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-rw-r--r--mm/Kconfig12
-rw-r--r--mm/backing-dev.c5
-rw-r--r--mm/bootmem.c39
-rw-r--r--mm/huge_memory.c2
-rw-r--r--mm/hugetlb.c4
-rw-r--r--mm/memcontrol.c97
-rw-r--r--mm/memory-failure.c22
-rw-r--r--mm/memory.c13
-rw-r--r--mm/memory_hotplug.c48
-rw-r--r--mm/mm_init.c47
-rw-r--r--mm/mmap.c2
-rw-r--r--mm/mremap.c2
-rw-r--r--mm/nobootmem.c35
-rw-r--r--mm/nommu.c6
-rw-r--r--mm/page_alloc.c294
-rw-r--r--mm/page_io.c50
-rw-r--r--mm/rmap.c7
-rw-r--r--mm/sparse.c3
-rw-r--r--mm/swap.c106
-rw-r--r--mm/swapfile.c55
-rw-r--r--mm/vmalloc.c103
-rw-r--r--mm/vmscan.c585
22 files changed, 1021 insertions, 516 deletions
diff --git a/mm/Kconfig b/mm/Kconfig
index f5e698e30d4a..7e28ecfa8aa4 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -477,3 +477,15 @@ config FRONTSWAP
and swap data is stored as normal on the matching swap device.
If unsure, say Y to enable frontswap.
+
+config MEM_SOFT_DIRTY
+ bool "Track memory changes"
+ depends on CHECKPOINT_RESTORE && HAVE_ARCH_SOFT_DIRTY
+ select PROC_PAGE_MONITOR
+ help
+ This option enables memory changes tracking by introducing a
+ soft-dirty bit on pte-s. This bit it set when someone writes
+ into a page just as regular dirty bit, but unlike the latter
+ it can be cleared by hands.
+
+ See Documentation/vm/soft-dirty.txt for more details.
diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index 502517492258..d014ee5fcbbd 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -515,7 +515,6 @@ EXPORT_SYMBOL(bdi_destroy);
int bdi_setup_and_register(struct backing_dev_info *bdi, char *name,
unsigned int cap)
{
- char tmp[32];
int err;
bdi->name = name;
@@ -524,8 +523,8 @@ int bdi_setup_and_register(struct backing_dev_info *bdi, char *name,
if (err)
return err;
- sprintf(tmp, "%.28s%s", name, "-%d");
- err = bdi_register(bdi, NULL, tmp, atomic_long_inc_return(&bdi_seq));
+ err = bdi_register(bdi, NULL, "%.28s-%ld", name,
+ atomic_long_inc_return(&bdi_seq));
if (err) {
bdi_destroy(bdi);
return err;
diff --git a/mm/bootmem.c b/mm/bootmem.c
index 2b0bcb019ec2..6ab7744e692e 100644
--- a/mm/bootmem.c
+++ b/mm/bootmem.c
@@ -241,33 +241,26 @@ static unsigned long __init free_all_bootmem_core(bootmem_data_t *bdata)
return count;
}
-static void reset_node_lowmem_managed_pages(pg_data_t *pgdat)
+static int reset_managed_pages_done __initdata;
+
+static inline void __init reset_node_managed_pages(pg_data_t *pgdat)
{
struct zone *z;
- /*
- * In free_area_init_core(), highmem zone's managed_pages is set to
- * present_pages, and bootmem allocator doesn't allocate from highmem
- * zones. So there's no need to recalculate managed_pages because all
- * highmem pages will be managed by the buddy system. Here highmem
- * zone also includes highmem movable zone.
- */
+ if (reset_managed_pages_done)
+ return;
+
for (z = pgdat->node_zones; z < pgdat->node_zones + MAX_NR_ZONES; z++)
- if (!is_highmem(z))
- z->managed_pages = 0;
+ z->managed_pages = 0;
}
-/**
- * free_all_bootmem_node - release a node's free pages to the buddy allocator
- * @pgdat: node to be released
- *
- * Returns the number of pages actually released.
- */
-unsigned long __init free_all_bootmem_node(pg_data_t *pgdat)
+void __init reset_all_zones_managed_pages(void)
{
- register_page_bootmem_info_node(pgdat);
- reset_node_lowmem_managed_pages(pgdat);
- return free_all_bootmem_core(pgdat->bdata);
+ struct pglist_data *pgdat;
+
+ for_each_online_pgdat(pgdat)
+ reset_node_managed_pages(pgdat);
+ reset_managed_pages_done = 1;
}
/**
@@ -279,14 +272,14 @@ unsigned long __init free_all_bootmem(void)
{
unsigned long total_pages = 0;
bootmem_data_t *bdata;
- struct pglist_data *pgdat;
- for_each_online_pgdat(pgdat)
- reset_node_lowmem_managed_pages(pgdat);
+ reset_all_zones_managed_pages();
list_for_each_entry(bdata, &bdata_list, list)
total_pages += free_all_bootmem_core(bdata);
+ totalram_pages += total_pages;
+
return total_pages;
}
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 362c329b83fe..d8b3b850150c 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1429,7 +1429,7 @@ int move_huge_pmd(struct vm_area_struct *vma, struct vm_area_struct *new_vma,
if (ret == 1) {
pmd = pmdp_get_and_clear(mm, old_addr, old_pmd);
VM_BUG_ON(!pmd_none(*new_pmd));
- set_pmd_at(mm, new_addr, new_pmd, pmd);
+ set_pmd_at(mm, new_addr, new_pmd, pmd_mksoft_dirty(pmd));
spin_unlock(&mm->page_table_lock);
}
out:
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index aed085ad11a8..83aff0a4d093 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -319,7 +319,7 @@ unsigned long vma_kernel_pagesize(struct vm_area_struct *vma)
hstate = hstate_vma(vma);
- return 1UL << (hstate->order + PAGE_SHIFT);
+ return 1UL << huge_page_shift(hstate);
}
EXPORT_SYMBOL_GPL(vma_kernel_pagesize);
@@ -1263,7 +1263,7 @@ static void __init gather_bootmem_prealloc(void)
* side-effects, like CommitLimit going negative.
*/
if (h->order > (MAX_ORDER - 1))
- totalram_pages += 1 << h->order;
+ adjust_managed_page_count(page, 1 << h->order);
}
}
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 194721839cf5..2e851f453814 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1148,6 +1148,58 @@ skip_node:
return NULL;
}
+static void mem_cgroup_iter_invalidate(struct mem_cgroup *root)
+{
+ /*
+ * When a group in the hierarchy below root is destroyed, the
+ * hierarchy iterator can no longer be trusted since it might
+ * have pointed to the destroyed group. Invalidate it.
+ */
+ atomic_inc(&root->dead_count);
+}
+
+static struct mem_cgroup *
+mem_cgroup_iter_load(struct mem_cgroup_reclaim_iter *iter,
+ struct mem_cgroup *root,
+ int *sequence)
+{
+ struct mem_cgroup *position = NULL;
+ /*
+ * A cgroup destruction happens in two stages: offlining and
+ * release. They are separated by a RCU grace period.
+ *
+ * If the iterator is valid, we may still race with an
+ * offlining. The RCU lock ensures the object won't be
+ * released, tryget will fail if we lost the race.
+ */
+ *sequence = atomic_read(&root->dead_count);
+ if (iter->last_dead_count == *sequence) {
+ smp_rmb();
+ position = iter->last_visited;
+ if (position && !css_tryget(&position->css))
+ position = NULL;
+ }
+ return position;
+}
+
+static void mem_cgroup_iter_update(struct mem_cgroup_reclaim_iter *iter,
+ struct mem_cgroup *last_visited,
+ struct mem_cgroup *new_position,
+ int sequence)
+{
+ if (last_visited)
+ css_put(&last_visited->css);
+ /*
+ * We store the sequence count from the time @last_visited was
+ * loaded successfully instead of rereading it here so that we
+ * don't lose destruction events in between. We could have
+ * raced with the destruction of @new_position after all.
+ */
+ iter->last_visited = new_position;
+ smp_wmb();
+ iter->last_dead_count = sequence;
+}
+
/**
* mem_cgroup_iter - iterate over memory cgroup hierarchy
* @root: hierarchy root
@@ -1171,7 +1223,6 @@ struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root,
{
struct mem_cgroup *memcg = NULL;
struct mem_cgroup *last_visited = NULL;
- unsigned long uninitialized_var(dead_count);
if (mem_cgroup_disabled())
return NULL;
@@ -1191,6 +1242,7 @@ struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root,
rcu_read_lock();
while (!memcg) {
struct mem_cgroup_reclaim_iter *uninitialized_var(iter);
+ int uninitialized_var(seq);
if (reclaim) {
int nid = zone_to_nid(reclaim->zone);
@@ -1204,37 +1256,13 @@ struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root,
goto out_unlock;
}
- /*
- * If the dead_count mismatches, a destruction
- * has happened or is happening concurrently.
- * If the dead_count matches, a destruction
- * might still happen concurrently, but since
- * we checked under RCU, that destruction
- * won't free the object until we release the
- * RCU reader lock. Thus, the dead_count
- * check verifies the pointer is still valid,
- * css_tryget() verifies the cgroup pointed to
- * is alive.
- */
- dead_count = atomic_read(&root->dead_count);
- if (dead_count == iter->last_dead_count) {
- smp_rmb();
- last_visited = iter->last_visited;
- if (last_visited &&
- !css_tryget(&last_visited->css))
- last_visited = NULL;
- }
+ last_visited = mem_cgroup_iter_load(iter, root, &seq);
}
memcg = __mem_cgroup_iter_next(root, last_visited);
if (reclaim) {
- if (last_visited)
- css_put(&last_visited->css);
-
- iter->last_visited = memcg;
- smp_wmb();
- iter->last_dead_count = dead_count;
+ mem_cgroup_iter_update(iter, last_visited, memcg, seq);
if (!memcg)
iter->generation++;
@@ -1448,11 +1476,12 @@ static bool mem_cgroup_same_or_subtree(const struct mem_cgroup *root_memcg,
return ret;
}
-int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *memcg)
+bool task_in_mem_cgroup(struct task_struct *task,
+ const struct mem_cgroup *memcg)
{
- int ret;
struct mem_cgroup *curr = NULL;
struct task_struct *p;
+ bool ret;
p = find_lock_task_mm(task);
if (p) {
@@ -1464,14 +1493,14 @@ int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *memcg)
* killer still needs to detect if they have already been oom
* killed to prevent needlessly killing additional tasks.
*/
- task_lock(task);
+ rcu_read_lock();
curr = mem_cgroup_from_task(task);
if (curr)
css_get(&curr->css);
- task_unlock(task);
+ rcu_read_unlock();
}
if (!curr)
- return 0;
+ return false;
/*
* We should check use_hierarchy of "memcg" not "curr". Because checking
* use_hierarchy of "curr" here make this function true if hierarchy is
@@ -6317,14 +6346,14 @@ static void mem_cgroup_invalidate_reclaim_iterators(struct mem_cgroup *memcg)
struct mem_cgroup *parent = memcg;
while ((parent = parent_mem_cgroup(parent)))
- atomic_inc(&parent->dead_count);
+ mem_cgroup_iter_invalidate(parent);
/*
* if the root memcg is not hierarchical we have to check it
* explicitely.
*/
if (!root_mem_cgroup->use_hierarchy)
- atomic_inc(&root_mem_cgroup->dead_count);
+ mem_cgroup_iter_invalidate(root_mem_cgroup);
}
static void mem_cgroup_css_offline(struct cgroup *cont)
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index ceb0c7f1932f..2c13aa7a0164 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1410,7 +1410,8 @@ static int __get_any_page(struct page *p, unsigned long pfn, int flags)
/*
* Isolate the page, so that it doesn't get reallocated if it
- * was free.
+ * was free. This flag should be kept set until the source page
+ * is freed and PG_hwpoison on it is set.
*/
set_migratetype_isolate(p, true);
/*
@@ -1433,7 +1434,6 @@ static int __get_any_page(struct page *p, unsigned long pfn, int flags)
/* Not a free page */
ret = 1;
}
- unset_migratetype_isolate(p, MIGRATE_MOVABLE);
unlock_memory_hotplug();
return ret;
}
@@ -1494,7 +1494,6 @@ static int soft_offline_huge_page(struct page *page, int flags)
atomic_long_add(1 << compound_trans_order(hpage),
&num_poisoned_pages);
}
- /* keep elevated page count for bad page */
return ret;
}
@@ -1559,7 +1558,7 @@ int soft_offline_page(struct page *page, int flags)
atomic_long_inc(&num_poisoned_pages);
}
}
- /* keep elevated page count for bad page */
+ unset_migratetype_isolate(page, MIGRATE_MOVABLE);
return ret;
}
@@ -1625,7 +1624,22 @@ static int __soft_offline_page(struct page *page, int flags)
if (ret > 0)
ret = -EIO;
} else {
+ /*
+ * After page migration succeeds, the source page can
+ * be trapped in pagevec and actual freeing is delayed.
+ * Freeing code works differently based on PG_hwpoison,
+ * so there's a race. We need to make sure that the
+ * source page should be freed back to buddy before
+ * setting PG_hwpoison.
+ */
+ if (!is_free_buddy_page(page))
+ lru_add_drain_all();
+ if (!is_free_buddy_page(page))
+ drain_all_pages();
SetPageHWPoison(page);
+ if (!is_free_buddy_page(page))
+ pr_info("soft offline: %#lx: page leaked\n",
+ pfn);
atomic_long_inc(&num_poisoned_pages);
}
} else {
diff --git a/mm/memory.c b/mm/memory.c
index 95d0cce63583..b68812d682b6 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -82,7 +82,6 @@ EXPORT_SYMBOL(max_mapnr);
EXPORT_SYMBOL(mem_map);
#endif
-unsigned long num_physpages;
/*
* A number of key systems in x86 including ioremap() rely on the assumption
* that high_memory defines the upper bound on direct map memory, then end
@@ -92,7 +91,6 @@ unsigned long num_physpages;
*/
void * high_memory;
-EXPORT_SYMBOL(num_physpages);
EXPORT_SYMBOL(high_memory);
/*
@@ -1101,6 +1099,7 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb,
spinlock_t *ptl;
pte_t *start_pte;
pte_t *pte;
+ unsigned long range_start = addr;
again:
init_rss_vec(rss);
@@ -1206,12 +1205,14 @@ again:
force_flush = 0;
#ifdef HAVE_GENERIC_MMU_GATHER
- tlb->start = addr;
- tlb->end = end;
+ tlb->start = range_start;
+ tlb->end = addr;
#endif
tlb_flush_mmu(tlb);
- if (addr != end)
+ if (addr != end) {
+ range_start = addr;
goto again;
+ }
}
return addr;
@@ -2904,7 +2905,7 @@ static inline void unmap_mapping_range_tree(struct rb_root *root,
details->first_index, details->last_index) {
vba = vma->vm_pgoff;
- vea = vba + ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) - 1;
+ vea = vba + vma_pages(vma) - 1;
/* Assume for now that PAGE_CACHE_SHIFT == PAGE_SHIFT */
zba = details->first_index;
if (zba < vba)
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 081b4d654ed6..f5ba127b2051 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -75,7 +75,7 @@ static struct resource *register_memory_resource(u64 start, u64 size)
res->end = start + size - 1;
res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
if (request_resource(&iomem_resource, res) < 0) {
- printk("System RAM resource %pR cannot be added\n", res);
+ pr_debug("System RAM resource %pR cannot be added\n", res);
kfree(res);
res = NULL;
}
@@ -101,12 +101,9 @@ void get_page_bootmem(unsigned long info, struct page *page,
atomic_inc(&page->_count);
}
-/* reference to __meminit __free_pages_bootmem is valid
- * so use __ref to tell modpost not to generate a warning */
-void __ref put_page_bootmem(struct page *page)
+void put_page_bootmem(struct page *page)
{
unsigned long type;
- static DEFINE_MUTEX(ppb_lock);
type = (unsigned long) page->lru.next;
BUG_ON(type < MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE ||
@@ -116,17 +113,8 @@ void __ref put_page_bootmem(struct page *page)
ClearPagePrivate(page);
set_page_private(page, 0);
INIT_LIST_HEAD(&page->lru);
-
- /*
- * Please refer to comment for __free_pages_bootmem()
- * for why we serialize here.
- */
- mutex_lock(&ppb_lock);
- __free_pages_bootmem(page, 0);
- mutex_unlock(&ppb_lock);
- totalram_pages++;
+ free_reserved_page(page);
}
-
}
#ifdef CONFIG_HAVE_BOOTMEM_INFO_NODE
@@ -309,7 +297,7 @@ static int __meminit move_pfn_range_left(struct zone *z1, struct zone *z2,
/* can't move pfns which are higher than @z2 */
if (end_pfn > zone_end_pfn(z2))
goto out_fail;
- /* the move out part mast at the left most of @z2 */
+ /* the move out part must be at the left most of @z2 */
if (start_pfn > z2->zone_start_pfn)
goto out_fail;
/* must included/overlap */
@@ -775,29 +763,18 @@ EXPORT_SYMBOL_GPL(restore_online_page_callback);
void __online_page_set_limits(struct page *page)
{
- unsigned long pfn = page_to_pfn(page);
-
- if (pfn >= num_physpages)
- num_physpages = pfn + 1;
}
EXPORT_SYMBOL_GPL(__online_page_set_limits);
void __online_page_increment_counters(struct page *page)
{
- totalram_pages++;
-
-#ifdef CONFIG_HIGHMEM
- if (PageHighMem(page))
- totalhigh_pages++;
-#endif
+ adjust_managed_page_count(page, 1);
}
EXPORT_SYMBOL_GPL(__online_page_increment_counters);
void __online_page_free(struct page *page)
{
- ClearPageReserved(page);
- init_page_count(page);
- __free_page(page);
+ __free_reserved_page(page);
}
EXPORT_SYMBOL_GPL(__online_page_free);
@@ -918,6 +895,7 @@ static void node_states_set_node(int node, struct memory_notify *arg)
int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_type)
{
+ unsigned long flags;
unsigned long onlined_pages = 0;
struct zone *zone;
int need_zonelists_rebuild = 0;
@@ -994,9 +972,12 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_typ
return ret;
}
- zone->managed_pages += onlined_pages;
zone->present_pages += onlined_pages;
+
+ pgdat_resize_lock(zone->zone_pgdat, &flags);
zone->zone_pgdat->node_present_pages += onlined_pages;
+ pgdat_resize_unlock(zone->zone_pgdat, &flags);
+
if (onlined_pages) {
node_states_set_node(zone_to_nid(zone), &arg);
if (need_zonelists_rebuild)
@@ -1487,6 +1468,7 @@ static int __ref __offline_pages(unsigned long start_pfn,
unsigned long pfn, nr_pages, expire;
long offlined_pages;
int ret, drain, retry_max, node;
+ unsigned long flags;
struct zone *zone;
struct memory_notify arg;
@@ -1578,10 +1560,12 @@ repeat:
/* reset pagetype flags and makes migrate type to be MOVABLE */
undo_isolate_page_range(start_pfn, end_pfn, MIGRATE_MOVABLE);
/* removal success */
- zone->managed_pages -= offlined_pages;
+ adjust_managed_page_count(pfn_to_page(start_pfn), -offlined_pages);
zone->present_pages -= offlined_pages;
+
+ pgdat_resize_lock(zone->zone_pgdat, &flags);
zone->zone_pgdat->node_present_pages -= offlined_pages;
- totalram_pages -= offlined_pages;
+ pgdat_resize_unlock(zone->zone_pgdat, &flags);
init_per_zone_wmark_min();
diff --git a/mm/mm_init.c b/mm/mm_init.c
index c280a02ea11e..633c08863fd8 100644
--- a/mm/mm_init.c
+++ b/mm/mm_init.c
@@ -9,6 +9,8 @@
#include <linux/init.h>
#include <linux/kobject.h>
#include <linux/export.h>
+#include <linux/memory.h>
+#include <linux/notifier.h>
#include "internal.h"
#ifdef CONFIG_DEBUG_MEMORY_INIT
@@ -147,6 +149,51 @@ early_param("mminit_loglevel", set_mminit_loglevel);
struct kobject *mm_kobj;
EXPORT_SYMBOL_GPL(mm_kobj);
+#ifdef CONFIG_SMP
+s32 vm_committed_as_batch = 32;
+
+static void __meminit mm_compute_batch(void)
+{
+ u64 memsized_batch;
+ s32 nr = num_present_cpus();
+ s32 batch = max_t(s32, nr*2, 32);
+
+ /* batch size set to 0.4% of (total memory/#cpus), or max int32 */
+ memsized_batch = min_t(u64, (totalram_pages/nr)/256, 0x7fffffff);
+
+ vm_committed_as_batch = max_t(s32, memsized_batch, batch);
+}
+
+static int __meminit mm_compute_batch_notifier(struct notifier_block *self,
+ unsigned long action, void *arg)
+{
+ switch (action) {
+ case MEM_ONLINE:
+ case MEM_OFFLINE:
+ mm_compute_batch();
+ default:
+ break;
+ }
+ return NOTIFY_OK;
+}
+
+static struct notifier_block compute_batch_nb __meminitdata = {
+ .notifier_call = mm_compute_batch_notifier,
+ .priority = IPC_CALLBACK_PRI, /* use lowest priority */
+};
+
+static int __init mm_compute_batch_init(void)
+{
+ mm_compute_batch();
+ register_hotmemory_notifier(&compute_batch_nb);
+
+ return 0;
+}
+
+__initcall(mm_compute_batch_init);
+
+#endif
+
static int __init mm_sysfs_init(void)
{
mm_kobj = kobject_create_and_add("mm", kernel_kobj);
diff --git a/mm/mmap.c b/mm/mmap.c
index f681e1842fad..8468ffd05bae 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -955,7 +955,7 @@ can_vma_merge_after(struct vm_area_struct *vma, unsigned long vm_flags,
if (is_mergeable_vma(vma, file, vm_flags) &&
is_mergeable_anon_vma(anon_vma, vma->anon_vma, vma)) {
pgoff_t vm_pglen;
- vm_pglen = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
+ vm_pglen = vma_pages(vma);
if (vma->vm_pgoff + vm_pglen == vm_pgoff)
return 1;
}
diff --git a/mm/mremap.c b/mm/mremap.c
index 463a25705ac6..3708655378e9 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -126,7 +126,7 @@ static void move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd,
continue;
pte = ptep_get_and_clear(mm, old_addr, old_pte);
pte = move_pte(pte, new_vma->vm_page_prot, old_addr, new_addr);
- set_pte_at(mm, new_addr, new_pte, pte);
+ set_pte_at(mm, new_addr, new_pte, pte_mksoft_dirty(pte));
}
arch_leave_lazy_mmu_mode();
diff --git a/mm/nobootmem.c b/mm/nobootmem.c
index bdd3fa2fc73b..61107cf55bb3 100644
--- a/mm/nobootmem.c
+++ b/mm/nobootmem.c
@@ -137,20 +137,25 @@ static unsigned long __init free_low_memory_core_early(void)
return count;
}
-static void reset_node_lowmem_managed_pages(pg_data_t *pgdat)
+static int reset_managed_pages_done __initdata;
+
+static inline void __init reset_node_managed_pages(pg_data_t *pgdat)
{
struct zone *z;
- /*
- * In free_area_init_core(), highmem zone's managed_pages is set to
- * present_pages, and bootmem allocator doesn't allocate from highmem
- * zones. So there's no need to recalculate managed_pages because all
- * highmem pages will be managed by the buddy system. Here highmem
- * zone also includes highmem movable zone.
- */
+ if (reset_managed_pages_done)
+ return;
for (z = pgdat->node_zones; z < pgdat->node_zones + MAX_NR_ZONES; z++)
- if (!is_highmem(z))
- z->managed_pages = 0;
+ z->managed_pages = 0;
+}
+
+void __init reset_all_zones_managed_pages(void)
+{
+ struct pglist_data *pgdat;
+
+ for_each_online_pgdat(pgdat)
+ reset_node_managed_pages(pgdat);
+ reset_managed_pages_done = 1;
}
/**
@@ -160,17 +165,19 @@ static void reset_node_lowmem_managed_pages(pg_data_t *pgdat)
*/
unsigned long __init free_all_bootmem(void)
{
- struct pglist_data *pgdat;
+ unsigned long pages;
- for_each_online_pgdat(pgdat)
- reset_node_lowmem_managed_pages(pgdat);
+ reset_all_zones_managed_pages();
/*
* We need to use MAX_NUMNODES instead of NODE_DATA(0)->node_id
* because in some case like Node0 doesn't have RAM installed
* low ram will be on Node1
*/
- return free_low_memory_core_early();
+ pages = free_low_memory_core_early();
+ totalram_pages += pages;
+
+ return pages;
}
/**
diff --git a/mm/nommu.c b/mm/nommu.c
index 298884dcd6e7..e44e6e0a125c 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -56,7 +56,6 @@
void *high_memory;
struct page *mem_map;
unsigned long max_mapnr;
-unsigned long num_physpages;
unsigned long highest_memmap_pfn;
struct percpu_counter vm_committed_as;
int sysctl_overcommit_memory = OVERCOMMIT_GUESS; /* heuristic overcommit */
@@ -85,7 +84,6 @@ unsigned long vm_memory_committed(void)
EXPORT_SYMBOL_GPL(vm_memory_committed);
EXPORT_SYMBOL(mem_map);
-EXPORT_SYMBOL(num_physpages);
/* list of mapped, potentially shareable regions */
static struct kmem_cache *vm_region_jar;
@@ -282,6 +280,10 @@ EXPORT_SYMBOL(vmalloc_to_pfn);
long vread(char *buf, char *addr, unsigned long count)
{
+ /* Don't allow overflow */
+ if ((unsigned long) buf + count < count)
+ count = -(unsigned long) buf;
+
memcpy(buf, addr, count);
return count;
}
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index c3edb624fccf..327516b7aee9 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -61,10 +61,14 @@
#include <linux/hugetlb.h>
#include <linux/sched/rt.h>
+#include <asm/sections.h>
#include <asm/tlbflush.h>
#include <asm/div64.h>
#include "internal.h"
+/* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */
+static DEFINE_MUTEX(pcp_batch_high_lock);
+
#ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
DEFINE_PER_CPU(int, numa_node);
EXPORT_PER_CPU_SYMBOL(numa_node);
@@ -100,6 +104,9 @@ nodemask_t node_states[NR_NODE_STATES] __read_mostly = {
};
EXPORT_SYMBOL(node_states);
+/* Protect totalram_pages and zone->managed_pages */
+static DEFINE_SPINLOCK(managed_page_count_lock);
+
unsigned long totalram_pages __read_mostly;
unsigned long totalreserve_pages __read_mostly;
/*
@@ -739,14 +746,7 @@ static void __free_pages_ok(struct page *page, unsigned int order)
local_irq_restore(flags);
}
-/*
- * Read access to zone->managed_pages is safe because it's unsigned long,
- * but we still need to serialize writers. Currently all callers of
- * __free_pages_bootmem() except put_page_bootmem() should only be used
- * at boot time. So for shorter boot time, we shift the burden to
- * put_page_bootmem() to serialize writers.
- */
-void __meminit __free_pages_bootmem(struct page *page, unsigned int order)
+void __init __free_pages_bootmem(struct page *page, unsigned int order)
{
unsigned int nr_pages = 1 << order;
unsigned int loop;
@@ -781,11 +781,7 @@ void __init init_cma_reserved_pageblock(struct page *page)
set_page_refcounted(page);
set_pageblock_migratetype(page, MIGRATE_CMA);
__free_pages(page, pageblock_order);
- totalram_pages += pageblock_nr_pages;
-#ifdef CONFIG_HIGHMEM
- if (PageHighMem(page))
- totalhigh_pages += pageblock_nr_pages;
-#endif
+ adjust_managed_page_count(page, pageblock_nr_pages);
}
#endif
@@ -1179,10 +1175,12 @@ void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
{
unsigned long flags;
int to_drain;
+ unsigned long batch;
local_irq_save(flags);
- if (pcp->count >= pcp->batch)
- to_drain = pcp->batch;
+ batch = ACCESS_ONCE(pcp->batch);
+ if (pcp->count >= batch)
+ to_drain = batch;
else
to_drain = pcp->count;
if (to_drain > 0) {
@@ -1350,8 +1348,9 @@ void free_hot_cold_page(struct page *page, int cold)
list_add(&page->lru, &pcp->lists[migratetype]);
pcp->count++;
if (pcp->count >= pcp->high) {
- free_pcppages_bulk(zone, pcp->batch, pcp);
- pcp->count -= pcp->batch;
+ unsigned long batch = ACCESS_ONCE(pcp->batch);
+ free_pcppages_bulk(zone, batch, pcp);
+ pcp->count -= batch;
}
out:
@@ -2839,7 +2838,7 @@ EXPORT_SYMBOL(free_pages_exact);
* nr_free_zone_pages() counts the number of counts pages which are beyond the
* high watermark within all zones at or below a given zone index. For each
* zone, the number of pages is calculated as:
- * present_pages - high_pages
+ * managed_pages - high_pages
*/
static unsigned long nr_free_zone_pages(int offset)
{
@@ -2906,9 +2905,13 @@ EXPORT_SYMBOL(si_meminfo);
#ifdef CONFIG_NUMA
void si_meminfo_node(struct sysinfo *val, int nid)
{
+ int zone_type; /* needs to be signed */
+ unsigned long managed_pages = 0;
pg_data_t *pgdat = NODE_DATA(nid);
- val->totalram = pgdat->node_present_pages;
+ for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++)
+ managed_pages += pgdat->node_zones[zone_type].managed_pages;
+ val->totalram = managed_pages;
val->freeram = node_page_state(nid, NR_FREE_PAGES);
#ifdef CONFIG_HIGHMEM
val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].managed_pages;
@@ -3250,18 +3253,25 @@ int numa_zonelist_order_handler(ctl_table *table, int write,
static DEFINE_MUTEX(zl_order_mutex);
mutex_lock(&zl_order_mutex);
- if (write)
- strcpy(saved_string, (char*)table->data);
+ if (write) {
+ if (strlen((char *)table->data) >= NUMA_ZONELIST_ORDER_LEN) {
+ ret = -EINVAL;
+ goto out;
+ }
+ strcpy(saved_string, (char *)table->data);
+ }
ret = proc_dostring(table, write, buffer, length, ppos);
if (ret)
goto out;
if (write) {
int oldval = user_zonelist_order;
- if (__parse_numa_zonelist_order((char*)table->data)) {
+
+ ret = __parse_numa_zonelist_order((char *)table->data);
+ if (ret) {
/*
* bogus value. restore saved string
*/
- strncpy((char*)table->data, saved_string,
+ strncpy((char *)table->data, saved_string,
NUMA_ZONELIST_ORDER_LEN);
user_zonelist_order = oldval;
} else if (oldval != user_zonelist_order) {
@@ -3425,8 +3435,8 @@ static int default_zonelist_order(void)
z = &NODE_DATA(nid)->node_zones[zone_type];
if (populated_zone(z)) {
if (zone_type < ZONE_NORMAL)
- low_kmem_size += z->present_pages;
- total_size += z->present_pages;
+ low_kmem_size += z->managed_pages;
+ total_size += z->managed_pages;
} else if (zone_type == ZONE_NORMAL) {
/*
* If any node has only lowmem, then node order
@@ -3705,12 +3715,12 @@ void __ref build_all_zonelists(pg_data_t *pgdat, struct zone *zone)
mminit_verify_zonelist();
cpuset_init_current_mems_allowed();
} else {
- /* we have to stop all cpus to guarantee there is no user
- of zonelist */
#ifdef CONFIG_MEMORY_HOTPLUG
if (zone)
setup_zone_pageset(zone);
#endif
+ /* we have to stop all cpus to guarantee there is no user
+ of zonelist */
stop_machine(__build_all_zonelists, pgdat, NULL);
/* cpuset refresh routine should be here */
}
@@ -4032,7 +4042,40 @@ static int __meminit zone_batchsize(struct zone *zone)
#endif
}
-static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
+/*
+ * pcp->high and pcp->batch values are related and dependent on one another:
+ * ->batch must never be higher then ->high.
+ * The following function updates them in a safe manner without read side
+ * locking.
+ *
+ * Any new users of pcp->batch and pcp->high should ensure they can cope with
+ * those fields changing asynchronously (acording the the above rule).
+ *
+ * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
+ * outside of boot time (or some other assurance that no concurrent updaters
+ * exist).
+ */
+static void pageset_update(struct per_cpu_pages *pcp, unsigned long high,
+ unsigned long batch)
+{
+ /* start with a fail safe value for batch */
+ pcp->batch = 1;
+ smp_wmb();
+
+ /* Update high, then batch, in order */
+ pcp->high = high;
+ smp_wmb();
+
+ pcp->batch = batch;
+}
+
+/* a companion to pageset_set_high() */
+static void pageset_set_batch(struct per_cpu_pageset *p, unsigned long batch)
+{
+ pageset_update(&p->pcp, 6 * batch, max(1UL, 1 * batch));
+}
+
+static void pageset_init(struct per_cpu_pageset *p)
{
struct per_cpu_pages *pcp;
int migratetype;
@@ -4041,45 +4084,55 @@ static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
pcp = &p->pcp;
pcp->count = 0;
- pcp->high = 6 * batch;
- pcp->batch = max(1UL, 1 * batch);
for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++)
INIT_LIST_HEAD(&pcp->lists[migratetype]);
}
+static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
+{
+ pageset_init(p);
+ pageset_set_batch(p, batch);
+}
+
/*
- * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist
+ * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
* to the value high for the pageset p.
*/
-
-static void setup_pagelist_highmark(struct per_cpu_pageset *p,
+static void pageset_set_high(struct per_cpu_pageset *p,
unsigned long high)
{
- struct per_cpu_pages *pcp;
+ unsigned long batch = max(1UL, high / 4);
+ if ((high / 4) > (PAGE_SHIFT * 8))
+ batch = PAGE_SHIFT * 8;
- pcp = &p->pcp;
- pcp->high = high;
- pcp->batch = max(1UL, high/4);
- if ((high/4) > (PAGE_SHIFT * 8))
- pcp->batch = PAGE_SHIFT * 8;
+ pageset_update(&p->pcp, high, batch);
}
-static void __meminit setup_zone_pageset(struct zone *zone)
+static void __meminit pageset_set_high_and_batch(struct zone *zone,
+ struct per_cpu_pageset *pcp)
{
- int cpu;
-
- zone->pageset = alloc_percpu(struct per_cpu_pageset);
+ if (percpu_pagelist_fraction)
+ pageset_set_high(pcp,
+ (zone->managed_pages /
+ percpu_pagelist_fraction));
+ else
+ pageset_set_batch(pcp, zone_batchsize(zone));
+}
- for_each_possible_cpu(cpu) {
- struct per_cpu_pageset *pcp = per_cpu_ptr(zone->pageset, cpu);
+static void __meminit zone_pageset_init(struct zone *zone, int cpu)
+{
+ struct per_cpu_pageset *pcp = per_cpu_ptr(zone->pageset, cpu);
- setup_pageset(pcp, zone_batchsize(zone));
+ pageset_init(pcp);
+ pageset_set_high_and_batch(zone, pcp);
+}
- if (percpu_pagelist_fraction)
- setup_pagelist_highmark(pcp,
- (zone->managed_pages /
- percpu_pagelist_fraction));
- }
+static void __meminit setup_zone_pageset(struct zone *zone)
+{
+ int cpu;
+ zone->pageset = alloc_percpu(struct per_cpu_pageset);
+ for_each_possible_cpu(cpu)
+ zone_pageset_init(zone, cpu);
}
/*
@@ -5150,35 +5203,101 @@ early_param("movablecore", cmdline_parse_movablecore);
#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
-unsigned long free_reserved_area(unsigned long start, unsigned long end,
- int poison, char *s)
+void adjust_managed_page_count(struct page *page, long count)
+{
+ spin_lock(&managed_page_count_lock);
+ page_zone(page)->managed_pages += count;
+ totalram_pages += count;
+#ifdef CONFIG_HIGHMEM
+ if (PageHighMem(page))
+ totalhigh_pages += count;
+#endif
+ spin_unlock(&managed_page_count_lock);
+}
+EXPORT_SYMBOL(adjust_managed_page_count);
+
+unsigned long free_reserved_area(void *start, void *end, int poison, char *s)
{
- unsigned long pages, pos;
+ void *pos;
+ unsigned long pages = 0;
- pos = start = PAGE_ALIGN(start);
- end &= PAGE_MASK;
- for (pages = 0; pos < end; pos += PAGE_SIZE, pages++) {
- if (poison)
- memset((void *)pos, poison, PAGE_SIZE);
- free_reserved_page(virt_to_page((void *)pos));
+ start = (void *)PAGE_ALIGN((unsigned long)start);
+ end = (void *)((unsigned long)end & PAGE_MASK);
+ for (pos = start; pos < end; pos += PAGE_SIZE, pages++) {
+ if ((unsigned int)poison <= 0xFF)
+ memset(pos, poison, PAGE_SIZE);
+ free_reserved_page(virt_to_page(pos));
}
if (pages && s)
- pr_info("Freeing %s memory: %ldK (%lx - %lx)\n",
+ pr_info("Freeing %s memory: %ldK (%p - %p)\n",
s, pages << (PAGE_SHIFT - 10), start, end);
return pages;
}
+EXPORT_SYMBOL(free_reserved_area);
#ifdef CONFIG_HIGHMEM
void free_highmem_page(struct page *page)
{
__free_reserved_page(page);
totalram_pages++;
+ page_zone(page)->managed_pages++;
totalhigh_pages++;
}
#endif
+
+void __init mem_init_print_info(const char *str)
+{
+ unsigned long physpages, codesize, datasize, rosize, bss_size;
+ unsigned long init_code_size, init_data_size;
+
+ physpages = get_num_physpages();
+ codesize = _etext - _stext;
+ datasize = _edata - _sdata;
+ rosize = __end_rodata - __start_rodata;
+ bss_size = __bss_stop - __bss_start;
+ init_data_size = __init_end - __init_begin;
+ init_code_size = _einittext - _sinittext;
+
+ /*
+ * Detect special cases and adjust section sizes accordingly:
+ * 1) .init.* may be embedded into .data sections
+ * 2) .init.text.* may be out of [__init_begin, __init_end],
+ * please refer to arch/tile/kernel/vmlinux.lds.S.
+ * 3) .rodata.* may be embedded into .text or .data sections.
+ */
+#define adj_init_size(start, end, size, pos, adj) \
+ if (start <= pos && pos < end && size > adj) \
+ size -= adj;
+
+ adj_init_size(__init_begin, __init_end, init_data_size,
+ _sinittext, init_code_size);
+ adj_init_size(_stext, _etext, codesize, _sinittext, init_code_size);
+ adj_init_size(_sdata, _edata, datasize, __init_begin, init_data_size);
+ adj_init_size(_stext, _etext, codesize, __start_rodata, rosize);
+ adj_init_size(_sdata, _edata, datasize, __start_rodata, rosize);
+
+#undef adj_init_size
+
+ printk("Memory: %luK/%luK available "
+ "(%luK kernel code, %luK rwdata, %luK rodata, "
+ "%luK init, %luK bss, %luK reserved"
+#ifdef CONFIG_HIGHMEM
+ ", %luK highmem"
+#endif
+ "%s%s)\n",
+ nr_free_pages() << (PAGE_SHIFT-10), physpages << (PAGE_SHIFT-10),
+ codesize >> 10, datasize >> 10, rosize >> 10,
+ (init_data_size + init_code_size) >> 10, bss_size >> 10,
+ (physpages - totalram_pages) << (PAGE_SHIFT-10),
+#ifdef CONFIG_HIGHMEM
+ totalhigh_pages << (PAGE_SHIFT-10),
+#endif
+ str ? ", " : "", str ? str : "");
+}
+
/**
* set_dma_reserve - set the specified number of pages reserved in the first zone
* @new_dma_reserve: The number of pages to mark reserved
@@ -5540,7 +5659,6 @@ int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write,
* cpu. It is the fraction of total pages in each zone that a hot per cpu pagelist
* can have before it gets flushed back to buddy allocator.
*/
-
int percpu_pagelist_fraction_sysctl_handler(ctl_table *table, int write,
void __user *buffer, size_t *length, loff_t *ppos)
{
@@ -5551,14 +5669,16 @@ int percpu_pagelist_fraction_sysctl_handler(ctl_table *table, int write,
ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
if (!write || (ret < 0))
return ret;
+
+ mutex_lock(&pcp_batch_high_lock);
for_each_populated_zone(zone) {
- for_each_possible_cpu(cpu) {
- unsigned long high;
- high = zone->managed_pages / percpu_pagelist_fraction;
- setup_pagelist_highmark(
- per_cpu_ptr(zone->pageset, cpu), high);
- }
+ unsigned long high;
+ high = zone->managed_pages / percpu_pagelist_fraction;
+ for_each_possible_cpu(cpu)
+ pageset_set_high(per_cpu_ptr(zone->pageset, cpu),
+ high);
}
+ mutex_unlock(&pcp_batch_high_lock);
return 0;
}
@@ -6047,32 +6167,18 @@ void free_contig_range(unsigned long pfn, unsigned nr_pages)
#endif
#ifdef CONFIG_MEMORY_HOTPLUG
-static int __meminit __zone_pcp_update(void *data)
-{
- struct zone *zone = data;
- int cpu;
- unsigned long batch = zone_batchsize(zone), flags;
-
- for_each_possible_cpu(cpu) {
- struct per_cpu_pageset *pset;
- struct per_cpu_pages *pcp;
-
- pset = per_cpu_ptr(zone->pageset, cpu);
- pcp = &pset->pcp;
-
- local_irq_save(flags);
- if (pcp->count > 0)
- free_pcppages_bulk(zone, pcp->count, pcp);
- drain_zonestat(zone, pset);
- setup_pageset(pset, batch);
- local_irq_restore(flags);
- }
- return 0;
-}
-
+/*
+ * The zone indicated has a new number of managed_pages; batch sizes and percpu
+ * page high values need to be recalulated.
+ */
void __meminit zone_pcp_update(struct zone *zone)
{
- stop_machine(__zone_pcp_update, zone, NULL);
+ unsigned cpu;
+ mutex_lock(&pcp_batch_high_lock);
+ for_each_possible_cpu(cpu)
+ pageset_set_high_and_batch(zone,
+ per_cpu_ptr(zone->pageset, cpu));
+ mutex_unlock(&pcp_batch_high_lock);
}
#endif
@@ -6142,6 +6248,10 @@ __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
list_del(&page->lru);
rmv_page_order(page);
zone->free_area[order].nr_free--;
+#ifdef CONFIG_HIGHMEM
+ if (PageHighMem(page))
+ totalhigh_pages -= 1 << order;
+#endif
for (i = 0; i < (1 << order); i++)
SetPageReserved((page+i));
pfn += (1 << order);
diff --git a/mm/page_io.c b/mm/page_io.c
index a8a3ef45fed7..ba05b64e5d8d 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -21,6 +21,7 @@
#include <linux/writeback.h>
#include <linux/frontswap.h>
#include <linux/aio.h>
+#include <linux/blkdev.h>
#include <asm/pgtable.h>
static struct bio *get_swap_bio(gfp_t gfp_flags,
@@ -80,9 +81,54 @@ void end_swap_bio_read(struct bio *bio, int err)
imajor(bio->bi_bdev->bd_inode),
iminor(bio->bi_bdev->bd_inode),
(unsigned long long)bio->bi_sector);
- } else {
- SetPageUptodate(page);
+ goto out;
}
+
+ SetPageUptodate(page);
+
+ /*
+ * There is no guarantee that the page is in swap cache - the software
+ * suspend code (at least) uses end_swap_bio_read() against a non-
+ * swapcache page. So we must check PG_swapcache before proceeding with
+ * this optimization.
+ */
+ if (likely(PageSwapCache(page))) {
+ struct swap_info_struct *sis;
+
+ sis = page_swap_info(page);
+ if (sis->flags & SWP_BLKDEV) {
+ /*
+ * The swap subsystem performs lazy swap slot freeing,
+ * expecting that the page will be swapped out again.
+ * So we can avoid an unnecessary write if the page
+ * isn't redirtied.
+ * This is good for real swap storage because we can
+ * reduce unnecessary I/O and enhance wear-leveling
+ * if an SSD is used as the as swap device.
+ * But if in-memory swap device (eg zram) is used,
+ * this causes a duplicated copy between uncompressed
+ * data in VM-owned memory and compressed data in
+ * zram-owned memory. So let's free zram-owned memory
+ * and make the VM-owned decompressed page *dirty*,
+ * so the page should be swapped out somewhere again if
+ * we again wish to reclaim it.
+ */
+ struct gendisk *disk = sis->bdev->bd_disk;
+ if (disk->fops->swap_slot_free_notify) {
+ swp_entry_t entry;
+ unsigned long offset;
+
+ entry.val = page_private(page);
+ offset = swp_offset(entry);
+
+ SetPageDirty(page);
+ disk->fops->swap_slot_free_notify(sis->bdev,
+ offset);
+ }
+ }
+ }
+
+out:
unlock_page(page);
bio_put(bio);
}
diff --git a/mm/rmap.c b/mm/rmap.c
index 6280da86b5d6..e22ceeb6e5ec 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1093,9 +1093,10 @@ void page_add_new_anon_rmap(struct page *page,
else
__inc_zone_page_state(page, NR_ANON_TRANSPARENT_HUGEPAGES);
__page_set_anon_rmap(page, vma, address, 1);
- if (!mlocked_vma_newpage(vma, page))
- lru_cache_add_lru(page, LRU_ACTIVE_ANON);
- else
+ if (!mlocked_vma_newpage(vma, page)) {
+ SetPageActive(page);
+ lru_cache_add(page);
+ } else
add_page_to_unevictable_list(page);
}
diff --git a/mm/sparse.c b/mm/sparse.c
index 1c91f0d3f6ab..3194ec414728 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -481,6 +481,9 @@ void __init sparse_init(void)
struct page **map_map;
#endif
+ /* see include/linux/mmzone.h 'struct mem_section' definition */
+ BUILD_BUG_ON(!is_power_of_2(sizeof(struct mem_section)));
+
/* Setup pageblock_order for HUGETLB_PAGE_SIZE_VARIABLE */
set_pageblock_order();
diff --git a/mm/swap.c b/mm/swap.c
index dfd7d71d6841..4a1d0d2c52fa 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -34,10 +34,13 @@
#include "internal.h"
+#define CREATE_TRACE_POINTS
+#include <trace/events/pagemap.h>
+
/* How many pages do we try to swap or page in/out together? */
int page_cluster;
-static DEFINE_PER_CPU(struct pagevec[NR_LRU_LISTS], lru_add_pvecs);
+static DEFINE_PER_CPU(struct pagevec, lru_add_pvec);
static DEFINE_PER_CPU(struct pagevec, lru_rotate_pvecs);
static DEFINE_PER_CPU(struct pagevec, lru_deactivate_pvecs);
@@ -384,6 +387,7 @@ static void __activate_page(struct page *page, struct lruvec *lruvec,
SetPageActive(page);
lru += LRU_ACTIVE;
add_page_to_lru_list(page, lruvec, lru);
+ trace_mm_lru_activate(page, page_to_pfn(page));
__count_vm_event(PGACTIVATE);
update_page_reclaim_stat(lruvec, file, 1);
@@ -428,6 +432,33 @@ void activate_page(struct page *page)
}
#endif
+static void __lru_cache_activate_page(struct page *page)
+{
+ struct pagevec *pvec = &get_cpu_var(lru_add_pvec);
+ int i;
+
+ /*
+ * Search backwards on the optimistic assumption that the page being
+ * activated has just been added to this pagevec. Note that only
+ * the local pagevec is examined as a !PageLRU page could be in the
+ * process of being released, reclaimed, migrated or on a remote
+ * pagevec that is currently being drained. Furthermore, marking
+ * a remote pagevec's page PageActive potentially hits a race where
+ * a page is marked PageActive just after it is added to the inactive
+ * list causing accounting errors and BUG_ON checks to trigger.
+ */
+ for (i = pagevec_count(pvec) - 1; i >= 0; i--) {
+ struct page *pagevec_page = pvec->pages[i];
+
+ if (pagevec_page == page) {
+ SetPageActive(page);
+ break;
+ }
+ }
+
+ put_cpu_var(lru_add_pvec);
+}
+
/*
* Mark a page as having seen activity.
*
@@ -438,8 +469,18 @@ void activate_page(struct page *page)
void mark_page_accessed(struct page *page)
{
if (!PageActive(page) && !PageUnevictable(page) &&
- PageReferenced(page) && PageLRU(page)) {
- activate_page(page);
+ PageReferenced(page)) {
+
+ /*
+ * If the page is on the LRU, queue it for activation via
+ * activate_page_pvecs. Otherwise, assume the page is on a
+ * pagevec, mark it active and it'll be moved to the active
+ * LRU on the next drain.
+ */
+ if (PageLRU(page))
+ activate_page(page);
+ else
+ __lru_cache_activate_page(page);
ClearPageReferenced(page);
} else if (!PageReferenced(page)) {
SetPageReferenced(page);
@@ -448,42 +489,37 @@ void mark_page_accessed(struct page *page)
EXPORT_SYMBOL(mark_page_accessed);
/*
- * Order of operations is important: flush the pagevec when it's already
- * full, not when adding the last page, to make sure that last page is
- * not added to the LRU directly when passed to this function. Because
- * mark_page_accessed() (called after this when writing) only activates
- * pages that are on the LRU, linear writes in subpage chunks would see
- * every PAGEVEC_SIZE page activated, which is unexpected.
+ * Queue the page for addition to the LRU via pagevec. The decision on whether
+ * to add the page to the [in]active [file|anon] list is deferred until the
+ * pagevec is drained. This gives a chance for the caller of __lru_cache_add()
+ * have the page added to the active list using mark_page_accessed().
*/
-void __lru_cache_add(struct page *page, enum lru_list lru)
+void __lru_cache_add(struct page *page)
{
- struct pagevec *pvec = &get_cpu_var(lru_add_pvecs)[lru];
+ struct pagevec *pvec = &get_cpu_var(lru_add_pvec);
page_cache_get(page);
if (!pagevec_space(pvec))
- __pagevec_lru_add(pvec, lru);
+ __pagevec_lru_add(pvec);
pagevec_add(pvec, page);
- put_cpu_var(lru_add_pvecs);
+ put_cpu_var(lru_add_pvec);
}
EXPORT_SYMBOL(__lru_cache_add);
/**
- * lru_cache_add_lru - add a page to a page list
+ * lru_cache_add - add a page to a page list
* @page: the page to be added to the LRU.
- * @lru: the LRU list to which the page is added.
*/
-void lru_cache_add_lru(struct page *page, enum lru_list lru)
+void lru_cache_add(struct page *page)
{
if (PageActive(page)) {
VM_BUG_ON(PageUnevictable(page));
- ClearPageActive(page);
} else if (PageUnevictable(page)) {
VM_BUG_ON(PageActive(page));
- ClearPageUnevictable(page);
}
- VM_BUG_ON(PageLRU(page) || PageActive(page) || PageUnevictable(page));
- __lru_cache_add(page, lru);
+ VM_BUG_ON(PageLRU(page));
+ __lru_cache_add(page);
}
/**
@@ -583,15 +619,10 @@ static void lru_deactivate_fn(struct page *page, struct lruvec *lruvec,
*/
void lru_add_drain_cpu(int cpu)
{
- struct pagevec *pvecs = per_cpu(lru_add_pvecs, cpu);
- struct pagevec *pvec;
- int lru;
+ struct pagevec *pvec = &per_cpu(lru_add_pvec, cpu);
- for_each_lru(lru) {
- pvec = &pvecs[lru - LRU_BASE];
- if (pagevec_count(pvec))
- __pagevec_lru_add(pvec, lru);
- }
+ if (pagevec_count(pvec))
+ __pagevec_lru_add(pvec);
pvec = &per_cpu(lru_rotate_pvecs, cpu);
if (pagevec_count(pvec)) {
@@ -708,6 +739,9 @@ void release_pages(struct page **pages, int nr, int cold)
del_page_from_lru_list(page, lruvec, page_off_lru(page));
}
+ /* Clear Active bit in case of parallel mark_page_accessed */
+ ClearPageActive(page);
+
list_add(&page->lru, &pages_to_free);
}
if (zone)
@@ -795,30 +829,26 @@ void lru_add_page_tail(struct page *page, struct page *page_tail,
static void __pagevec_lru_add_fn(struct page *page, struct lruvec *lruvec,
void *arg)
{
- enum lru_list lru = (enum lru_list)arg;
- int file = is_file_lru(lru);
- int active = is_active_lru(lru);
+ int file = page_is_file_cache(page);
+ int active = PageActive(page);
+ enum lru_list lru = page_lru(page);
- VM_BUG_ON(PageActive(page));
VM_BUG_ON(PageUnevictable(page));
VM_BUG_ON(PageLRU(page));
SetPageLRU(page);
- if (active)
- SetPageActive(page);
add_page_to_lru_list(page, lruvec, lru);
update_page_reclaim_stat(lruvec, file, active);
+ trace_mm_lru_insertion(page, page_to_pfn(page), lru, trace_pagemap_flags(page));
}
/*
* Add the passed pages to the LRU, then drop the caller's refcount
* on them. Reinitialises the caller's pagevec.
*/
-void __pagevec_lru_add(struct pagevec *pvec, enum lru_list lru)
+void __pagevec_lru_add(struct pagevec *pvec)
{
- VM_BUG_ON(is_unevictable_lru(lru));
-
- pagevec_lru_move_fn(pvec, __pagevec_lru_add_fn, (void *)lru);
+ pagevec_lru_move_fn(pvec, __pagevec_lru_add_fn, NULL);
}
EXPORT_SYMBOL(__pagevec_lru_add);
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 746af55b8455..36af6eeaa67e 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -212,7 +212,7 @@ static unsigned long scan_swap_map(struct swap_info_struct *si,
si->cluster_nr = SWAPFILE_CLUSTER - 1;
goto checks;
}
- if (si->flags & SWP_DISCARDABLE) {
+ if (si->flags & SWP_PAGE_DISCARD) {
/*
* Start range check on racing allocations, in case
* they overlap the cluster we eventually decide on
@@ -322,7 +322,7 @@ checks:
if (si->lowest_alloc) {
/*
- * Only set when SWP_DISCARDABLE, and there's a scan
+ * Only set when SWP_PAGE_DISCARD, and there's a scan
* for a free cluster in progress or just completed.
*/
if (found_free_cluster) {
@@ -2016,6 +2016,20 @@ static int setup_swap_map_and_extents(struct swap_info_struct *p,
return nr_extents;
}
+/*
+ * Helper to sys_swapon determining if a given swap
+ * backing device queue supports DISCARD operations.
+ */
+static bool swap_discardable(struct swap_info_struct *si)
+{
+ struct request_queue *q = bdev_get_queue(si->bdev);
+
+ if (!q || !blk_queue_discard(q))
+ return false;
+
+ return true;
+}
+
SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
{
struct swap_info_struct *p;
@@ -2123,8 +2137,37 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
p->flags |= SWP_SOLIDSTATE;
p->cluster_next = 1 + (prandom_u32() % p->highest_bit);
}
- if ((swap_flags & SWAP_FLAG_DISCARD) && discard_swap(p) == 0)
- p->flags |= SWP_DISCARDABLE;
+
+ if ((swap_flags & SWAP_FLAG_DISCARD) && swap_discardable(p)) {
+ /*
+ * When discard is enabled for swap with no particular
+ * policy flagged, we set all swap discard flags here in
+ * order to sustain backward compatibility with older
+ * swapon(8) releases.
+ */
+ p->flags |= (SWP_DISCARDABLE | SWP_AREA_DISCARD |
+ SWP_PAGE_DISCARD);
+
+ /*
+ * By flagging sys_swapon, a sysadmin can tell us to
+ * either do single-time area discards only, or to just
+ * perform discards for released swap page-clusters.
+ * Now it's time to adjust the p->flags accordingly.
+ */
+ if (swap_flags & SWAP_FLAG_DISCARD_ONCE)
+ p->flags &= ~SWP_PAGE_DISCARD;
+ else if (swap_flags & SWAP_FLAG_DISCARD_PAGES)
+ p->flags &= ~SWP_AREA_DISCARD;
+
+ /* issue a swapon-time discard if it's still required */
+ if (p->flags & SWP_AREA_DISCARD) {
+ int err = discard_swap(p);
+ if (unlikely(err))
+ printk(KERN_ERR
+ "swapon: discard_swap(%p): %d\n",
+ p, err);
+ }
+ }
}
mutex_lock(&swapon_mutex);
@@ -2135,11 +2178,13 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
enable_swap_info(p, prio, swap_map, frontswap_map);
printk(KERN_INFO "Adding %uk swap on %s. "
- "Priority:%d extents:%d across:%lluk %s%s%s\n",
+ "Priority:%d extents:%d across:%lluk %s%s%s%s%s\n",
p->pages<<(PAGE_SHIFT-10), name->name, p->prio,
nr_extents, (unsigned long long)span<<(PAGE_SHIFT-10),
(p->flags & SWP_SOLIDSTATE) ? "SS" : "",
(p->flags & SWP_DISCARDABLE) ? "D" : "",
+ (p->flags & SWP_AREA_DISCARD) ? "s" : "",
+ (p->flags & SWP_PAGE_DISCARD) ? "c" : "",
(frontswap_map) ? "FS" : "");
mutex_unlock(&swapon_mutex);
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index d365724feb05..91a10472a39a 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -292,7 +292,7 @@ static struct vmap_area *__find_vmap_area(unsigned long addr)
va = rb_entry(n, struct vmap_area, rb_node);
if (addr < va->va_start)
n = n->rb_left;
- else if (addr > va->va_start)
+ else if (addr >= va->va_end)
n = n->rb_right;
else
return va;
@@ -1322,13 +1322,6 @@ static void clear_vm_unlist(struct vm_struct *vm)
vm->flags &= ~VM_UNLIST;
}
-static void insert_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va,
- unsigned long flags, const void *caller)
-{
- setup_vmalloc_vm(vm, va, flags, caller);
- clear_vm_unlist(vm);
-}
-
static struct vm_struct *__get_vm_area_node(unsigned long size,
unsigned long align, unsigned long flags, unsigned long start,
unsigned long end, int node, gfp_t gfp_mask, const void *caller)
@@ -1337,16 +1330,8 @@ static struct vm_struct *__get_vm_area_node(unsigned long size,
struct vm_struct *area;
BUG_ON(in_interrupt());
- if (flags & VM_IOREMAP) {
- int bit = fls(size);
-
- if (bit > IOREMAP_MAX_ORDER)
- bit = IOREMAP_MAX_ORDER;
- else if (bit < PAGE_SHIFT)
- bit = PAGE_SHIFT;
-
- align = 1ul << bit;
- }
+ if (flags & VM_IOREMAP)
+ align = 1ul << clamp(fls(size), PAGE_SHIFT, IOREMAP_MAX_ORDER);
size = PAGE_ALIGN(size);
if (unlikely(!size))
@@ -1367,16 +1352,7 @@ static struct vm_struct *__get_vm_area_node(unsigned long size,
return NULL;
}
- /*
- * When this function is called from __vmalloc_node_range,
- * we add VM_UNLIST flag to avoid accessing uninitialized
- * members of vm_struct such as pages and nr_pages fields.
- * They will be set later.
- */
- if (flags & VM_UNLIST)
- setup_vmalloc_vm(area, va, flags, caller);
- else
- insert_vmalloc_vm(area, va, flags, caller);
+ setup_vmalloc_vm(area, va, flags, caller);
return area;
}
@@ -1476,10 +1452,9 @@ static void __vunmap(const void *addr, int deallocate_pages)
if (!addr)
return;
- if ((PAGE_SIZE-1) & (unsigned long)addr) {
- WARN(1, KERN_ERR "Trying to vfree() bad address (%p)\n", addr);
+ if (WARN(!PAGE_ALIGNED(addr), "Trying to vfree() bad address (%p)\n",
+ addr));
return;
- }
area = remove_vm_area(addr);
if (unlikely(!area)) {
@@ -2148,42 +2123,43 @@ finished:
}
/**
- * remap_vmalloc_range - map vmalloc pages to userspace
- * @vma: vma to cover (map full range of vma)
- * @addr: vmalloc memory
- * @pgoff: number of pages into addr before first page to map
+ * remap_vmalloc_range_partial - map vmalloc pages to userspace
+ * @vma: vma to cover
+ * @uaddr: target user address to start at
+ * @kaddr: virtual address of vmalloc kernel memory
+ * @size: size of map area
*
* Returns: 0 for success, -Exxx on failure
*
- * This function checks that addr is a valid vmalloc'ed area, and
- * that it is big enough to cover the vma. Will return failure if
- * that criteria isn't met.
+ * This function checks that @kaddr is a valid vmalloc'ed area,
+ * and that it is big enough to cover the range starting at
+ * @uaddr in @vma. Will return failure if that criteria isn't
+ * met.
*
* Similar to remap_pfn_range() (see mm/memory.c)
*/
-int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
- unsigned long pgoff)
+int remap_vmalloc_range_partial(struct vm_area_struct *vma, unsigned long uaddr,
+ void *kaddr, unsigned long size)
{
struct vm_struct *area;
- unsigned long uaddr = vma->vm_start;
- unsigned long usize = vma->vm_end - vma->vm_start;
- if ((PAGE_SIZE-1) & (unsigned long)addr)
+ size = PAGE_ALIGN(size);
+
+ if (!PAGE_ALIGNED(uaddr) || !PAGE_ALIGNED(kaddr))
return -EINVAL;
- area = find_vm_area(addr);
+ area = find_vm_area(kaddr);
if (!area)
return -EINVAL;
if (!(area->flags & VM_USERMAP))
return -EINVAL;
- if (usize + (pgoff << PAGE_SHIFT) > area->size - PAGE_SIZE)
+ if (kaddr + size > area->addr + area->size)
return -EINVAL;
- addr += pgoff << PAGE_SHIFT;
do {
- struct page *page = vmalloc_to_page(addr);
+ struct page *page = vmalloc_to_page(kaddr);
int ret;
ret = vm_insert_page(vma, uaddr, page);
@@ -2191,14 +2167,37 @@ int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
return ret;
uaddr += PAGE_SIZE;
- addr += PAGE_SIZE;
- usize -= PAGE_SIZE;
- } while (usize > 0);
+ kaddr += PAGE_SIZE;
+ size -= PAGE_SIZE;
+ } while (size > 0);
vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
return 0;
}
+EXPORT_SYMBOL(remap_vmalloc_range_partial);
+
+/**
+ * remap_vmalloc_range - map vmalloc pages to userspace
+ * @vma: vma to cover (map full range of vma)
+ * @addr: vmalloc memory
+ * @pgoff: number of pages into addr before first page to map
+ *
+ * Returns: 0 for success, -Exxx on failure
+ *
+ * This function checks that addr is a valid vmalloc'ed area, and
+ * that it is big enough to cover the vma. Will return failure if
+ * that criteria isn't met.
+ *
+ * Similar to remap_pfn_range() (see mm/memory.c)
+ */
+int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
+ unsigned long pgoff)
+{
+ return remap_vmalloc_range_partial(vma, vma->vm_start,
+ addr + (pgoff << PAGE_SHIFT),
+ vma->vm_end - vma->vm_start);
+}
EXPORT_SYMBOL(remap_vmalloc_range);
/*
@@ -2512,8 +2511,8 @@ found:
/* insert all vm's */
for (area = 0; area < nr_vms; area++)
- insert_vmalloc_vm(vms[area], vas[area], VM_ALLOC,
- pcpu_get_vm_areas);
+ setup_vmalloc_vm(vms[area], vas[area], VM_ALLOC,
+ pcpu_get_vm_areas);
kfree(vas);
return vms;
diff --git a/mm/vmscan.c b/mm/vmscan.c
index fa6a85378ee4..99b3ac7771ad 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -546,7 +546,6 @@ int remove_mapping(struct address_space *mapping, struct page *page)
void putback_lru_page(struct page *page)
{
int lru;
- int active = !!TestClearPageActive(page);
int was_unevictable = PageUnevictable(page);
VM_BUG_ON(PageLRU(page));
@@ -561,8 +560,8 @@ redo:
* unevictable page on [in]active list.
* We know how to handle that.
*/
- lru = active + page_lru_base_type(page);
- lru_cache_add_lru(page, lru);
+ lru = page_lru_base_type(page);
+ lru_cache_add(page);
} else {
/*
* Put unevictable pages directly on zone's unevictable
@@ -669,6 +668,35 @@ static enum page_references page_check_references(struct page *page,
return PAGEREF_RECLAIM;
}
+/* Check if a page is dirty or under writeback */
+static void page_check_dirty_writeback(struct page *page,
+ bool *dirty, bool *writeback)
+{
+ struct address_space *mapping;
+
+ /*
+ * Anonymous pages are not handled by flushers and must be written
+ * from reclaim context. Do not stall reclaim based on them
+ */
+ if (!page_is_file_cache(page)) {
+ *dirty = false;
+ *writeback = false;
+ return;
+ }
+
+ /* By default assume that the page flags are accurate */
+ *dirty = PageDirty(page);
+ *writeback = PageWriteback(page);
+
+ /* Verify dirty/writeback state if the filesystem supports it */
+ if (!page_has_private(page))
+ return;
+
+ mapping = page_mapping(page);
+ if (mapping && mapping->a_ops->is_dirty_writeback)
+ mapping->a_ops->is_dirty_writeback(page, dirty, writeback);
+}
+
/*
* shrink_page_list() returns the number of reclaimed pages
*/
@@ -677,16 +705,21 @@ static unsigned long shrink_page_list(struct list_head *page_list,
struct scan_control *sc,
enum ttu_flags ttu_flags,
unsigned long *ret_nr_dirty,
+ unsigned long *ret_nr_unqueued_dirty,
+ unsigned long *ret_nr_congested,
unsigned long *ret_nr_writeback,
+ unsigned long *ret_nr_immediate,
bool force_reclaim)
{
LIST_HEAD(ret_pages);
LIST_HEAD(free_pages);
int pgactivate = 0;
+ unsigned long nr_unqueued_dirty = 0;
unsigned long nr_dirty = 0;
unsigned long nr_congested = 0;
unsigned long nr_reclaimed = 0;
unsigned long nr_writeback = 0;
+ unsigned long nr_immediate = 0;
cond_resched();
@@ -696,6 +729,7 @@ static unsigned long shrink_page_list(struct list_head *page_list,
struct page *page;
int may_enter_fs;
enum page_references references = PAGEREF_RECLAIM_CLEAN;
+ bool dirty, writeback;
cond_resched();
@@ -723,25 +757,77 @@ static unsigned long shrink_page_list(struct list_head *page_list,
may_enter_fs = (sc->gfp_mask & __GFP_FS) ||
(PageSwapCache(page) && (sc->gfp_mask & __GFP_IO));
+ /*
+ * The number of dirty pages determines if a zone is marked
+ * reclaim_congested which affects wait_iff_congested. kswapd
+ * will stall and start writing pages if the tail of the LRU
+ * is all dirty unqueued pages.
+ */
+ page_check_dirty_writeback(page, &dirty, &writeback);
+ if (dirty || writeback)
+ nr_dirty++;
+
+ if (dirty && !writeback)
+ nr_unqueued_dirty++;
+
+ /*
+ * Treat this page as congested if the underlying BDI is or if
+ * pages are cycling through the LRU so quickly that the
+ * pages marked for immediate reclaim are making it to the
+ * end of the LRU a second time.
+ */
+ mapping = page_mapping(page);
+ if ((mapping && bdi_write_congested(mapping->backing_dev_info)) ||
+ (writeback && PageReclaim(page)))
+ nr_congested++;
+
+ /*
+ * If a page at the tail of the LRU is under writeback, there
+ * are three cases to consider.
+ *
+ * 1) If reclaim is encountering an excessive number of pages
+ * under writeback and this page is both under writeback and
+ * PageReclaim then it indicates that pages are being queued
+ * for IO but are being recycled through the LRU before the
+ * IO can complete. Waiting on the page itself risks an
+ * indefinite stall if it is impossible to writeback the
+ * page due to IO error or disconnected storage so instead
+ * note that the LRU is being scanned too quickly and the
+ * caller can stall after page list has been processed.
+ *
+ * 2) Global reclaim encounters a page, memcg encounters a
+ * page that is not marked for immediate reclaim or
+ * the caller does not have __GFP_IO. In this case mark
+ * the page for immediate reclaim and continue scanning.
+ *
+ * __GFP_IO is checked because a loop driver thread might
+ * enter reclaim, and deadlock if it waits on a page for
+ * which it is needed to do the write (loop masks off
+ * __GFP_IO|__GFP_FS for this reason); but more thought
+ * would probably show more reasons.
+ *
+ * Don't require __GFP_FS, since we're not going into the
+ * FS, just waiting on its writeback completion. Worryingly,
+ * ext4 gfs2 and xfs allocate pages with
+ * grab_cache_page_write_begin(,,AOP_FLAG_NOFS), so testing
+ * may_enter_fs here is liable to OOM on them.
+ *
+ * 3) memcg encounters a page that is not already marked
+ * PageReclaim. memcg does not have any dirty pages
+ * throttling so we could easily OOM just because too many
+ * pages are in writeback and there is nothing else to
+ * reclaim. Wait for the writeback to complete.
+ */
if (PageWriteback(page)) {
- /*
- * memcg doesn't have any dirty pages throttling so we
- * could easily OOM just because too many pages are in
- * writeback and there is nothing else to reclaim.
- *
- * Check __GFP_IO, certainly because a loop driver
- * thread might enter reclaim, and deadlock if it waits
- * on a page for which it is needed to do the write
- * (loop masks off __GFP_IO|__GFP_FS for this reason);
- * but more thought would probably show more reasons.
- *
- * Don't require __GFP_FS, since we're not going into
- * the FS, just waiting on its writeback completion.
- * Worryingly, ext4 gfs2 and xfs allocate pages with
- * grab_cache_page_write_begin(,,AOP_FLAG_NOFS), so
- * testing may_enter_fs here is liable to OOM on them.
- */
- if (global_reclaim(sc) ||
+ /* Case 1 above */
+ if (current_is_kswapd() &&
+ PageReclaim(page) &&
+ zone_is_reclaim_writeback(zone)) {
+ nr_immediate++;
+ goto keep_locked;
+
+ /* Case 2 above */
+ } else if (global_reclaim(sc) ||
!PageReclaim(page) || !(sc->gfp_mask & __GFP_IO)) {
/*
* This is slightly racy - end_page_writeback()
@@ -756,9 +842,13 @@ static unsigned long shrink_page_list(struct list_head *page_list,
*/
SetPageReclaim(page);
nr_writeback++;
+
goto keep_locked;
+
+ /* Case 3 above */
+ } else {
+ wait_on_page_writeback(page);
}
- wait_on_page_writeback(page);
}
if (!force_reclaim)
@@ -784,9 +874,10 @@ static unsigned long shrink_page_list(struct list_head *page_list,
if (!add_to_swap(page, page_list))
goto activate_locked;
may_enter_fs = 1;
- }
- mapping = page_mapping(page);
+ /* Adding to swap updated mapping */
+ mapping = page_mapping(page);
+ }
/*
* The page is mapped into the page tables of one or more
@@ -806,16 +897,14 @@ static unsigned long shrink_page_list(struct list_head *page_list,
}
if (PageDirty(page)) {
- nr_dirty++;
-
/*
* Only kswapd can writeback filesystem pages to
- * avoid risk of stack overflow but do not writeback
- * unless under significant pressure.
+ * avoid risk of stack overflow but only writeback
+ * if many dirty pages have been encountered.
*/
if (page_is_file_cache(page) &&
(!current_is_kswapd() ||
- sc->priority >= DEF_PRIORITY - 2)) {
+ !zone_is_reclaim_dirty(zone))) {
/*
* Immediately reclaim when written back.
* Similar in principal to deactivate_page()
@@ -838,7 +927,6 @@ static unsigned long shrink_page_list(struct list_head *page_list,
/* Page is dirty, try to write it out here */
switch (pageout(page, mapping, sc)) {
case PAGE_KEEP:
- nr_congested++;
goto keep_locked;
case PAGE_ACTIVATE:
goto activate_locked;
@@ -946,22 +1034,16 @@ keep:
VM_BUG_ON(PageLRU(page) || PageUnevictable(page));
}
- /*
- * Tag a zone as congested if all the dirty pages encountered were
- * backed by a congested BDI. In this case, reclaimers should just
- * back off and wait for congestion to clear because further reclaim
- * will encounter the same problem
- */
- if (nr_dirty && nr_dirty == nr_congested && global_reclaim(sc))
- zone_set_flag(zone, ZONE_CONGESTED);
-
free_hot_cold_page_list(&free_pages, 1);
list_splice(&ret_pages, page_list);
count_vm_events(PGACTIVATE, pgactivate);
mem_cgroup_uncharge_end();
*ret_nr_dirty += nr_dirty;
+ *ret_nr_congested += nr_congested;
+ *ret_nr_unqueued_dirty += nr_unqueued_dirty;
*ret_nr_writeback += nr_writeback;
+ *ret_nr_immediate += nr_immediate;
return nr_reclaimed;
}
@@ -973,7 +1055,7 @@ unsigned long reclaim_clean_pages_from_list(struct zone *zone,
.priority = DEF_PRIORITY,
.may_unmap = 1,
};
- unsigned long ret, dummy1, dummy2;
+ unsigned long ret, dummy1, dummy2, dummy3, dummy4, dummy5;
struct page *page, *next;
LIST_HEAD(clean_pages);
@@ -985,8 +1067,8 @@ unsigned long reclaim_clean_pages_from_list(struct zone *zone,
}
ret = shrink_page_list(&clean_pages, zone, &sc,
- TTU_UNMAP|TTU_IGNORE_ACCESS,
- &dummy1, &dummy2, true);
+ TTU_UNMAP|TTU_IGNORE_ACCESS,
+ &dummy1, &dummy2, &dummy3, &dummy4, &dummy5, true);
list_splice(&clean_pages, page_list);
__mod_zone_page_state(zone, NR_ISOLATED_FILE, -ret);
return ret;
@@ -1281,7 +1363,10 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec,
unsigned long nr_reclaimed = 0;
unsigned long nr_taken;
unsigned long nr_dirty = 0;
+ unsigned long nr_congested = 0;
+ unsigned long nr_unqueued_dirty = 0;
unsigned long nr_writeback = 0;
+ unsigned long nr_immediate = 0;
isolate_mode_t isolate_mode = 0;
int file = is_file_lru(lru);
struct zone *zone = lruvec_zone(lruvec);
@@ -1323,7 +1408,9 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec,
return 0;
nr_reclaimed = shrink_page_list(&page_list, zone, sc, TTU_UNMAP,
- &nr_dirty, &nr_writeback, false);
+ &nr_dirty, &nr_unqueued_dirty, &nr_congested,
+ &nr_writeback, &nr_immediate,
+ false);
spin_lock_irq(&zone->lru_lock);
@@ -1357,7 +1444,7 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec,
* same way balance_dirty_pages() manages.
*
* This scales the number of dirty pages that must be under writeback
- * before throttling depending on priority. It is a simple backoff
+ * before a zone gets flagged ZONE_WRITEBACK. It is a simple backoff
* function that has the most effect in the range DEF_PRIORITY to
* DEF_PRIORITY-2 which is the priority reclaim is considered to be
* in trouble and reclaim is considered to be in trouble.
@@ -1368,9 +1455,53 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec,
* ...
* DEF_PRIORITY-6 For SWAP_CLUSTER_MAX isolated pages, throttle if any
* isolated page is PageWriteback
+ *
+ * Once a zone is flagged ZONE_WRITEBACK, kswapd will count the number
+ * of pages under pages flagged for immediate reclaim and stall if any
+ * are encountered in the nr_immediate check below.
*/
if (nr_writeback && nr_writeback >=
(nr_taken >> (DEF_PRIORITY - sc->priority)))
+ zone_set_flag(zone, ZONE_WRITEBACK);
+
+ /*
+ * memcg will stall in page writeback so only consider forcibly
+ * stalling for global reclaim
+ */
+ if (global_reclaim(sc)) {
+ /*
+ * Tag a zone as congested if all the dirty pages scanned were
+ * backed by a congested BDI and wait_iff_congested will stall.
+ */
+ if (nr_dirty && nr_dirty == nr_congested)
+ zone_set_flag(zone, ZONE_CONGESTED);
+
+ /*
+ * If dirty pages are scanned that are not queued for IO, it
+ * implies that flushers are not keeping up. In this case, flag
+ * the zone ZONE_TAIL_LRU_DIRTY and kswapd will start writing
+ * pages from reclaim context. It will forcibly stall in the
+ * next check.
+ */
+ if (nr_unqueued_dirty == nr_taken)
+ zone_set_flag(zone, ZONE_TAIL_LRU_DIRTY);
+
+ /*
+ * In addition, if kswapd scans pages marked marked for
+ * immediate reclaim and under writeback (nr_immediate), it
+ * implies that pages are cycling through the LRU faster than
+ * they are written so also forcibly stall.
+ */
+ if (nr_unqueued_dirty == nr_taken || nr_immediate)
+ congestion_wait(BLK_RW_ASYNC, HZ/10);
+ }
+
+ /*
+ * Stall direct reclaim for IO completions if underlying BDIs or zone
+ * is congested. Allow kswapd to continue until it starts encountering
+ * unqueued dirty pages or cycling through the LRU too quickly.
+ */
+ if (!sc->hibernation_mode && !current_is_kswapd())
wait_iff_congested(zone, BLK_RW_ASYNC, HZ/10);
trace_mm_vmscan_lru_shrink_inactive(zone->zone_pgdat->node_id,
@@ -1822,17 +1953,25 @@ out:
static void shrink_lruvec(struct lruvec *lruvec, struct scan_control *sc)
{
unsigned long nr[NR_LRU_LISTS];
+ unsigned long targets[NR_LRU_LISTS];
unsigned long nr_to_scan;
enum lru_list lru;
unsigned long nr_reclaimed = 0;
unsigned long nr_to_reclaim = sc->nr_to_reclaim;
struct blk_plug plug;
+ bool scan_adjusted = false;
get_scan_count(lruvec, sc, nr);
+ /* Record the original scan target for proportional adjustments later */
+ memcpy(targets, nr, sizeof(nr));
+
blk_start_plug(&plug);
while (nr[LRU_INACTIVE_ANON] || nr[LRU_ACTIVE_FILE] ||
nr[LRU_INACTIVE_FILE]) {
+ unsigned long nr_anon, nr_file, percentage;
+ unsigned long nr_scanned;
+
for_each_evictable_lru(lru) {
if (nr[lru]) {
nr_to_scan = min(nr[lru], SWAP_CLUSTER_MAX);
@@ -1842,17 +1981,60 @@ static void shrink_lruvec(struct lruvec *lruvec, struct scan_control *sc)
lruvec, sc);
}
}
+
+ if (nr_reclaimed < nr_to_reclaim || scan_adjusted)
+ continue;
+
/*
- * On large memory systems, scan >> priority can become
- * really large. This is fine for the starting priority;
- * we want to put equal scanning pressure on each zone.
- * However, if the VM has a harder time of freeing pages,
- * with multiple processes reclaiming pages, the total
- * freeing target can get unreasonably large.
+ * For global direct reclaim, reclaim only the number of pages
+ * requested. Less care is taken to scan proportionally as it
+ * is more important to minimise direct reclaim stall latency
+ * than it is to properly age the LRU lists.
*/
- if (nr_reclaimed >= nr_to_reclaim &&
- sc->priority < DEF_PRIORITY)
+ if (global_reclaim(sc) && !current_is_kswapd())
break;
+
+ /*
+ * For kswapd and memcg, reclaim at least the number of pages
+ * requested. Ensure that the anon and file LRUs shrink
+ * proportionally what was requested by get_scan_count(). We
+ * stop reclaiming one LRU and reduce the amount scanning
+ * proportional to the original scan target.
+ */
+ nr_file = nr[LRU_INACTIVE_FILE] + nr[LRU_ACTIVE_FILE];
+ nr_anon = nr[LRU_INACTIVE_ANON] + nr[LRU_ACTIVE_ANON];
+
+ if (nr_file > nr_anon) {
+ unsigned long scan_target = targets[LRU_INACTIVE_ANON] +
+ targets[LRU_ACTIVE_ANON] + 1;
+ lru = LRU_BASE;
+ percentage = nr_anon * 100 / scan_target;
+ } else {
+ unsigned long scan_target = targets[LRU_INACTIVE_FILE] +
+ targets[LRU_ACTIVE_FILE] + 1;
+ lru = LRU_FILE;
+ percentage = nr_file * 100 / scan_target;
+ }
+
+ /* Stop scanning the smaller of the LRU */
+ nr[lru] = 0;
+ nr[lru + LRU_ACTIVE] = 0;
+
+ /*
+ * Recalculate the other LRU scan count based on its original
+ * scan target and the percentage scanning already complete
+ */
+ lru = (lru == LRU_FILE) ? LRU_BASE : LRU_FILE;
+ nr_scanned = targets[lru] - nr[lru];
+ nr[lru] = targets[lru] * (100 - percentage) / 100;
+ nr[lru] -= min(nr[lru], nr_scanned);
+
+ lru += LRU_ACTIVE;
+ nr_scanned = targets[lru] - nr[lru];
+ nr[lru] = targets[lru] * (100 - percentage) / 100;
+ nr[lru] -= min(nr[lru], nr_scanned);
+
+ scan_adjusted = true;
}
blk_finish_plug(&plug);
sc->nr_reclaimed += nr_reclaimed;
@@ -2222,17 +2404,6 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
WB_REASON_TRY_TO_FREE_PAGES);
sc->may_writepage = 1;
}
-
- /* Take a nap, wait for some writeback to complete */
- if (!sc->hibernation_mode && sc->nr_scanned &&
- sc->priority < DEF_PRIORITY - 2) {
- struct zone *preferred_zone;
-
- first_zones_zonelist(zonelist, gfp_zone(sc->gfp_mask),
- &cpuset_current_mems_allowed,
- &preferred_zone);
- wait_iff_congested(preferred_zone, BLK_RW_ASYNC, HZ/10);
- }
} while (--sc->priority >= 0);
out:
@@ -2601,6 +2772,91 @@ static bool prepare_kswapd_sleep(pg_data_t *pgdat, int order, long remaining,
}
/*
+ * kswapd shrinks the zone by the number of pages required to reach
+ * the high watermark.
+ *
+ * Returns true if kswapd scanned at least the requested number of pages to
+ * reclaim or if the lack of progress was due to pages under writeback.
+ * This is used to determine if the scanning priority needs to be raised.
+ */
+static bool kswapd_shrink_zone(struct zone *zone,
+ int classzone_idx,
+ struct scan_control *sc,
+ unsigned long lru_pages,
+ unsigned long *nr_attempted)
+{
+ unsigned long nr_slab;
+ int testorder = sc->order;
+ unsigned long balance_gap;
+ struct reclaim_state *reclaim_state = current->reclaim_state;
+ struct shrink_control shrink = {
+ .gfp_mask = sc->gfp_mask,
+ };
+ bool lowmem_pressure;
+
+ /* Reclaim above the high watermark. */
+ sc->nr_to_reclaim = max(SWAP_CLUSTER_MAX, high_wmark_pages(zone));
+
+ /*
+ * Kswapd reclaims only single pages with compaction enabled. Trying
+ * too hard to reclaim until contiguous free pages have become
+ * available can hurt performance by evicting too much useful data
+ * from memory. Do not reclaim more than needed for compaction.
+ */
+ if (IS_ENABLED(CONFIG_COMPACTION) && sc->order &&
+ compaction_suitable(zone, sc->order) !=
+ COMPACT_SKIPPED)
+ testorder = 0;
+
+ /*
+ * We put equal pressure on every zone, unless one zone has way too
+ * many pages free already. The "too many pages" is defined as the
+ * high wmark plus a "gap" where the gap is either the low
+ * watermark or 1% of the zone, whichever is smaller.
+ */
+ balance_gap = min(low_wmark_pages(zone),
+ (zone->managed_pages + KSWAPD_ZONE_BALANCE_GAP_RATIO-1) /
+ KSWAPD_ZONE_BALANCE_GAP_RATIO);
+
+ /*
+ * If there is no low memory pressure or the zone is balanced then no
+ * reclaim is necessary
+ */
+ lowmem_pressure = (buffer_heads_over_limit && is_highmem(zone));
+ if (!lowmem_pressure && zone_balanced(zone, testorder,
+ balance_gap, classzone_idx))
+ return true;
+
+ shrink_zone(zone, sc);
+
+ reclaim_state->reclaimed_slab = 0;
+ nr_slab = shrink_slab(&shrink, sc->nr_scanned, lru_pages);
+ sc->nr_reclaimed += reclaim_state->reclaimed_slab;
+
+ /* Account for the number of pages attempted to reclaim */
+ *nr_attempted += sc->nr_to_reclaim;
+
+ if (nr_slab == 0 && !zone_reclaimable(zone))
+ zone->all_unreclaimable = 1;
+
+ zone_clear_flag(zone, ZONE_WRITEBACK);
+
+ /*
+ * If a zone reaches its high watermark, consider it to be no longer
+ * congested. It's possible there are dirty pages backed by congested
+ * BDIs but as pressure is relieved, speculatively avoid congestion
+ * waits.
+ */
+ if (!zone->all_unreclaimable &&
+ zone_balanced(zone, testorder, 0, classzone_idx)) {
+ zone_clear_flag(zone, ZONE_CONGESTED);
+ zone_clear_flag(zone, ZONE_TAIL_LRU_DIRTY);
+ }
+
+ return sc->nr_scanned >= sc->nr_to_reclaim;
+}
+
+/*
* For kswapd, balance_pgdat() will work across all this node's zones until
* they are all at high_wmark_pages(zone).
*
@@ -2624,35 +2880,28 @@ static bool prepare_kswapd_sleep(pg_data_t *pgdat, int order, long remaining,
static unsigned long balance_pgdat(pg_data_t *pgdat, int order,
int *classzone_idx)
{
- bool pgdat_is_balanced = false;
int i;
int end_zone = 0; /* Inclusive. 0 = ZONE_DMA */
- struct reclaim_state *reclaim_state = current->reclaim_state;
unsigned long nr_soft_reclaimed;
unsigned long nr_soft_scanned;
struct scan_control sc = {
.gfp_mask = GFP_KERNEL,
+ .priority = DEF_PRIORITY,
.may_unmap = 1,
.may_swap = 1,
- /*
- * kswapd doesn't want to be bailed out while reclaim. because
- * we want to put equal scanning pressure on each zone.
- */
- .nr_to_reclaim = ULONG_MAX,
+ .may_writepage = !laptop_mode,
.order = order,
.target_mem_cgroup = NULL,
};
- struct shrink_control shrink = {
- .gfp_mask = sc.gfp_mask,
- };
-loop_again:
- sc.priority = DEF_PRIORITY;
- sc.nr_reclaimed = 0;
- sc.may_writepage = !laptop_mode;
count_vm_event(PAGEOUTRUN);
do {
unsigned long lru_pages = 0;
+ unsigned long nr_attempted = 0;
+ bool raise_priority = true;
+ bool pgdat_needs_compaction = (order > 0);
+
+ sc.nr_reclaimed = 0;
/*
* Scan in the highmem->dma direction for the highest
@@ -2689,23 +2938,46 @@ loop_again:
end_zone = i;
break;
} else {
- /* If balanced, clear the congested flag */
+ /*
+ * If balanced, clear the dirty and congested
+ * flags
+ */
zone_clear_flag(zone, ZONE_CONGESTED);
+ zone_clear_flag(zone, ZONE_TAIL_LRU_DIRTY);
}
}
- if (i < 0) {
- pgdat_is_balanced = true;
+ if (i < 0)
goto out;
- }
for (i = 0; i <= end_zone; i++) {
struct zone *zone = pgdat->node_zones + i;
+ if (!populated_zone(zone))
+ continue;
+
lru_pages += zone_reclaimable_pages(zone);
+
+ /*
+ * If any zone is currently balanced then kswapd will
+ * not call compaction as it is expected that the
+ * necessary pages are already available.
+ */
+ if (pgdat_needs_compaction &&
+ zone_watermark_ok(zone, order,
+ low_wmark_pages(zone),
+ *classzone_idx, 0))
+ pgdat_needs_compaction = false;
}
/*
+ * If we're getting trouble reclaiming, start doing writepage
+ * even in laptop mode.
+ */
+ if (sc.priority < DEF_PRIORITY - 2)
+ sc.may_writepage = 1;
+
+ /*
* Now scan the zone in the dma->highmem direction, stopping
* at the last zone which needs scanning.
*
@@ -2716,8 +2988,6 @@ loop_again:
*/
for (i = 0; i <= end_zone; i++) {
struct zone *zone = pgdat->node_zones + i;
- int nr_slab, testorder;
- unsigned long balance_gap;
if (!populated_zone(zone))
continue;
@@ -2738,65 +3008,14 @@ loop_again:
sc.nr_reclaimed += nr_soft_reclaimed;
/*
- * We put equal pressure on every zone, unless
- * one zone has way too many pages free
- * already. The "too many pages" is defined
- * as the high wmark plus a "gap" where the
- * gap is either the low watermark or 1%
- * of the zone, whichever is smaller.
+ * There should be no need to raise the scanning
+ * priority if enough pages are already being scanned
+ * that that high watermark would be met at 100%
+ * efficiency.
*/
- balance_gap = min(low_wmark_pages(zone),
- (zone->managed_pages +
- KSWAPD_ZONE_BALANCE_GAP_RATIO-1) /
- KSWAPD_ZONE_BALANCE_GAP_RATIO);
- /*
- * Kswapd reclaims only single pages with compaction
- * enabled. Trying too hard to reclaim until contiguous
- * free pages have become available can hurt performance
- * by evicting too much useful data from memory.
- * Do not reclaim more than needed for compaction.
- */
- testorder = order;
- if (IS_ENABLED(CONFIG_COMPACTION) && order &&
- compaction_suitable(zone, order) !=
- COMPACT_SKIPPED)
- testorder = 0;
-
- if ((buffer_heads_over_limit && is_highmem_idx(i)) ||
- !zone_balanced(zone, testorder,
- balance_gap, end_zone)) {
- shrink_zone(zone, &sc);
-
- reclaim_state->reclaimed_slab = 0;
- nr_slab = shrink_slab(&shrink, sc.nr_scanned, lru_pages);
- sc.nr_reclaimed += reclaim_state->reclaimed_slab;
-
- if (nr_slab == 0 && !zone_reclaimable(zone))
- zone->all_unreclaimable = 1;
- }
-
- /*
- * If we're getting trouble reclaiming, start doing
- * writepage even in laptop mode.
- */
- if (sc.priority < DEF_PRIORITY - 2)
- sc.may_writepage = 1;
-
- if (zone->all_unreclaimable) {
- if (end_zone && end_zone == i)
- end_zone--;
- continue;
- }
-
- if (zone_balanced(zone, testorder, 0, end_zone))
- /*
- * If a zone reaches its high watermark,
- * consider it to be no longer congested. It's
- * possible there are dirty pages backed by
- * congested BDIs but as pressure is relieved,
- * speculatively avoid congestion waits
- */
- zone_clear_flag(zone, ZONE_CONGESTED);
+ if (kswapd_shrink_zone(zone, end_zone, &sc,
+ lru_pages, &nr_attempted))
+ raise_priority = false;
}
/*
@@ -2808,74 +3027,38 @@ loop_again:
pfmemalloc_watermark_ok(pgdat))
wake_up(&pgdat->pfmemalloc_wait);
- if (pgdat_balanced(pgdat, order, *classzone_idx)) {
- pgdat_is_balanced = true;
- break; /* kswapd: all done */
- }
-
/*
- * We do this so kswapd doesn't build up large priorities for
- * example when it is freeing in parallel with allocators. It
- * matches the direct reclaim path behaviour in terms of impact
- * on zone->*_priority.
+ * Fragmentation may mean that the system cannot be rebalanced
+ * for high-order allocations in all zones. If twice the
+ * allocation size has been reclaimed and the zones are still
+ * not balanced then recheck the watermarks at order-0 to
+ * prevent kswapd reclaiming excessively. Assume that a
+ * process requested a high-order can direct reclaim/compact.
*/
- if (sc.nr_reclaimed >= SWAP_CLUSTER_MAX)
- break;
- } while (--sc.priority >= 0);
-
-out:
- if (!pgdat_is_balanced) {
- cond_resched();
+ if (order && sc.nr_reclaimed >= 2UL << order)
+ order = sc.order = 0;
- try_to_freeze();
+ /* Check if kswapd should be suspending */
+ if (try_to_freeze() || kthread_should_stop())
+ break;
/*
- * Fragmentation may mean that the system cannot be
- * rebalanced for high-order allocations in all zones.
- * At this point, if nr_reclaimed < SWAP_CLUSTER_MAX,
- * it means the zones have been fully scanned and are still
- * not balanced. For high-order allocations, there is
- * little point trying all over again as kswapd may
- * infinite loop.
- *
- * Instead, recheck all watermarks at order-0 as they
- * are the most important. If watermarks are ok, kswapd will go
- * back to sleep. High-order users can still perform direct
- * reclaim if they wish.
+ * Compact if necessary and kswapd is reclaiming at least the
+ * high watermark number of pages as requsted
*/
- if (sc.nr_reclaimed < SWAP_CLUSTER_MAX)
- order = sc.order = 0;
-
- goto loop_again;
- }
-
- /*
- * If kswapd was reclaiming at a higher order, it has the option of
- * sleeping without all zones being balanced. Before it does, it must
- * ensure that the watermarks for order-0 on *all* zones are met and
- * that the congestion flags are cleared. The congestion flag must
- * be cleared as kswapd is the only mechanism that clears the flag
- * and it is potentially going to sleep here.
- */
- if (order) {
- int zones_need_compaction = 1;
-
- for (i = 0; i <= end_zone; i++) {
- struct zone *zone = pgdat->node_zones + i;
-
- if (!populated_zone(zone))
- continue;
-
- /* Check if the memory needs to be defragmented. */
- if (zone_watermark_ok(zone, order,
- low_wmark_pages(zone), *classzone_idx, 0))
- zones_need_compaction = 0;
- }
-
- if (zones_need_compaction)
+ if (pgdat_needs_compaction && sc.nr_reclaimed > nr_attempted)
compact_pgdat(pgdat, order);
- }
+ /*
+ * Raise priority if scanning rate is too low or there was no
+ * progress in reclaiming pages
+ */
+ if (raise_priority || !sc.nr_reclaimed)
+ sc.priority--;
+ } while (sc.priority >= 1 &&
+ !pgdat_balanced(pgdat, order, *classzone_idx));
+
+out:
/*
* Return the order we were reclaiming at so prepare_kswapd_sleep()
* makes a decision on the order we were last reclaiming at. However,
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-17 08:15:05 +0000