{
struct rmap_item *rmap_item;
- rmap_item = kmem_cache_zalloc(rmap_item_cache, GFP_KERNEL);
+ rmap_item = kmem_cache_zalloc(rmap_item_cache, GFP_KERNEL |
+ __GFP_NORETRY | __GFP_NOWARN);
if (rmap_item)
ksm_rmap_items++;
return rmap_item;
else
ret = VM_FAULT_WRITE;
put_page(page);
- } while (!(ret & (VM_FAULT_WRITE | VM_FAULT_SIGBUS | VM_FAULT_OOM)));
+ } while (!(ret & (VM_FAULT_WRITE | VM_FAULT_SIGBUS | VM_FAULT_SIGSEGV | VM_FAULT_OOM)));
/*
* We must loop because handle_mm_fault() may back out if there's
* any difficulty e.g. if pte accessed bit gets updated concurrently.
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.
flush_dcache_page(page);
} else {
put_page(page);
-out: page = NULL;
+out:
+ page = NULL;
}
up_read(&mm->mmap_sem);
return page;
expected_mapping = (void *)stable_node +
(PAGE_MAPPING_ANON | PAGE_MAPPING_KSM);
again:
- kpfn = ACCESS_ONCE(stable_node->kpfn);
+ kpfn = READ_ONCE(stable_node->kpfn);
page = pfn_to_page(kpfn);
/*
* but on Alpha we need to be more careful.
*/
smp_read_barrier_depends();
- if (ACCESS_ONCE(page->mapping) != expected_mapping)
+ if (READ_ONCE(page->mapping) != expected_mapping)
goto stale;
/*
cpu_relax();
}
- if (ACCESS_ONCE(page->mapping) != expected_mapping) {
+ if (READ_ONCE(page->mapping) != expected_mapping) {
put_page(page);
goto stale;
}
if (lock_it) {
lock_page(page);
- if (ACCESS_ONCE(page->mapping) != expected_mapping) {
+ if (READ_ONCE(page->mapping) != expected_mapping) {
unlock_page(page);
put_page(page);
goto stale;
* before checking whether node->kpfn has been changed.
*/
smp_rmb();
- if (ACCESS_ONCE(stable_node->kpfn) != kpfn)
+ if (READ_ONCE(stable_node->kpfn) != kpfn)
goto again;
remove_node_from_stable_tree(stable_node);
return NULL;
unlock_page(page);
put_page(page);
- if (stable_node->hlist.first)
+ if (!hlist_empty(&stable_node->hlist))
ksm_pages_sharing--;
else
ksm_pages_shared--;
* this assure us that no O_DIRECT can happen after the check
* or in the middle of the check.
*/
- entry = ptep_clear_flush(vma, addr, ptep);
+ entry = ptep_clear_flush_notify(vma, addr, ptep);
/*
* Check that no O_DIRECT or similar I/O is in progress on the
* page
pmd = mm_find_pmd(mm, addr);
if (!pmd)
goto out;
- BUG_ON(pmd_trans_huge(*pmd));
mmun_start = addr;
mmun_end = addr + PAGE_SIZE;
page_add_anon_rmap(kpage, vma, addr);
flush_cache_page(vma, addr, pte_pfn(*ptep));
- ptep_clear_flush(vma, addr, ptep);
+ ptep_clear_flush_notify(vma, addr, ptep);
set_pte_at_notify(mm, addr, ptep, mk_pte(kpage, vma->vm_page_prot));
page_remove_rmap(page);
if (page == kpage) /* ksm page forked */
return 0;
- if (!(vma->vm_flags & VM_MERGEABLE))
- goto out;
if (PageTransCompound(page) && page_trans_compound_anon_split(page))
goto out;
BUG_ON(PageTransCompound(page));
int err = -EFAULT;
down_read(&mm->mmap_sem);
- if (ksm_test_exit(mm))
- goto out;
- vma = find_vma(mm, rmap_item->address);
- if (!vma || vma->vm_start > rmap_item->address)
+ vma = find_mergeable_vma(mm, rmap_item->address);
+ if (!vma)
goto out;
err = try_to_merge_one_page(vma, page, kpage);
cond_resched();
stable_node = rb_entry(*new, struct stable_node, node);
tree_page = get_ksm_page(stable_node, false);
- if (!tree_page)
- return NULL;
+ if (!tree_page) {
+ /*
+ * If we walked over a stale stable_node,
+ * get_ksm_page() will call rb_erase() and it
+ * may rebalance the tree from under us. So
+ * restart the search from scratch. Returning
+ * NULL would be safe too, but we'd generate
+ * false negative insertions just because some
+ * stable_node was stale.
+ */
+ goto again;
+ }
ret = memcmp_pages(page, tree_page);
put_page(tree_page);
unsigned long kpfn;
struct rb_root *root;
struct rb_node **new;
- struct rb_node *parent = NULL;
+ struct rb_node *parent;
struct stable_node *stable_node;
kpfn = page_to_pfn(kpage);
nid = get_kpfn_nid(kpfn);
root = root_stable_tree + nid;
+again:
+ parent = NULL;
new = &root->rb_node;
while (*new) {
cond_resched();
stable_node = rb_entry(*new, struct stable_node, node);
tree_page = get_ksm_page(stable_node, false);
- if (!tree_page)
- return NULL;
+ if (!tree_page) {
+ /*
+ * If we walked over a stale stable_node,
+ * get_ksm_page() will call rb_erase() and it
+ * may rebalance the tree from under us. So
+ * restart the search from scratch. Returning
+ * NULL would be safe too, but we'd generate
+ * false negative insertions just because some
+ * stable_node was stale.
+ */
+ goto again;
+ }
ret = memcmp_pages(kpage, tree_page);
put_page(tree_page);
cond_resched();
tree_rmap_item = rb_entry(*new, struct rmap_item, node);
tree_page = get_mergeable_page(tree_rmap_item);
- if (IS_ERR_OR_NULL(tree_page))
+ if (!tree_page)
return NULL;
/*
*/
if (*vm_flags & (VM_MERGEABLE | VM_SHARED | VM_MAYSHARE |
VM_PFNMAP | VM_IO | VM_DONTEXPAND |
- VM_HUGETLB | VM_NONLINEAR | VM_MIXEDMAP))
+ VM_HUGETLB | VM_MIXEDMAP))
return 0; /* just ignore the advice */
#ifdef VM_SAO
return new_page;
}
-int page_referenced_ksm(struct page *page, struct mem_cgroup *memcg,
- unsigned long *vm_flags)
+int rmap_walk_ksm(struct page *page, struct rmap_walk_control *rwc)
{
struct stable_node *stable_node;
struct rmap_item *rmap_item;
- unsigned int mapcount = page_mapcount(page);
- int referenced = 0;
+ int ret = SWAP_AGAIN;
int search_new_forks = 0;
- VM_BUG_ON(!PageKsm(page));
- VM_BUG_ON(!PageLocked(page));
+ VM_BUG_ON_PAGE(!PageKsm(page), page);
+
+ /*
+ * Rely on the page lock to protect against concurrent modifications
+ * to that page's node of the stable tree.
+ */
+ VM_BUG_ON_PAGE(!PageLocked(page), page);
stable_node = page_stable_node(page);
if (!stable_node)
- return 0;
+ return ret;
again:
hlist_for_each_entry(rmap_item, &stable_node->hlist, hlist) {
struct anon_vma *anon_vma = rmap_item->anon_vma;
struct anon_vma_chain *vmac;
struct vm_area_struct *vma;
+ cond_resched();
anon_vma_lock_read(anon_vma);
anon_vma_interval_tree_foreach(vmac, &anon_vma->rb_root,
0, ULONG_MAX) {
+ cond_resched();
vma = vmac->vma;
if (rmap_item->address < vma->vm_start ||
rmap_item->address >= vma->vm_end)
if ((rmap_item->mm == vma->vm_mm) == search_new_forks)
continue;
- if (memcg && !mm_match_cgroup(vma->vm_mm, memcg))
+ if (rwc->invalid_vma && rwc->invalid_vma(vma, rwc->arg))
continue;
- referenced += page_referenced_one(page, vma,
- rmap_item->address, &mapcount, vm_flags);
- if (!search_new_forks || !mapcount)
- break;
- }
- anon_vma_unlock_read(anon_vma);
- if (!mapcount)
- goto out;
- }
- if (!search_new_forks++)
- goto again;
-out:
- return referenced;
-}
-
-int try_to_unmap_ksm(struct page *page, enum ttu_flags flags)
-{
- struct stable_node *stable_node;
- struct rmap_item *rmap_item;
- int ret = SWAP_AGAIN;
- int search_new_forks = 0;
-
- VM_BUG_ON(!PageKsm(page));
- VM_BUG_ON(!PageLocked(page));
-
- stable_node = page_stable_node(page);
- if (!stable_node)
- return SWAP_FAIL;
-again:
- hlist_for_each_entry(rmap_item, &stable_node->hlist, hlist) {
- struct anon_vma *anon_vma = rmap_item->anon_vma;
- struct anon_vma_chain *vmac;
- struct vm_area_struct *vma;
-
- anon_vma_lock_read(anon_vma);
- anon_vma_interval_tree_foreach(vmac, &anon_vma->rb_root,
- 0, ULONG_MAX) {
- vma = vmac->vma;
- if (rmap_item->address < vma->vm_start ||
- rmap_item->address >= vma->vm_end)
- continue;
- /*
- * Initially we examine only the vma which covers this
- * rmap_item; but later, if there is still work to do,
- * we examine covering vmas in other mms: in case they
- * were forked from the original since ksmd passed.
- */
- if ((rmap_item->mm == vma->vm_mm) == search_new_forks)
- continue;
-
- ret = try_to_unmap_one(page, vma,
- rmap_item->address, flags);
- if (ret != SWAP_AGAIN || !page_mapped(page)) {
+ ret = rwc->rmap_one(page, vma,
+ rmap_item->address, rwc->arg);
+ if (ret != SWAP_AGAIN) {
anon_vma_unlock_read(anon_vma);
goto out;
}
- }
- anon_vma_unlock_read(anon_vma);
- }
- if (!search_new_forks++)
- goto again;
-out:
- return ret;
-}
-
-#ifdef CONFIG_MIGRATION
-int rmap_walk_ksm(struct page *page, int (*rmap_one)(struct page *,
- struct vm_area_struct *, unsigned long, void *), void *arg)
-{
- struct stable_node *stable_node;
- struct rmap_item *rmap_item;
- int ret = SWAP_AGAIN;
- int search_new_forks = 0;
-
- VM_BUG_ON(!PageKsm(page));
- VM_BUG_ON(!PageLocked(page));
-
- stable_node = page_stable_node(page);
- if (!stable_node)
- return ret;
-again:
- hlist_for_each_entry(rmap_item, &stable_node->hlist, hlist) {
- struct anon_vma *anon_vma = rmap_item->anon_vma;
- struct anon_vma_chain *vmac;
- struct vm_area_struct *vma;
-
- anon_vma_lock_read(anon_vma);
- anon_vma_interval_tree_foreach(vmac, &anon_vma->rb_root,
- 0, ULONG_MAX) {
- vma = vmac->vma;
- if (rmap_item->address < vma->vm_start ||
- rmap_item->address >= vma->vm_end)
- continue;
- /*
- * Initially we examine only the vma which covers this
- * rmap_item; but later, if there is still work to do,
- * we examine covering vmas in other mms: in case they
- * were forked from the original since ksmd passed.
- */
- if ((rmap_item->mm == vma->vm_mm) == search_new_forks)
- continue;
-
- ret = rmap_one(page, vma, rmap_item->address, arg);
- if (ret != SWAP_AGAIN) {
+ if (rwc->done && rwc->done(page)) {
anon_vma_unlock_read(anon_vma);
goto out;
}
return ret;
}
+#ifdef CONFIG_MIGRATION
void ksm_migrate_page(struct page *newpage, struct page *oldpage)
{
struct stable_node *stable_node;
- VM_BUG_ON(!PageLocked(oldpage));
- VM_BUG_ON(!PageLocked(newpage));
- VM_BUG_ON(newpage->mapping != oldpage->mapping);
+ VM_BUG_ON_PAGE(!PageLocked(oldpage), oldpage);
+ VM_BUG_ON_PAGE(!PageLocked(newpage), newpage);
+ VM_BUG_ON_PAGE(newpage->mapping != oldpage->mapping, newpage);
stable_node = page_stable_node(newpage);
if (stable_node) {
- VM_BUG_ON(stable_node->kpfn != page_to_pfn(oldpage));
+ VM_BUG_ON_PAGE(stable_node->kpfn != page_to_pfn(oldpage), oldpage);
stable_node->kpfn = page_to_pfn(newpage);
/*
* newpage->mapping was set in advance; now we need smp_wmb()
#endif /* CONFIG_MIGRATION */
#ifdef CONFIG_MEMORY_HOTREMOVE
-static int just_wait(void *word)
-{
- schedule();
- return 0;
-}
-
static void wait_while_offlining(void)
{
while (ksm_run & KSM_RUN_OFFLINE) {
mutex_unlock(&ksm_thread_mutex);
wait_on_bit(&ksm_run, ilog2(KSM_RUN_OFFLINE),
- just_wait, TASK_UNINTERRUPTIBLE);
+ TASK_UNINTERRUPTIBLE);
mutex_lock(&ksm_thread_mutex);
}
}
unsigned long msecs;
int err;
- err = strict_strtoul(buf, 10, &msecs);
+ err = kstrtoul(buf, 10, &msecs);
if (err || msecs > UINT_MAX)
return -EINVAL;
int err;
unsigned long nr_pages;
- err = strict_strtoul(buf, 10, &nr_pages);
+ err = kstrtoul(buf, 10, &nr_pages);
if (err || nr_pages > UINT_MAX)
return -EINVAL;
int err;
unsigned long flags;
- err = strict_strtoul(buf, 10, &flags);
+ err = kstrtoul(buf, 10, &flags);
if (err || flags > UINT_MAX)
return -EINVAL;
if (flags > KSM_RUN_UNMERGE)
* Allocate stable and unstable together:
* MAXSMP NODES_SHIFT 10 will use 16kB.
*/
- buf = kcalloc(nr_node_ids + nr_node_ids,
- sizeof(*buf), GFP_KERNEL | __GFP_ZERO);
+ buf = kcalloc(nr_node_ids + nr_node_ids, sizeof(*buf),
+ GFP_KERNEL);
/* Let us assume that RB_ROOT is NULL is zero */
if (!buf)
err = -ENOMEM;
ksm_thread = kthread_run(ksm_scan_thread, NULL, "ksmd");
if (IS_ERR(ksm_thread)) {
- printk(KERN_ERR "ksm: creating kthread failed\n");
+ pr_err("ksm: creating kthread failed\n");
err = PTR_ERR(ksm_thread);
goto out_free;
}
#ifdef CONFIG_SYSFS
err = sysfs_create_group(mm_kobj, &ksm_attr_group);
if (err) {
- printk(KERN_ERR "ksm: register sysfs failed\n");
+ pr_err("ksm: register sysfs failed\n");
kthread_stop(ksm_thread);
goto out_free;
}
out:
return err;
}
-module_init(ksm_init)
+subsys_initcall(ksm_init);
projects / firefly-linux-kernel-4.4.55.git / blobdiff