsmalloc uses a copy-based object mapping method to
+ access allocations that span two pages. However, if a particular
+ architecture (ex, ARM) performs VM mapping faster than copying,
+ then you should select this. This causes zsmalloc to use page table
+ mapping rather than copying for object mapping.
+
+ You can check speed with zsmalloc benchmark:
+ https://github.com/spartacus06/zsmapbench
diff --git a/mm/Makefile b/mm/Makefile
index 305d10acd081..310c90a09264 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -60,3 +60,4 @@ obj-$(CONFIG_DEBUG_KMEMLEAK_TEST) += kmemleak-test.o
obj-$(CONFIG_CLEANCACHE) += cleancache.o
obj-$(CONFIG_MEMORY_ISOLATION) += page_isolation.o
obj-$(CONFIG_ZBUD) += zbud.o
+obj-$(CONFIG_ZSMALLOC) += zsmalloc.o
diff --git a/mm/compaction.c b/mm/compaction.c
index b48c5259ea33..918577595ea8 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -251,7 +251,6 @@ static unsigned long isolate_freepages_block(struct compact_control *cc,
{
int nr_scanned = 0, total_isolated = 0;
struct page *cursor, *valid_page = NULL;
- unsigned long nr_strict_required = end_pfn - blockpfn;
unsigned long flags;
bool locked = false;
@@ -264,11 +263,12 @@ static unsigned long isolate_freepages_block(struct compact_control *cc,
nr_scanned++;
if (!pfn_valid_within(blockpfn))
- continue;
+ goto isolate_fail;
+
if (!valid_page)
valid_page = page;
if (!PageBuddy(page))
- continue;
+ goto isolate_fail;
/*
* The zone lock must be held to isolate freepages.
@@ -289,12 +289,10 @@ static unsigned long isolate_freepages_block(struct compact_control *cc,
/* Recheck this is a buddy page under lock */
if (!PageBuddy(page))
- continue;
+ goto isolate_fail;
/* Found a free page, break it into order-0 pages */
isolated = split_free_page(page);
- if (!isolated && strict)
- break;
total_isolated += isolated;
for (i = 0; i < isolated; i++) {
list_add(&page->lru, freelist);
@@ -305,7 +303,15 @@ static unsigned long isolate_freepages_block(struct compact_control *cc,
if (isolated) {
blockpfn += isolated - 1;
cursor += isolated - 1;
+ continue;
}
+
+isolate_fail:
+ if (strict)
+ break;
+ else
+ continue;
+
}
trace_mm_compaction_isolate_freepages(nr_scanned, total_isolated);
@@ -315,7 +321,7 @@ static unsigned long isolate_freepages_block(struct compact_control *cc,
* pages requested were isolated. If there were any failures, 0 is
* returned and CMA will fail.
*/
- if (strict && nr_strict_required > total_isolated)
+ if (strict && blockpfn < end_pfn)
total_isolated = 0;
if (locked)
diff --git a/mm/filemap.c b/mm/filemap.c
index d56d3c145b9f..7a13f6ac5421 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2553,8 +2553,8 @@ ssize_t generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
if (ret > 0) {
ssize_t err;
- err = generic_write_sync(file, pos, ret);
- if (err < 0 && ret > 0)
+ err = generic_write_sync(file, iocb->ki_pos - ret, ret);
+ if (err < 0)
ret = err;
}
return ret;
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 82166bf974e1..1546655a2d78 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1166,8 +1166,10 @@ alloc:
} else {
ret = do_huge_pmd_wp_page_fallback(mm, vma, address,
pmd, orig_pmd, page, haddr);
- if (ret & VM_FAULT_OOM)
+ if (ret & VM_FAULT_OOM) {
split_huge_page(page);
+ ret |= VM_FAULT_FALLBACK;
+ }
put_page(page);
}
count_vm_event(THP_FAULT_FALLBACK);
@@ -1179,9 +1181,10 @@ alloc:
if (page) {
split_huge_page(page);
put_page(page);
- }
+ } else
+ split_huge_page_pmd(vma, address, pmd);
+ ret |= VM_FAULT_FALLBACK;
count_vm_event(THP_FAULT_FALLBACK);
- ret |= VM_FAULT_OOM;
goto out;
}
@@ -1545,6 +1548,7 @@ int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
entry = pmd_mknonnuma(entry);
entry = pmd_modify(entry, newprot);
ret = HPAGE_PMD_NR;
+ set_pmd_at(mm, addr, pmd, entry);
BUG_ON(pmd_write(entry));
} else {
struct page *page = pmd_page(*pmd);
@@ -1557,16 +1561,10 @@ int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
*/
if (!is_huge_zero_page(page) &&
!pmd_numa(*pmd)) {
- entry = *pmd;
- entry = pmd_mknuma(entry);
+ pmdp_set_numa(mm, addr, pmd);
ret = HPAGE_PMD_NR;
}
}
-
- /* Set PMD if cleared earlier */
- if (ret == HPAGE_PMD_NR)
- set_pmd_at(mm, addr, pmd, entry);
-
spin_unlock(ptl);
}
@@ -1963,7 +1961,7 @@ out:
return ret;
}
-#define VM_NO_THP (VM_SPECIAL|VM_MIXEDMAP|VM_HUGETLB|VM_SHARED|VM_MAYSHARE)
+#define VM_NO_THP (VM_SPECIAL | VM_HUGETLB | VM_SHARED | VM_MAYSHARE)
int hugepage_madvise(struct vm_area_struct *vma,
unsigned long *vm_flags, int advice)
diff --git a/mm/ksm.c b/mm/ksm.c
index aa4c7c7250c1..68710e80994a 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -444,7 +444,7 @@ static void break_cow(struct rmap_item *rmap_item)
static struct page *page_trans_compound_anon(struct page *page)
{
if (PageTransCompound(page)) {
- struct page *head = compound_trans_head(page);
+ struct page *head = compound_head(page);
/*
* head may actually be splitted and freed from under
* us but it's ok here.
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 19d5d4274e22..5b6b0039f725 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1127,8 +1127,8 @@ skip_node:
* skipping css reference should be safe.
*/
if (next_css) {
- if ((next_css->flags & CSS_ONLINE) &&
- (next_css == &root->css || css_tryget(next_css)))
+ if ((next_css == &root->css) ||
+ ((next_css->flags & CSS_ONLINE) && css_tryget(next_css)))
return mem_cgroup_from_css(next_css);
prev_css = next_css;
@@ -1687,7 +1687,7 @@ void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p)
* protects memcg_name and makes sure that parallel ooms do not
* interleave
*/
- static DEFINE_SPINLOCK(oom_info_lock);
+ static DEFINE_MUTEX(oom_info_lock);
struct cgroup *task_cgrp;
struct cgroup *mem_cgrp;
static char memcg_name[PATH_MAX];
@@ -1698,7 +1698,7 @@ void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p)
if (!p)
return;
- spin_lock(&oom_info_lock);
+ mutex_lock(&oom_info_lock);
rcu_read_lock();
mem_cgrp = memcg->css.cgroup;
@@ -1767,7 +1767,7 @@ done:
pr_cont("\n");
}
- spin_unlock(&oom_info_lock);
+ mutex_unlock(&oom_info_lock);
}
/*
@@ -3400,7 +3400,7 @@ void mem_cgroup_destroy_cache(struct kmem_cache *cachep)
static struct kmem_cache *memcg_create_kmem_cache(struct mem_cgroup *memcg,
struct kmem_cache *s)
{
- struct kmem_cache *new;
+ struct kmem_cache *new = NULL;
static char *tmp_name = NULL;
static DEFINE_MUTEX(mutex); /* protects tmp_name */
@@ -3416,7 +3416,7 @@ static struct kmem_cache *memcg_create_kmem_cache(struct mem_cgroup *memcg,
if (!tmp_name) {
tmp_name = kmalloc(PATH_MAX, GFP_KERNEL);
if (!tmp_name)
- return NULL;
+ goto out;
}
rcu_read_lock();
@@ -3426,12 +3426,11 @@ static struct kmem_cache *memcg_create_kmem_cache(struct mem_cgroup *memcg,
new = kmem_cache_create_memcg(memcg, tmp_name, s->object_size, s->align,
(s->flags & ~SLAB_PANIC), s->ctor, s);
-
if (new)
new->allocflags |= __GFP_KMEMCG;
else
new = s;
-
+out:
mutex_unlock(&mutex);
return new;
}
@@ -6596,6 +6595,7 @@ static void mem_cgroup_css_offline(struct cgroup_subsys_state *css)
{
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
struct mem_cgroup_event *event, *tmp;
+ struct cgroup_subsys_state *iter;
/*
* Unregister events and notify userspace.
@@ -6612,7 +6612,14 @@ static void mem_cgroup_css_offline(struct cgroup_subsys_state *css)
kmem_cgroup_css_offline(memcg);
mem_cgroup_invalidate_reclaim_iterators(memcg);
- mem_cgroup_reparent_charges(memcg);
+
+ /*
+ * This requires that offlining is serialized. Right now that is
+ * guaranteed because css_killed_work_fn() holds the cgroup_mutex.
+ */
+ css_for_each_descendant_post(iter, css)
+ mem_cgroup_reparent_charges(mem_cgroup_from_css(iter));
+
mem_cgroup_destroy_all_caches(memcg);
vmpressure_cleanup(&memcg->vmpressure);
}
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 4f08a2d61487..90002ea43638 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -945,8 +945,10 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn,
* to it. Similarly, page lock is shifted.
*/
if (hpage != p) {
- put_page(hpage);
- get_page(p);
+ if (!(flags & MF_COUNT_INCREASED)) {
+ put_page(hpage);
+ get_page(p);
+ }
lock_page(p);
unlock_page(hpage);
*hpagep = p;
@@ -1649,7 +1651,7 @@ int soft_offline_page(struct page *page, int flags)
{
int ret;
unsigned long pfn = page_to_pfn(page);
- struct page *hpage = compound_trans_head(page);
+ struct page *hpage = compound_head(page);
if (PageHWPoison(page)) {
pr_info("soft offline: %#lx page already poisoned\n", pfn);
diff --git a/mm/memory.c b/mm/memory.c
index be6a0c0d4ae0..22dfa617bddb 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3348,6 +3348,7 @@ static int __do_fault(struct mm_struct *mm, struct vm_area_struct *vma,
if (ret & VM_FAULT_LOCKED)
unlock_page(vmf.page);
ret = VM_FAULT_HWPOISON;
+ page_cache_release(vmf.page);
goto uncharge_out;
}
@@ -3703,7 +3704,6 @@ static int __handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma,
if (unlikely(is_vm_hugetlb_page(vma)))
return hugetlb_fault(mm, vma, address, flags);
-retry:
pgd = pgd_offset(mm, address);
pud = pud_alloc(mm, pgd, address);
if (!pud)
@@ -3741,20 +3741,13 @@ retry:
if (dirty && !pmd_write(orig_pmd)) {
ret = do_huge_pmd_wp_page(mm, vma, address, pmd,
orig_pmd);
- /*
- * If COW results in an oom, the huge pmd will
- * have been split, so retry the fault on the
- * pte for a smaller charge.
- */
- if (unlikely(ret & VM_FAULT_OOM))
- goto retry;
- return ret;
+ if (!(ret & VM_FAULT_FALLBACK))
+ return ret;
} else {
huge_pmd_set_accessed(mm, vma, address, pmd,
orig_pmd, dirty);
+ return 0;
}
-
- return 0;
}
}
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 873de7e542bc..ae3c8f3595d4 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -2930,7 +2930,7 @@ void mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol)
unsigned short mode = MPOL_DEFAULT;
unsigned short flags = 0;
- if (pol && pol != &default_policy) {
+ if (pol && pol != &default_policy && !(pol->flags & MPOL_F_MORON)) {
mode = pol->mode;
flags = pol->flags;
}
diff --git a/mm/migrate.c b/mm/migrate.c
index 482a33d89134..b494fdb9a636 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1158,7 +1158,7 @@ static struct page *new_page_node(struct page *p, unsigned long private,
pm->node);
else
return alloc_pages_exact_node(pm->node,
- GFP_HIGHUSER_MOVABLE | GFP_THISNODE, 0);
+ GFP_HIGHUSER_MOVABLE | __GFP_THISNODE, 0);
}
/*
@@ -1544,9 +1544,9 @@ static struct page *alloc_misplaced_dst_page(struct page *page,
struct page *newpage;
newpage = alloc_pages_exact_node(nid,
- (GFP_HIGHUSER_MOVABLE | GFP_THISNODE |
- __GFP_NOMEMALLOC | __GFP_NORETRY |
- __GFP_NOWARN) &
+ (GFP_HIGHUSER_MOVABLE |
+ __GFP_THISNODE | __GFP_NOMEMALLOC |
+ __GFP_NORETRY | __GFP_NOWARN) &
~GFP_IOFS, 0);
return newpage;
@@ -1747,7 +1747,8 @@ int migrate_misplaced_transhuge_page(struct mm_struct *mm,
goto out_dropref;
new_page = alloc_pages_node(node,
- (GFP_TRANSHUGE | GFP_THISNODE) & ~__GFP_WAIT, HPAGE_PMD_ORDER);
+ (GFP_TRANSHUGE | __GFP_THISNODE) & ~__GFP_WAIT,
+ HPAGE_PMD_ORDER);
if (!new_page)
goto out_fail;
diff --git a/mm/mprotect.c b/mm/mprotect.c
index 7332c1785744..769a67a15803 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -58,36 +58,27 @@ static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
if (pte_numa(ptent))
ptent = pte_mknonnuma(ptent);
ptent = pte_modify(ptent, newprot);
+ /*
+ * Avoid taking write faults for pages we
+ * know to be dirty.
+ */
+ if (dirty_accountable && pte_dirty(ptent))
+ ptent = pte_mkwrite(ptent);
+ ptep_modify_prot_commit(mm, addr, pte, ptent);
updated = true;
} else {
struct page *page;
- ptent = *pte;
page = vm_normal_page(vma, addr, oldpte);
if (page && !PageKsm(page)) {
if (!pte_numa(oldpte)) {
- ptent = pte_mknuma(ptent);
- set_pte_at(mm, addr, pte, ptent);
+ ptep_set_numa(mm, addr, pte);
updated = true;
}
}
}
-
- /*
- * Avoid taking write faults for pages we know to be
- * dirty.
- */
- if (dirty_accountable && pte_dirty(ptent)) {
- ptent = pte_mkwrite(ptent);
- updated = true;
- }
-
if (updated)
pages++;
-
- /* Only !prot_numa always clears the pte */
- if (!prot_numa)
- ptep_modify_prot_commit(mm, addr, pte, ptent);
} else if (IS_ENABLED(CONFIG_MIGRATION) && !pte_file(oldpte)) {
swp_entry_t entry = pte_to_swp_entry(oldpte);
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 37b1b1903fb2..3291e82d4352 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -178,7 +178,7 @@ unsigned long oom_badness(struct task_struct *p, struct mem_cgroup *memcg,
* implementation used by LSMs.
*/
if (has_capability_noaudit(p, CAP_SYS_ADMIN))
- adj -= 30;
+ points -= (points * 3) / 100;
/* Normalize to oom_score_adj units */
adj *= totalpages / 1000;
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 2d30e2cfe804..7106cb1aca8e 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -2173,11 +2173,12 @@ int __set_page_dirty_nobuffers(struct page *page)
if (!TestSetPageDirty(page)) {
struct address_space *mapping = page_mapping(page);
struct address_space *mapping2;
+ unsigned long flags;
if (!mapping)
return 1;
- spin_lock_irq(&mapping->tree_lock);
+ spin_lock_irqsave(&mapping->tree_lock, flags);
mapping2 = page_mapping(page);
if (mapping2) { /* Race with truncate? */
BUG_ON(mapping2 != mapping);
@@ -2186,7 +2187,7 @@ int __set_page_dirty_nobuffers(struct page *page)
radix_tree_tag_set(&mapping->page_tree,
page_index(page), PAGECACHE_TAG_DIRTY);
}
- spin_unlock_irq(&mapping->tree_lock);
+ spin_unlock_irqrestore(&mapping->tree_lock, flags);
if (mapping->host) {
/* !PageAnon && !swapper_space */
__mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index e3758a09a009..3bac76ae4b30 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -369,9 +369,11 @@ void prep_compound_page(struct page *page, unsigned long order)
__SetPageHead(page);
for (i = 1; i < nr_pages; i++) {
struct page *p = page + i;
- __SetPageTail(p);
set_page_count(p, 0);
p->first_page = page;
+ /* Make sure p->first_page is always valid for PageTail() */
+ smp_wmb();
+ __SetPageTail(p);
}
}
@@ -1236,6 +1238,15 @@ void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
}
local_irq_restore(flags);
}
+static bool gfp_thisnode_allocation(gfp_t gfp_mask)
+{
+ return (gfp_mask & GFP_THISNODE) == GFP_THISNODE;
+}
+#else
+static bool gfp_thisnode_allocation(gfp_t gfp_mask)
+{
+ return false;
+}
#endif
/*
@@ -1572,7 +1583,13 @@ again:
get_pageblock_migratetype(page));
}
- __mod_zone_page_state(zone, NR_ALLOC_BATCH, -(1 << order));
+ /*
+ * NOTE: GFP_THISNODE allocations do not partake in the kswapd
+ * aging protocol, so they can't be fair.
+ */
+ if (!gfp_thisnode_allocation(gfp_flags))
+ __mod_zone_page_state(zone, NR_ALLOC_BATCH, -(1 << order));
+
__count_zone_vm_events(PGALLOC, zone, 1 << order);
zone_statistics(preferred_zone, zone, gfp_flags);
local_irq_restore(flags);
@@ -1944,8 +1961,12 @@ zonelist_scan:
* ultimately fall back to remote zones that do not
* partake in the fairness round-robin cycle of this
* zonelist.
+ *
+ * NOTE: GFP_THISNODE allocations do not partake in
+ * the kswapd aging protocol, so they can't be fair.
*/
- if (alloc_flags & ALLOC_WMARK_LOW) {
+ if ((alloc_flags & ALLOC_WMARK_LOW) &&
+ !gfp_thisnode_allocation(gfp_mask)) {
if (zone_page_state(zone, NR_ALLOC_BATCH) <= 0)
continue;
if (!zone_local(preferred_zone, zone))
@@ -2501,8 +2522,7 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
* allowed per node queues are empty and that nodes are
* over allocated.
*/
- if (IS_ENABLED(CONFIG_NUMA) &&
- (gfp_mask & GFP_THISNODE) == GFP_THISNODE)
+ if (gfp_thisnode_allocation(gfp_mask))
goto nopage;
restart:
diff --git a/mm/slab.c b/mm/slab.c
index eb043bf05f4c..b264214c77ea 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -1946,7 +1946,7 @@ static void slab_destroy_debugcheck(struct kmem_cache *cachep,
/**
* slab_destroy - destroy and release all objects in a slab
* @cachep: cache pointer being destroyed
- * @slabp: slab pointer being destroyed
+ * @page: page pointer being destroyed
*
* Destroy all the objs in a slab, and release the mem back to the system.
* Before calling the slab must have been unlinked from the cache. The
diff --git a/mm/slub.c b/mm/slub.c
index 545a170ebf9f..25f14ad8f817 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -355,6 +355,21 @@ static __always_inline void slab_unlock(struct page *page)
__bit_spin_unlock(PG_locked, &page->flags);
}
+static inline void set_page_slub_counters(struct page *page, unsigned long counters_new)
+{
+ struct page tmp;
+ tmp.counters = counters_new;
+ /*
+ * page->counters can cover frozen/inuse/objects as well
+ * as page->_count. If we assign to ->counters directly
+ * we run the risk of losing updates to page->_count, so
+ * be careful and only assign to the fields we need.
+ */
+ page->frozen = tmp.frozen;
+ page->inuse = tmp.inuse;
+ page->objects = tmp.objects;
+}
+
/* Interrupts must be disabled (for the fallback code to work right) */
static inline bool __cmpxchg_double_slab(struct kmem_cache *s, struct page *page,
void *freelist_old, unsigned long counters_old,
@@ -376,7 +391,7 @@ static inline bool __cmpxchg_double_slab(struct kmem_cache *s, struct page *page
if (page->freelist == freelist_old &&
page->counters == counters_old) {
page->freelist = freelist_new;
- page->counters = counters_new;
+ set_page_slub_counters(page, counters_new);
slab_unlock(page);
return 1;
}
@@ -415,7 +430,7 @@ static inline bool cmpxchg_double_slab(struct kmem_cache *s, struct page *page,
if (page->freelist == freelist_old &&
page->counters == counters_old) {
page->freelist = freelist_new;
- page->counters = counters_new;
+ set_page_slub_counters(page, counters_new);
slab_unlock(page);
local_irq_restore(flags);
return 1;
@@ -985,8 +1000,6 @@ static inline void slab_free_hook(struct kmem_cache *s, void *x)
/*
* Tracking of fully allocated slabs for debugging purposes.
- *
- * list_lock must be held.
*/
static void add_full(struct kmem_cache *s,
struct kmem_cache_node *n, struct page *page)
@@ -994,17 +1007,16 @@ static void add_full(struct kmem_cache *s,
if (!(s->flags & SLAB_STORE_USER))
return;
+ lockdep_assert_held(&n->list_lock);
list_add(&page->lru, &n->full);
}
-/*
- * list_lock must be held.
- */
-static void remove_full(struct kmem_cache *s, struct page *page)
+static void remove_full(struct kmem_cache *s, struct kmem_cache_node *n, struct page *page)
{
if (!(s->flags & SLAB_STORE_USER))
return;
+ lockdep_assert_held(&n->list_lock);
list_del(&page->lru);
}
@@ -1250,7 +1262,8 @@ static inline int check_object(struct kmem_cache *s, struct page *page,
void *object, u8 val) { return 1; }
static inline void add_full(struct kmem_cache *s, struct kmem_cache_node *n,
struct page *page) {}
-static inline void remove_full(struct kmem_cache *s, struct page *page) {}
+static inline void remove_full(struct kmem_cache *s, struct kmem_cache_node *n,
+ struct page *page) {}
static inline unsigned long kmem_cache_flags(unsigned long object_size,
unsigned long flags, const char *name,
void (*ctor)(void *))
@@ -1504,11 +1517,9 @@ static void discard_slab(struct kmem_cache *s, struct page *page)
/*
* Management of partially allocated slabs.
- *
- * list_lock must be held.
*/
-static inline void add_partial(struct kmem_cache_node *n,
- struct page *page, int tail)
+static inline void
+__add_partial(struct kmem_cache_node *n, struct page *page, int tail)
{
n->nr_partial++;
if (tail == DEACTIVATE_TO_TAIL)
@@ -1517,23 +1528,32 @@ static inline void add_partial(struct kmem_cache_node *n,
list_add(&page->lru, &n->partial);
}
-/*
- * list_lock must be held.
- */
-static inline void remove_partial(struct kmem_cache_node *n,
- struct page *page)
+static inline void add_partial(struct kmem_cache_node *n,
+ struct page *page, int tail)
+{
+ lockdep_assert_held(&n->list_lock);
+ __add_partial(n, page, tail);
+}
+
+static inline void
+__remove_partial(struct kmem_cache_node *n, struct page *page)
{
list_del(&page->lru);
n->nr_partial--;
}
+static inline void remove_partial(struct kmem_cache_node *n,
+ struct page *page)
+{
+ lockdep_assert_held(&n->list_lock);
+ __remove_partial(n, page);
+}
+
/*
* Remove slab from the partial list, freeze it and
* return the pointer to the freelist.
*
* Returns a list of objects or NULL if it fails.
- *
- * Must hold list_lock since we modify the partial list.
*/
static inline void *acquire_slab(struct kmem_cache *s,
struct kmem_cache_node *n, struct page *page,
@@ -1543,6 +1563,8 @@ static inline void *acquire_slab(struct kmem_cache *s,
unsigned long counters;
struct page new;
+ lockdep_assert_held(&n->list_lock);
+
/*
* Zap the freelist and set the frozen bit.
* The old freelist is the list of objects for the
@@ -1887,7 +1909,7 @@ redo:
else if (l == M_FULL)
- remove_full(s, page);
+ remove_full(s, n, page);
if (m == M_PARTIAL) {
@@ -2541,7 +2563,7 @@ static void __slab_free(struct kmem_cache *s, struct page *page,
new.inuse--;
if ((!new.inuse || !prior) && !was_frozen) {
- if (kmem_cache_has_cpu_partial(s) && !prior)
+ if (kmem_cache_has_cpu_partial(s) && !prior) {
/*
* Slab was on no list before and will be
@@ -2551,7 +2573,7 @@ static void __slab_free(struct kmem_cache *s, struct page *page,
*/
new.frozen = 1;
- else { /* Needs to be taken off a list */
+ } else { /* Needs to be taken off a list */
n = get_node(s, page_to_nid(page));
/*
@@ -2600,7 +2622,7 @@ static void __slab_free(struct kmem_cache *s, struct page *page,
*/
if (!kmem_cache_has_cpu_partial(s) && unlikely(!prior)) {
if (kmem_cache_debug(s))
- remove_full(s, page);
+ remove_full(s, n, page);
add_partial(n, page, DEACTIVATE_TO_TAIL);
stat(s, FREE_ADD_PARTIAL);
}
@@ -2614,9 +2636,10 @@ slab_empty:
*/
remove_partial(n, page);
stat(s, FREE_REMOVE_PARTIAL);
- } else
+ } else {
/* Slab must be on the full list */
- remove_full(s, page);
+ remove_full(s, n, page);
+ }
spin_unlock_irqrestore(&n->list_lock, flags);
stat(s, FREE_SLAB);
@@ -2890,7 +2913,11 @@ static void early_kmem_cache_node_alloc(int node)
init_kmem_cache_node(n);
inc_slabs_node(kmem_cache_node, node, page->objects);
- add_partial(n, page, DEACTIVATE_TO_HEAD);
+ /*
+ * No locks need to be taken here as it has just been
+ * initialized and there is no concurrent access.
+ */
+ __add_partial(n, page, DEACTIVATE_TO_HEAD);
}
static void free_kmem_cache_nodes(struct kmem_cache *s)
@@ -3176,7 +3203,7 @@ static void free_partial(struct kmem_cache *s, struct kmem_cache_node *n)
list_for_each_entry_safe(page, h, &n->partial, lru) {
if (!page->inuse) {
- remove_partial(n, page);
+ __remove_partial(n, page);
discard_slab(s, page);
} else {
list_slab_objects(s, page,
@@ -4299,7 +4326,13 @@ static ssize_t show_slab_objects(struct kmem_cache *s,
page = ACCESS_ONCE(c->partial);
if (page) {
- x = page->pobjects;
+ node = page_to_nid(page);
+ if (flags & SO_TOTAL)
+ WARN_ON_ONCE(1);
+ else if (flags & SO_OBJECTS)
+ WARN_ON_ONCE(1);
+ else
+ x = page->pages;
total += x;
nodes[node] += x;
}
@@ -5163,7 +5196,7 @@ static int sysfs_slab_add(struct kmem_cache *s)
}
s->kobj.kset = slab_kset;
- err = kobject_init_and_add(&s->kobj, &slab_ktype, NULL, name);
+ err = kobject_init_and_add(&s->kobj, &slab_ktype, NULL, "%s", name);
if (err) {
kobject_put(&s->kobj);
return err;
diff --git a/mm/swap.c b/mm/swap.c
index b31ba67d440a..0092097b3f4c 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -98,7 +98,7 @@ static void put_compound_page(struct page *page)
}
/* __split_huge_page_refcount can run under us */
- page_head = compound_trans_head(page);
+ page_head = compound_head(page);
/*
* THP can not break up slab pages so avoid taking
@@ -253,7 +253,7 @@ bool __get_page_tail(struct page *page)
*/
unsigned long flags;
bool got;
- struct page *page_head = compound_trans_head(page);
+ struct page *page_head = compound_head(page);
/* Ref to put_compound_page() comment. */
if (!__compound_tail_refcounted(page_head)) {
diff --git a/mm/swap_state.c b/mm/swap_state.c
index 98e85e9c2b2d..e76ace30d436 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -63,6 +63,8 @@ unsigned long total_swapcache_pages(void)
return ret;
}
+static atomic_t swapin_readahead_hits = ATOMIC_INIT(4);
+
void show_swap_cache_info(void)
{
printk("%lu pages in swap cache\n", total_swapcache_pages());
@@ -286,8 +288,11 @@ struct page * lookup_swap_cache(swp_entry_t entry)
page = find_get_page(swap_address_space(entry), entry.val);
- if (page)
+ if (page) {
INC_CACHE_INFO(find_success);
+ if (TestClearPageReadahead(page))
+ atomic_inc(&swapin_readahead_hits);
+ }
INC_CACHE_INFO(find_total);
return page;
@@ -389,6 +394,50 @@ struct page *read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
return found_page;
}
+static unsigned long swapin_nr_pages(unsigned long offset)
+{
+ static unsigned long prev_offset;
+ unsigned int pages, max_pages, last_ra;
+ static atomic_t last_readahead_pages;
+
+ max_pages = 1 << ACCESS_ONCE(page_cluster);
+ if (max_pages <= 1)
+ return 1;
+
+ /*
+ * This heuristic has been found to work well on both sequential and
+ * random loads, swapping to hard disk or to SSD: please don't ask
+ * what the "+ 2" means, it just happens to work well, that's all.
+ */
+ pages = atomic_xchg(&swapin_readahead_hits, 0) + 2;
+ if (pages == 2) {
+ /*
+ * We can have no readahead hits to judge by: but must not get
+ * stuck here forever, so check for an adjacent offset instead
+ * (and don't even bother to check whether swap type is same).
+ */
+ if (offset != prev_offset + 1 && offset != prev_offset - 1)
+ pages = 1;
+ prev_offset = offset;
+ } else {
+ unsigned int roundup = 4;
+ while (roundup < pages)
+ roundup <<= 1;
+ pages = roundup;
+ }
+
+ if (pages > max_pages)
+ pages = max_pages;
+
+ /* Don't shrink readahead too fast */
+ last_ra = atomic_read(&last_readahead_pages) / 2;
+ if (pages < last_ra)
+ pages = last_ra;
+ atomic_set(&last_readahead_pages, pages);
+
+ return pages;
+}
+
/**
* swapin_readahead - swap in pages in hope we need them soon
* @entry: swap entry of this memory
@@ -412,11 +461,16 @@ struct page *swapin_readahead(swp_entry_t entry, gfp_t gfp_mask,
struct vm_area_struct *vma, unsigned long addr)
{
struct page *page;
- unsigned long offset = swp_offset(entry);
+ unsigned long entry_offset = swp_offset(entry);
+ unsigned long offset = entry_offset;
unsigned long start_offset, end_offset;
- unsigned long mask = (1UL << page_cluster) - 1;
+ unsigned long mask;
struct blk_plug plug;
+ mask = swapin_nr_pages(offset) - 1;
+ if (!mask)
+ goto skip;
+
/* Read a page_cluster sized and aligned cluster around offset. */
start_offset = offset & ~mask;
end_offset = offset | mask;
@@ -430,10 +484,13 @@ struct page *swapin_readahead(swp_entry_t entry, gfp_t gfp_mask,
gfp_mask, vma, addr);
if (!page)
continue;
+ if (offset != entry_offset)
+ SetPageReadahead(page);
page_cache_release(page);
}
blk_finish_plug(&plug);
lru_add_drain(); /* Push any new pages onto the LRU now */
+skip:
return read_swap_cache_async(entry, gfp_mask, vma, addr);
}
diff --git a/mm/swapfile.c b/mm/swapfile.c
index c6c13b050a58..4a7f7e6992b6 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -1923,7 +1923,6 @@ SYSCALL_DEFINE1(swapoff, const char __user *, specialfile)
p->swap_map = NULL;
cluster_info = p->cluster_info;
p->cluster_info = NULL;
- p->flags = 0;
frontswap_map = frontswap_map_get(p);
spin_unlock(&p->lock);
spin_unlock(&swap_lock);
@@ -1949,6 +1948,16 @@ SYSCALL_DEFINE1(swapoff, const char __user *, specialfile)
mutex_unlock(&inode->i_mutex);
}
filp_close(swap_file, NULL);
+
+ /*
+ * Clear the SWP_USED flag after all resources are freed so that swapon
+ * can reuse this swap_info in alloc_swap_info() safely. It is ok to
+ * not hold p->lock after we cleared its SWP_WRITEOK.
+ */
+ spin_lock(&swap_lock);
+ p->flags = 0;
+ spin_unlock(&swap_lock);
+
err = 0;
atomic_inc(&proc_poll_event);
wake_up_interruptible(&proc_poll_wait);
diff --git a/mm/vmpressure.c b/mm/vmpressure.c
index 196970a4541f..d4042e75f7c7 100644
--- a/mm/vmpressure.c
+++ b/mm/vmpressure.c
@@ -19,6 +19,7 @@
#include <linux/mm.h>
#include <linux/vmstat.h>
#include <linux/eventfd.h>
+#include <linux/slab.h>
#include <linux/swap.h>
#include <linux/printk.h>
#include <linux/vmpressure.h>
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 72496140ac08..def5dd2fbe61 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -851,12 +851,14 @@ const char * const vmstat_text[] = {
"thp_zero_page_alloc",
"thp_zero_page_alloc_failed",
#endif
+#ifdef CONFIG_DEBUG_TLBFLUSH
#ifdef CONFIG_SMP
"nr_tlb_remote_flush",
"nr_tlb_remote_flush_received",
-#endif
+#endif /* CONFIG_SMP */
"nr_tlb_local_flush_all",
"nr_tlb_local_flush_one",
+#endif /* CONFIG_DEBUG_TLBFLUSH */
#endif /* CONFIG_VM_EVENTS_COUNTERS */
};
diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
new file mode 100644
index 000000000000..c03ca5e9fe15
--- /dev/null
+++ b/mm/zsmalloc.c
@@ -0,0 +1,1106 @@
+/*
+ * zsmalloc memory allocator
+ *
+ * Copyright (C) 2011 Nitin Gupta
+ * Copyright (C) 2012, 2013 Minchan Kim
+ *
+ * This code is released using a dual license strategy: BSD/GPL
+ * You can choose the license that better fits your requirements.
+ *
+ * Released under the terms of 3-clause BSD License
+ * Released under the terms of GNU General Public License Version 2.0
+ */
+
+/*
+ * This allocator is designed for use with zram. Thus, the allocator is
+ * supposed to work well under low memory conditions. In particular, it
+ * never attempts higher order page allocation which is very likely to
+ * fail under memory pressure. On the other hand, if we just use single
+ * (0-order) pages, it would suffer from very high fragmentation --
+ * any object of size PAGE_SIZE/2 or larger would occupy an entire page.
+ * This was one of the major issues with its predecessor (xvmalloc).
+ *
+ * To overcome these issues, zsmalloc allocates a bunch of 0-order pages
+ * and links them together using various 'struct page' fields. These linked
+ * pages act as a single higher-order page i.e. an object can span 0-order
+ * page boundaries. The code refers to these linked pages as a single entity
+ * called zspage.
+ *
+ * For simplicity, zsmalloc can only allocate objects of size up to PAGE_SIZE
+ * since this satisfies the requirements of all its current users (in the
+ * worst case, page is incompressible and is thus stored "as-is" i.e. in
+ * uncompressed form). For allocation requests larger than this size, failure
+ * is returned (see zs_malloc).
+ *
+ * Additionally, zs_malloc() does not return a dereferenceable pointer.
+ * Instead, it returns an opaque handle (unsigned long) which encodes actual
+ * location of the allocated object. The reason for this indirection is that
+ * zsmalloc does not keep zspages permanently mapped since that would cause
+ * issues on 32-bit systems where the VA region for kernel space mappings
+ * is very small. So, before using the allocating memory, the object has to
+ * be mapped using zs_map_object() to get a usable pointer and subsequently
+ * unmapped using zs_unmap_object().
+ *
+ * Following is how we use various fields and flags of underlying
+ * struct page(s) to form a zspage.
+ *
+ * Usage of struct page fields:
+ * page->first_page: points to the first component (0-order) page
+ * page->index (union with page->freelist): offset of the first object
+ * starting in this page. For the first page, this is
+ * always 0, so we use this field (aka freelist) to point
+ * to the first free object in zspage.
+ * page->lru: links together all component pages (except the first page)
+ * of a zspage
+ *
+ * For _first_ page only:
+ *
+ * page->private (union with page->first_page): refers to the
+ * component page after the first page
+ * page->freelist: points to the first free object in zspage.
+ * Free objects are linked together using in-place
+ * metadata.
+ * page->objects: maximum number of objects we can store in this
+ * zspage (class->zspage_order * PAGE_SIZE / class->size)
+ * page->lru: links together first pages of various zspages.
+ * Basically forming list of zspages in a fullness group.
+ * page->mapping: class index and fullness group of the zspage
+ *
+ * Usage of struct page flags:
+ * PG_private: identifies the first component page
+ * PG_private2: identifies the last component page
+ *
+ */
+
+#ifdef CONFIG_ZSMALLOC_DEBUG
+#define DEBUG
+#endif
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/bitops.h>
+#include <linux/errno.h>
+#include <linux/highmem.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <asm/tlbflush.h>
+#include <asm/pgtable.h>
+#include <linux/cpumask.h>
+#include <linux/cpu.h>
+#include <linux/vmalloc.h>
+#include <linux/hardirq.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+#include <linux/zsmalloc.h>
+
+/*
+ * This must be power of 2 and greater than of equal to sizeof(link_free).
+ * These two conditions ensure that any 'struct link_free' itself doesn't
+ * span more than 1 page which avoids complex case of mapping 2 pages simply
+ * to restore link_free pointer values.
+ */
+#define ZS_ALIGN 8
+
+/*
+ * A single 'zspage' is composed of up to 2^N discontiguous 0-order (single)
+ * pages. ZS_MAX_ZSPAGE_ORDER defines upper limit on N.
+ */
+#define ZS_MAX_ZSPAGE_ORDER 2
+#define ZS_MAX_PAGES_PER_ZSPAGE (_AC(1, UL) << ZS_MAX_ZSPAGE_ORDER)
+
+/*
+ * Object location (<PFN>, <obj_idx>) is encoded as
+ * as single (unsigned long) handle value.
+ *
+ * Note that object index <obj_idx> is relative to system
+ * page <PFN> it is stored in, so for each sub-page belonging
+ * to a zspage, obj_idx starts with 0.
+ *
+ * This is made more complicated by various memory models and PAE.
+ */
+
+#ifndef MAX_PHYSMEM_BITS
+#ifdef CONFIG_HIGHMEM64G
+#define MAX_PHYSMEM_BITS 36
+#else /* !CONFIG_HIGHMEM64G */
+/*
+ * If this definition of MAX_PHYSMEM_BITS is used, OBJ_INDEX_BITS will just
+ * be PAGE_SHIFT
+ */
+#define MAX_PHYSMEM_BITS BITS_PER_LONG
+#endif
+#endif
+#define _PFN_BITS (MAX_PHYSMEM_BITS - PAGE_SHIFT)
+#define OBJ_INDEX_BITS (BITS_PER_LONG - _PFN_BITS)
+#define OBJ_INDEX_MASK ((_AC(1, UL) << OBJ_INDEX_BITS) - 1)
+
+#define MAX(a, b) ((a) >= (b) ? (a) : (b))
+/* ZS_MIN_ALLOC_SIZE must be multiple of ZS_ALIGN */
+#define ZS_MIN_ALLOC_SIZE \
+ MAX(32, (ZS_MAX_PAGES_PER_ZSPAGE << PAGE_SHIFT >> OBJ_INDEX_BITS))
+#define ZS_MAX_ALLOC_SIZE PAGE_SIZE
+
+/*
+ * On systems with 4K page size, this gives 254 size classes! There is a
+ * trader-off here:
+ * - Large number of size classes is potentially wasteful as free page are
+ * spread across these classes
+ * - Small number of size classes causes large internal fragmentation
+ * - Probably its better to use specific size classes (empirically
+ * determined). NOTE: all those class sizes must be set as multiple of
+ * ZS_ALIGN to make sure link_free itself never has to span 2 pages.
+ *
+ * ZS_MIN_ALLOC_SIZE and ZS_SIZE_CLASS_DELTA must be multiple of ZS_ALIGN
+ * (reason above)
+ */
+#define ZS_SIZE_CLASS_DELTA (PAGE_SIZE >> 8)
+#define ZS_SIZE_CLASSES ((ZS_MAX_ALLOC_SIZE - ZS_MIN_ALLOC_SIZE) / \
+ ZS_SIZE_CLASS_DELTA + 1)
+
+/*
+ * We do not maintain any list for completely empty or full pages
+ */
+enum fullness_group {
+ ZS_ALMOST_FULL,
+ ZS_ALMOST_EMPTY,
+ _ZS_NR_FULLNESS_GROUPS,
+
+ ZS_EMPTY,
+ ZS_FULL
+};
+
+/*
+ * We assign a page to ZS_ALMOST_EMPTY fullness group when:
+ * n <= N / f, where
+ * n = number of allocated objects
+ * N = total number of objects zspage can store
+ * f = 1/fullness_threshold_frac
+ *
+ * Similarly, we assign zspage to:
+ * ZS_ALMOST_FULL when n > N / f
+ * ZS_EMPTY when n == 0
+ * ZS_FULL when n == N
+ *
+ * (see: fix_fullness_group())
+ */
+static const int fullness_threshold_frac = 4;
+
+struct size_class {
+ /*
+ * Size of objects stored in this class. Must be multiple
+ * of ZS_ALIGN.
+ */
+ int size;
+ unsigned int index;
+
+ /* Number of PAGE_SIZE sized pages to combine to form a 'zspage' */
+ int pages_per_zspage;
+
+ spinlock_t lock;
+
+ /* stats */
+ u64 pages_allocated;
+
+ struct page *fullness_list[_ZS_NR_FULLNESS_GROUPS];
+};
+
+/*
+ * Placed within free objects to form a singly linked list.
+ * For every zspage, first_page->freelist gives head of this list.
+ *
+ * This must be power of 2 and less than or equal to ZS_ALIGN
+ */
+struct link_free {
+ /* Handle of next free chunk (encodes <PFN, obj_idx>) */
+ void *next;
+};
+
+struct zs_pool {
+ struct size_class size_class[ZS_SIZE_CLASSES];
+
+ gfp_t flags; /* allocation flags used when growing pool */
+};
+
+/*
+ * A zspage's class index and fullness group
+ * are encoded in its (first)page->mapping
+ */
+#define CLASS_IDX_BITS 28
+#define FULLNESS_BITS 4
+#define CLASS_IDX_MASK ((1 << CLASS_IDX_BITS) - 1)
+#define FULLNESS_MASK ((1 << FULLNESS_BITS) - 1)
+
+struct mapping_area {
+#ifdef CONFIG_PGTABLE_MAPPING
+ struct vm_struct *vm; /* vm area for mapping object that span pages */
+#else
+ char *vm_buf; /* copy buffer for objects that span pages */
+#endif
+ char *vm_addr; /* address of kmap_atomic()'ed pages */
+ enum zs_mapmode vm_mm; /* mapping mode */
+};
+
+
+/* per-cpu VM mapping areas for zspage accesses that cross page boundaries */
+static DEFINE_PER_CPU(struct mapping_area, zs_map_area);
+
+static int is_first_page(struct page *page)
+{
+ return PagePrivate(page);
+}
+
+static int is_last_page(struct page *page)
+{
+ return PagePrivate2(page);
+}
+
+static void get_zspage_mapping(struct page *page, unsigned int *class_idx,
+ enum fullness_group *fullness)
+{
+ unsigned long m;
+ BUG_ON(!is_first_page(page));
+
+ m = (unsigned long)page->mapping;
+ *fullness = m & FULLNESS_MASK;
+ *class_idx = (m >> FULLNESS_BITS) & CLASS_IDX_MASK;
+}
+
+static void set_zspage_mapping(struct page *page, unsigned int class_idx,
+ enum fullness_group fullness)
+{
+ unsigned long m;
+ BUG_ON(!is_first_page(page));
+
+ m = ((class_idx & CLASS_IDX_MASK) << FULLNESS_BITS) |
+ (fullness & FULLNESS_MASK);
+ page->mapping = (struct address_space *)m;
+}
+
+/*
+ * zsmalloc divides the pool into various size classes where each
+ * class maintains a list of zspages where each zspage is divided
+ * into equal sized chunks. Each allocation falls into one of these
+ * classes depending on its size. This function returns index of the
+ * size class which has chunk size big enough to hold the give size.
+ */
+static int get_size_class_index(int size)
+{
+ int idx = 0;
+
+ if (likely(size > ZS_MIN_ALLOC_SIZE))
+ idx = DIV_ROUND_UP(size - ZS_MIN_ALLOC_SIZE,
+ ZS_SIZE_CLASS_DELTA);
+
+ return idx;
+}
+
+/*
+ * For each size class, zspages are divided into different groups
+ * depending on how "full" they are. This was done so that we could
+ * easily find empty or nearly empty zspages when we try to shrink
+ * the pool (not yet implemented). This function returns fullness
+ * status of the given page.
+ */
+static enum fullness_group get_fullness_group(struct page *page)
+{
+ int inuse, max_objects;
+ enum fullness_group fg;
+ BUG_ON(!is_first_page(page));
+
+ inuse = page->inuse;
+ max_objects = page->objects;
+
+ if (inuse == 0)
+ fg = ZS_EMPTY;
+ else if (inuse == max_objects)
+ fg = ZS_FULL;
+ else if (inuse <= max_objects / fullness_threshold_frac)
+ fg = ZS_ALMOST_EMPTY;
+ else
+ fg = ZS_ALMOST_FULL;
+
+ return fg;
+}
+
+/*
+ * Each size class maintains various freelists and zspages are assigned
+ * to one of these freelists based on the number of live objects they
+ * have. This functions inserts the given zspage into the freelist
+ * identified by <class, fullness_group>.
+ */
+static void insert_zspage(struct page *page, struct size_class *class,
+ enum fullness_group fullness)
+{
+ struct page **head;
+
+ BUG_ON(!is_first_page(page));
+
+ if (fullness >= _ZS_NR_FULLNESS_GROUPS)
+ return;
+
+ head = &class->fullness_list[fullness];
+ if (*head)
+ list_add_tail(&page->lru, &(*head)->lru);
+
+ *head = page;
+}
+
+/*
+ * This function removes the given zspage from the freelist identified
+ * by <class, fullness_group>.
+ */
+static void remove_zspage(struct page *page, struct size_class *class,
+ enum fullness_group fullness)
+{
+ struct page **head;
+
+ BUG_ON(!is_first_page(page));
+
+ if (fullness >= _ZS_NR_FULLNESS_GROUPS)
+ return;
+
+ head = &class->fullness_list[fullness];
+ BUG_ON(!*head);
+ if (list_empty(&(*head)->lru))
+ *head = NULL;
+ else if (*head == page)
+ *head = (struct page *)list_entry((*head)->lru.next,
+ struct page, lru);
+
+ list_del_init(&page->lru);
+}
+
+/*
+ * Each size class maintains zspages in different fullness groups depending
+ * on the number of live objects they contain. When allocating or freeing
+ * objects, the fullness status of the page can change, say, from ALMOST_FULL
+ * to ALMOST_EMPTY when freeing an object. This function checks if such
+ * a status change has occurred for the given page and accordingly moves the
+ * page from the freelist of the old fullness group to that of the new
+ * fullness group.
+ */
+static enum fullness_group fix_fullness_group(struct zs_pool *pool,
+ struct page *page)
+{
+ int class_idx;
+ struct size_class *class;
+ enum fullness_group currfg, newfg;
+
+ BUG_ON(!is_first_page(page));
+
+ get_zspage_mapping(page, &class_idx, &currfg);
+ newfg = get_fullness_group(page);
+ if (newfg == currfg)
+ goto out;
+
+ class = &pool->size_class[class_idx];
+ remove_zspage(page, class, currfg);
+ insert_zspage(page, class, newfg);
+ set_zspage_mapping(page, class_idx, newfg);
+
+out:
+ return newfg;
+}
+
+/*
+ * We have to decide on how many pages to link together
+ * to form a zspage for each size class. This is important
+ * to reduce wastage due to unusable space left at end of
+ * each zspage which is given as:
+ * wastage = Zp - Zp % size_class
+ * where Zp = zspage size = k * PAGE_SIZE where k = 1, 2, ...
+ *
+ * For example, for size class of 3/8 * PAGE_SIZE, we should
+ * link together 3 PAGE_SIZE sized pages to form a zspage
+ * since then we can perfectly fit in 8 such objects.
+ */
+static int get_pages_per_zspage(int class_size)
+{
+ int i, max_usedpc = 0;
+ /* zspage order which gives maximum used size per KB */
+ int max_usedpc_order = 1;
+
+ for (i = 1; i <= ZS_MAX_PAGES_PER_ZSPAGE; i++) {
+ int zspage_size;
+ int waste, usedpc;
+
+ zspage_size = i * PAGE_SIZE;
+ waste = zspage_size % class_size;
+ usedpc = (zspage_size - waste) * 100 / zspage_size;
+
+ if (usedpc > max_usedpc) {
+ max_usedpc = usedpc;
+ max_usedpc_order = i;
+ }
+ }
+
+ return max_usedpc_order;
+}
+
+/*
+ * A single 'zspage' is composed of many system pages which are
+ * linked together using fields in struct page. This function finds
+ * the first/head page, given any component page of a zspage.
+ */
+static struct page *get_first_page(struct page *page)
+{
+ if (is_first_page(page))
+ return page;
+ else
+ return page->first_page;
+}
+
+static struct page *get_next_page(struct page *page)
+{
+ struct page *next;
+
+ if (is_last_page(page))
+ next = NULL;
+ else if (is_first_page(page))
+ next = (struct page *)page_private(page);
+ else
+ next = list_entry(page->lru.next, struct page, lru);
+
+ return next;
+}
+
+/*
+ * Encode <page, obj_idx> as a single handle value.
+ * On hardware platforms with physical memory starting at 0x0 the pfn
+ * could be 0 so we ensure that the handle will never be 0 by adjusting the
+ * encoded obj_idx value before encoding.
+ */
+static void *obj_location_to_handle(struct page *page, unsigned long obj_idx)
+{
+ unsigned long handle;
+
+ if (!page) {
+ BUG_ON(obj_idx);
+ return NULL;
+ }
+
+ handle = page_to_pfn(page) << OBJ_INDEX_BITS;
+ handle |= ((obj_idx + 1) & OBJ_INDEX_MASK);
+
+ return (void *)handle;
+}
+
+/*
+ * Decode <page, obj_idx> pair from the given object handle. We adjust the
+ * decoded obj_idx back to its original value since it was adjusted in
+ * obj_location_to_handle().
+ */
+static void obj_handle_to_location(unsigned long handle, struct page **page,
+ unsigned long *obj_idx)
+{
+ *page = pfn_to_page(handle >> OBJ_INDEX_BITS);
+ *obj_idx = (handle & OBJ_INDEX_MASK) - 1;
+}
+
+static unsigned long obj_idx_to_offset(struct page *page,
+ unsigned long obj_idx, int class_size)
+{
+ unsigned long off = 0;
+
+ if (!is_first_page(page))
+ off = page->index;
+
+ return off + obj_idx * class_size;
+}
+
+static void reset_page(struct page *page)
+{
+ clear_bit(PG_private, &page->flags);
+ clear_bit(PG_private_2, &page->flags);
+ set_page_private(page, 0);
+ page->mapping = NULL;
+ page->freelist = NULL;
+ page_mapcount_reset(page);
+}
+
+static void free_zspage(struct page *first_page)
+{
+ struct page *nextp, *tmp, *head_extra;
+
+ BUG_ON(!is_first_page(first_page));
+ BUG_ON(first_page->inuse);
+
+ head_extra = (struct page *)page_private(first_page);
+
+ reset_page(first_page);
+ __free_page(first_page);
+
+ /* zspage with only 1 system page */
+ if (!head_extra)
+ return;
+
+ list_for_each_entry_safe(nextp, tmp, &head_extra->lru, lru) {
+ list_del(&nextp->lru);
+ reset_page(nextp);
+ __free_page(nextp);
+ }
+ reset_page(head_extra);
+ __free_page(head_extra);
+}
+
+/* Initialize a newly allocated zspage */
+static void init_zspage(struct page *first_page, struct size_class *class)
+{
+ unsigned long off = 0;
+ struct page *page = first_page;
+
+ BUG_ON(!is_first_page(first_page));
+ while (page) {
+ struct page *next_page;
+ struct link_free *link;
+ unsigned int i, objs_on_page;
+
+ /*
+ * page->index stores offset of first object starting
+ * in the page. For the first page, this is always 0,
+ * so we use first_page->index (aka ->freelist) to store
+ * head of corresponding zspage's freelist.
+ */
+ if (page != first_page)
+ page->index = off;
+
+ link = (struct link_free *)kmap_atomic(page) +
+ off / sizeof(*link);
+ objs_on_page = (PAGE_SIZE - off) / class->size;
+
+ for (i = 1; i <= objs_on_page; i++) {
+ off += class->size;
+ if (off < PAGE_SIZE) {
+ link->next = obj_location_to_handle(page, i);
+ link += class->size / sizeof(*link);
+ }
+ }
+
+ /*
+ * We now come to the last (full or partial) object on this
+ * page, which must point to the first object on the next
+ * page (if present)
+ */
+ next_page = get_next_page(page);
+ link->next = obj_location_to_handle(next_page, 0);
+ kunmap_atomic(link);
+ page = next_page;
+ off = (off + class->size) % PAGE_SIZE;
+ }
+}
+
+/*
+ * Allocate a zspage for the given size class
+ */
+static struct page *alloc_zspage(struct size_class *class, gfp_t flags)
+{
+ int i, error;
+ struct page *first_page = NULL, *uninitialized_var(prev_page);
+
+ /*
+ * Allocate individual pages and link them together as:
+ * 1. first page->private = first sub-page
+ * 2. all sub-pages are linked together using page->lru
+ * 3. each sub-page is linked to the first page using page->first_page
+ *
+ * For each size class, First/Head pages are linked together using
+ * page->lru. Also, we set PG_private to identify the first page
+ * (i.e. no other sub-page has this flag set) and PG_private_2 to
+ * identify the last page.
+ */
+ error = -ENOMEM;
+ for (i = 0; i < class->pages_per_zspage; i++) {
+ struct page *page;
+
+ page = alloc_page(flags);
+ if (!page)
+ goto cleanup;
+
+ INIT_LIST_HEAD(&page->lru);
+ if (i == 0) { /* first page */
+ SetPagePrivate(page);
+ set_page_private(page, 0);
+ first_page = page;
+ first_page->inuse = 0;
+ }
+ if (i == 1)
+ set_page_private(first_page, (unsigned long)page);
+ if (i >= 1)
+ page->first_page = first_page;
+ if (i >= 2)
+ list_add(&page->lru, &prev_page->lru);
+ if (i == class->pages_per_zspage - 1) /* last page */
+ SetPagePrivate2(page);
+ prev_page = page;
+ }
+
+ init_zspage(first_page, class);
+
+ first_page->freelist = obj_location_to_handle(first_page, 0);
+ /* Maximum number of objects we can store in this zspage */
+ first_page->objects = class->pages_per_zspage * PAGE_SIZE / class->size;
+
+ error = 0; /* Success */
+
+cleanup:
+ if (unlikely(error) && first_page) {
+ free_zspage(first_page);
+ first_page = NULL;
+ }
+
+ return first_page;
+}
+
+static struct page *find_get_zspage(struct size_class *class)
+{
+ int i;
+ struct page *page;
+
+ for (i = 0; i < _ZS_NR_FULLNESS_GROUPS; i++) {
+ page = class->fullness_list[i];
+ if (page)
+ break;
+ }
+
+ return page;
+}
+
+#ifdef CONFIG_PGTABLE_MAPPING
+static inline int __zs_cpu_up(struct mapping_area *area)
+{
+ /*
+ * Make sure we don't leak memory if a cpu UP notification
+ * and zs_init() race and both call zs_cpu_up() on the same cpu
+ */
+ if (area->vm)
+ return 0;
+ area->vm = alloc_vm_area(PAGE_SIZE * 2, NULL);
+ if (!area->vm)
+ return -ENOMEM;
+ return 0;
+}
+
+static inline void __zs_cpu_down(struct mapping_area *area)
+{
+ if (area->vm)
+ free_vm_area(area->vm);
+ area->vm = NULL;
+}
+
+static inline void *__zs_map_object(struct mapping_area *area,
+ struct page *pages[2], int off, int size)
+{
+ BUG_ON(map_vm_area(area->vm, PAGE_KERNEL, &pages));
+ area->vm_addr = area->vm->addr;
+ return area->vm_addr + off;
+}
+
+static inline void __zs_unmap_object(struct mapping_area *area,
+ struct page *pages[2], int off, int size)
+{
+ unsigned long addr = (unsigned long)area->vm_addr;
+
+ unmap_kernel_range(addr, PAGE_SIZE * 2);
+}
+
+#else /* CONFIG_PGTABLE_MAPPING */
+
+static inline int __zs_cpu_up(struct mapping_area *area)
+{
+ /*
+ * Make sure we don't leak memory if a cpu UP notification
+ * and zs_init() race and both call zs_cpu_up() on the same cpu
+ */
+ if (area->vm_buf)
+ return 0;
+ area->vm_buf = (char *)__get_free_page(GFP_KERNEL);
+ if (!area->vm_buf)
+ return -ENOMEM;
+ return 0;
+}
+
+static inline void __zs_cpu_down(struct mapping_area *area)
+{
+ if (area->vm_buf)
+ free_page((unsigned long)area->vm_buf);
+ area->vm_buf = NULL;
+}
+
+static void *__zs_map_object(struct mapping_area *area,
+ struct page *pages[2], int off, int size)
+{
+ int sizes[2];
+ void *addr;
+ char *buf = area->vm_buf;
+
+ /* disable page faults to match kmap_atomic() return conditions */
+ pagefault_disable();
+
+ /* no read fastpath */
+ if (area->vm_mm == ZS_MM_WO)
+ goto out;
+
+ sizes[0] = PAGE_SIZE - off;
+ sizes[1] = size - sizes[0];
+
+ /* copy object to per-cpu buffer */
+ addr = kmap_atomic(pages[0]);
+ memcpy(buf, addr + off, sizes[0]);
+ kunmap_atomic(addr);
+ addr = kmap_atomic(pages[1]);
+ memcpy(buf + sizes[0], addr, sizes[1]);
+ kunmap_atomic(addr);
+out:
+ return area->vm_buf;
+}
+
+static void __zs_unmap_object(struct mapping_area *area,
+ struct page *pages[2], int off, int size)
+{
+ int sizes[2];
+ void *addr;
+ char *buf = area->vm_buf;
+
+ /* no write fastpath */
+ if (area->vm_mm == ZS_MM_RO)
+ goto out;
+
+ sizes[0] = PAGE_SIZE - off;
+ sizes[1] = size - sizes[0];
+
+ /* copy per-cpu buffer to object */
+ addr = kmap_atomic(pages[0]);
+ memcpy(addr + off, buf, sizes[0]);
+ kunmap_atomic(addr);
+ addr = kmap_atomic(pages[1]);
+ memcpy(addr, buf + sizes[0], sizes[1]);
+ kunmap_atomic(addr);
+
+out:
+ /* enable page faults to match kunmap_atomic() return conditions */
+ pagefault_enable();
+}
+
+#endif /* CONFIG_PGTABLE_MAPPING */
+
+static int zs_cpu_notifier(struct notifier_block *nb, unsigned long action,
+ void *pcpu)
+{
+ int ret, cpu = (long)pcpu;
+ struct mapping_area *area;
+
+ switch (action) {
+ case CPU_UP_PREPARE:
+ area = &per_cpu(zs_map_area, cpu);
+ ret = __zs_cpu_up(area);
+ if (ret)
+ return notifier_from_errno(ret);
+ break;
+ case CPU_DEAD:
+ case CPU_UP_CANCELED:
+ area = &per_cpu(zs_map_area, cpu);
+ __zs_cpu_down(area);
+ break;
+ }
+
+ return NOTIFY_OK;
+}
+
+static struct notifier_block zs_cpu_nb = {
+ .notifier_call = zs_cpu_notifier
+};
+
+static void zs_exit(void)
+{
+ int cpu;
+
+ for_each_online_cpu(cpu)
+ zs_cpu_notifier(NULL, CPU_DEAD, (void *)(long)cpu);
+ unregister_cpu_notifier(&zs_cpu_nb);
+}
+
+static int zs_init(void)
+{
+ int cpu, ret;
+
+ register_cpu_notifier(&zs_cpu_nb);
+ for_each_online_cpu(cpu) {
+ ret = zs_cpu_notifier(NULL, CPU_UP_PREPARE, (void *)(long)cpu);
+ if (notifier_to_errno(ret))
+ goto fail;
+ }
+ return 0;
+fail:
+ zs_exit();
+ return notifier_to_errno(ret);
+}
+
+/**
+ * zs_create_pool - Creates an allocation pool to work from.
+ * @flags: allocation flags used to allocate pool metadata
+ *
+ * This function must be called before anything when using
+ * the zsmalloc allocator.
+ *
+ * On success, a pointer to the newly created pool is returned,
+ * otherwise NULL.
+ */
+struct zs_pool *zs_create_pool(gfp_t flags)
+{
+ int i, ovhd_size;
+ struct zs_pool *pool;
+
+ ovhd_size = roundup(sizeof(*pool), PAGE_SIZE);
+ pool = kzalloc(ovhd_size, GFP_KERNEL);
+ if (!pool)
+ return NULL;
+
+ for (i = 0; i < ZS_SIZE_CLASSES; i++) {
+ int size;
+ struct size_class *class;
+
+ size = ZS_MIN_ALLOC_SIZE + i * ZS_SIZE_CLASS_DELTA;
+ if (size > ZS_MAX_ALLOC_SIZE)
+ size = ZS_MAX_ALLOC_SIZE;
+
+ class = &pool->size_class[i];
+ class->size = size;
+ class->index = i;
+ spin_lock_init(&class->lock);
+ class->pages_per_zspage = get_pages_per_zspage(size);
+
+ }
+
+ pool->flags = flags;
+
+ return pool;
+}
+EXPORT_SYMBOL_GPL(zs_create_pool);
+
+void zs_destroy_pool(struct zs_pool *pool)
+{
+ int i;
+
+ for (i = 0; i < ZS_SIZE_CLASSES; i++) {
+ int fg;
+ struct size_class *class = &pool->size_class[i];
+
+ for (fg = 0; fg < _ZS_NR_FULLNESS_GROUPS; fg++) {
+ if (class->fullness_list[fg]) {
+ pr_info("Freeing non-empty class with size %db, fullness group %d\n",
+ class->size, fg);
+ }
+ }
+ }
+ kfree(pool);
+}
+EXPORT_SYMBOL_GPL(zs_destroy_pool);
+
+/**
+ * zs_malloc - Allocate block of given size from pool.
+ * @pool: pool to allocate from
+ * @size: size of block to allocate
+ *
+ * On success, handle to the allocated object is returned,
+ * otherwise 0.
+ * Allocation requests with size > ZS_MAX_ALLOC_SIZE will fail.
+ */
+unsigned long zs_malloc(struct zs_pool *pool, size_t size)
+{
+ unsigned long obj;
+ struct link_free *link;
+ int class_idx;
+ struct size_class *class;
+
+ struct page *first_page, *m_page;
+ unsigned long m_objidx, m_offset;
+
+ if (unlikely(!size || size > ZS_MAX_ALLOC_SIZE))
+ return 0;
+
+ class_idx = get_size_class_index(size);
+ class = &pool->size_class[class_idx];
+ BUG_ON(class_idx != class->index);
+
+ spin_lock(&class->lock);
+ first_page = find_get_zspage(class);
+
+ if (!first_page) {
+ spin_unlock(&class->lock);
+ first_page = alloc_zspage(class, pool->flags);
+ if (unlikely(!first_page))
+ return 0;
+
+ set_zspage_mapping(first_page, class->index, ZS_EMPTY);
+ spin_lock(&class->lock);
+ class->pages_allocated += class->pages_per_zspage;
+ }
+
+ obj = (unsigned long)first_page->freelist;
+ obj_handle_to_location(obj, &m_page, &m_objidx);
+ m_offset = obj_idx_to_offset(m_page, m_objidx, class->size);
+
+ link = (struct link_free *)kmap_atomic(m_page) +
+ m_offset / sizeof(*link);
+ first_page->freelist = link->next;
+ memset(link, POISON_INUSE, sizeof(*link));
+ kunmap_atomic(link);
+
+ first_page->inuse++;
+ /* Now move the zspage to another fullness group, if required */
+ fix_fullness_group(pool, first_page);
+ spin_unlock(&class->lock);
+
+ return obj;
+}
+EXPORT_SYMBOL_GPL(zs_malloc);
+
+void zs_free(struct zs_pool *pool, unsigned long obj)
+{
+ struct link_free *link;
+ struct page *first_page, *f_page;
+ unsigned long f_objidx, f_offset;
+
+ int class_idx;
+ struct size_class *class;
+ enum fullness_group fullness;
+
+ if (unlikely(!obj))
+ return;
+
+ obj_handle_to_location(obj, &f_page, &f_objidx);
+ first_page = get_first_page(f_page);
+
+ get_zspage_mapping(first_page, &class_idx, &fullness);
+ class = &pool->size_class[class_idx];
+ f_offset = obj_idx_to_offset(f_page, f_objidx, class->size);
+
+ spin_lock(&class->lock);
+
+ /* Insert this object in containing zspage's freelist */
+ link = (struct link_free *)((unsigned char *)kmap_atomic(f_page)
+ + f_offset);
+ link->next = first_page->freelist;
+ kunmap_atomic(link);
+ first_page->freelist = (void *)obj;
+
+ first_page->inuse--;
+ fullness = fix_fullness_group(pool, first_page);
+
+ if (fullness == ZS_EMPTY)
+ class->pages_allocated -= class->pages_per_zspage;
+
+ spin_unlock(&class->lock);
+
+ if (fullness == ZS_EMPTY)
+ free_zspage(first_page);
+}
+EXPORT_SYMBOL_GPL(zs_free);
+
+/**
+ * zs_map_object - get address of allocated object from handle.
+ * @pool: pool from which the object was allocated
+ * @handle: handle returned from zs_malloc
+ *
+ * Before using an object allocated from zs_malloc, it must be mapped using
+ * this function. When done with the object, it must be unmapped using
+ * zs_unmap_object.
+ *
+ * Only one object can be mapped per cpu at a time. There is no protection
+ * against nested mappings.
+ *
+ * This function returns with preemption and page faults disabled.
+ */
+void *zs_map_object(struct zs_pool *pool, unsigned long handle,
+ enum zs_mapmode mm)
+{
+ struct page *page;
+ unsigned long obj_idx, off;
+
+ unsigned int class_idx;
+ enum fullness_group fg;
+ struct size_class *class;
+ struct mapping_area *area;
+ struct page *pages[2];
+
+ BUG_ON(!handle);
+
+ /*
+ * Because we use per-cpu mapping areas shared among the
+ * pools/users, we can't allow mapping in interrupt context
+ * because it can corrupt another users mappings.
+ */
+ BUG_ON(in_interrupt());
+
+ obj_handle_to_location(handle, &page, &obj_idx);
+ get_zspage_mapping(get_first_page(page), &class_idx, &fg);
+ class = &pool->size_class[class_idx];
+ off = obj_idx_to_offset(page, obj_idx, class->size);
+
+ area = &get_cpu_var(zs_map_area);
+ area->vm_mm = mm;
+ if (off + class->size <= PAGE_SIZE) {
+ /* this object is contained entirely within a page */
+ area->vm_addr = kmap_atomic(page);
+ return area->vm_addr + off;
+ }
+
+ /* this object spans two pages */
+ pages[0] = page;
+ pages[1] = get_next_page(page);
+ BUG_ON(!pages[1]);
+
+ return __zs_map_object(area, pages, off, class->size);
+}
+EXPORT_SYMBOL_GPL(zs_map_object);
+
+void zs_unmap_object(struct zs_pool *pool, unsigned long handle)
+{
+ struct page *page;
+ unsigned long obj_idx, off;
+
+ unsigned int class_idx;
+ enum fullness_group fg;
+ struct size_class *class;
+ struct mapping_area *area;
+
+ BUG_ON(!handle);
+
+ obj_handle_to_location(handle, &page, &obj_idx);
+ get_zspage_mapping(get_first_page(page), &class_idx, &fg);
+ class = &pool->size_class[class_idx];
+ off = obj_idx_to_offset(page, obj_idx, class->size);
+
+ area = &__get_cpu_var(zs_map_area);
+ if (off + class->size <= PAGE_SIZE)
+ kunmap_atomic(area->vm_addr);
+ else {
+ struct page *pages[2];
+
+ pages[0] = page;
+ pages[1] = get_next_page(page);
+ BUG_ON(!pages[1]);
+
+ __zs_unmap_object(area, pages, off, class->size);
+ }
+ put_cpu_var(zs_map_area);
+}
+EXPORT_SYMBOL_GPL(zs_unmap_object);
+
+u64 zs_get_total_size_bytes(struct zs_pool *pool)
+{
+ int i;
+ u64 npages = 0;
+
+ for (i = 0; i < ZS_SIZE_CLASSES; i++)
+ npages += pool->size_class[i].pages_allocated;
+
+ return npages << PAGE_SHIFT;
+}
+EXPORT_SYMBOL_GPL(zs_get_total_size_bytes);
+
+module_init(zs_init);
+module_exit(zs_exit);
+
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_AUTHOR("Nitin Gupta <ngupta@vflare.org>");
generated by cgit (git 2.34.1) at 2025-04-18 07:04:27 +0000