}
__setup("transparent_hugepage=", setup_transparent_hugepage);
-static inline pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma)
+pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma)
{
if (likely(vma->vm_flags & VM_WRITE))
pmd = pmd_mkwrite(pmd);
int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
unsigned long addr, pmd_t pmd, pmd_t *pmdp)
{
- struct page *page = NULL;
+ struct page *page;
unsigned long haddr = addr & HPAGE_PMD_MASK;
int target_nid;
int current_nid = -1;
+ bool migrated;
+ bool page_locked = false;
spin_lock(&mm->page_table_lock);
if (unlikely(!pmd_same(pmd, *pmdp)))
page = pmd_page(pmd);
get_page(page);
- spin_unlock(&mm->page_table_lock);
current_nid = page_to_nid(page);
count_vm_numa_event(NUMA_HINT_FAULTS);
if (current_nid == numa_node_id())
count_vm_numa_event(NUMA_HINT_FAULTS_LOCAL);
target_nid = mpol_misplaced(page, vma, haddr);
- if (target_nid == -1)
+ if (target_nid == -1) {
+ put_page(page);
goto clear_pmdnuma;
+ }
- /*
- * Due to lacking code to migrate thp pages, we'll split
- * (which preserves the special PROT_NONE) and re-take the
- * fault on the normal pages.
- */
- split_huge_page(page);
- put_page(page);
-
- return 0;
+ /* Acquire the page lock to serialise THP migrations */
+ spin_unlock(&mm->page_table_lock);
+ lock_page(page);
+ page_locked = true;
-clear_pmdnuma:
+ /* Confirm the PTE did not while locked */
spin_lock(&mm->page_table_lock);
- if (unlikely(!pmd_same(pmd, *pmdp)))
+ if (unlikely(!pmd_same(pmd, *pmdp))) {
+ unlock_page(page);
+ put_page(page);
goto out_unlock;
+ }
+ spin_unlock(&mm->page_table_lock);
+
+ /* Migrate the THP to the requested node */
+ migrated = migrate_misplaced_transhuge_page(mm, vma,
+ pmdp, pmd, addr,
+ page, target_nid);
+ if (migrated)
+ current_nid = target_nid;
+ else {
+ spin_lock(&mm->page_table_lock);
+ if (unlikely(!pmd_same(pmd, *pmdp))) {
+ unlock_page(page);
+ goto out_unlock;
+ }
+ goto clear_pmdnuma;
+ }
+
+ task_numa_fault(current_nid, HPAGE_PMD_NR, migrated);
+ return 0;
+clear_pmdnuma:
pmd = pmd_mknonnuma(pmd);
set_pmd_at(mm, haddr, pmdp, pmd);
VM_BUG_ON(pmd_numa(*pmdp));
update_mmu_cache_pmd(vma, addr, pmdp);
+ if (page_locked)
+ unlock_page(page);
out_unlock:
spin_unlock(&mm->page_table_lock);
- if (page) {
- put_page(page);
- task_numa_fault(numa_node_id(), HPAGE_PMD_NR, false);
- }
+ if (current_nid != -1)
+ task_numa_fault(current_nid, HPAGE_PMD_NR, migrated);
return 0;
}
*/
void migrate_page_copy(struct page *newpage, struct page *page)
{
- if (PageHuge(page))
+ if (PageHuge(page) || PageTransHuge(page))
copy_huge_page(newpage, page);
else
copy_highpage(newpage, page);
return true;
}
-/*
- * Attempt to migrate a misplaced page to the specified destination
- * node. Caller is expected to have an elevated reference count on
- * the page that will be dropped by this function before returning.
- */
-int migrate_misplaced_page(struct page *page, int node)
+/* Returns true if the node is migrate rate-limited after the update */
+bool numamigrate_update_ratelimit(pg_data_t *pgdat)
{
- pg_data_t *pgdat = NODE_DATA(node);
- int isolated = 0;
- LIST_HEAD(migratepages);
-
- /*
- * Don't migrate pages that are mapped in multiple processes.
- * TODO: Handle false sharing detection instead of this hammer
- */
- if (page_mapcount(page) != 1) {
- put_page(page);
- goto out;
- }
+ bool rate_limited = false;
/*
* Rate-limit the amount of data that is being migrated to a node.
pgdat->numabalancing_migrate_next_window = jiffies +
msecs_to_jiffies(migrate_interval_millisecs);
}
- if (pgdat->numabalancing_migrate_nr_pages > ratelimit_pages) {
- spin_unlock(&pgdat->numabalancing_migrate_lock);
- put_page(page);
- goto out;
- }
- pgdat->numabalancing_migrate_nr_pages++;
+ if (pgdat->numabalancing_migrate_nr_pages > ratelimit_pages)
+ rate_limited = true;
+ else
+ pgdat->numabalancing_migrate_nr_pages++;
spin_unlock(&pgdat->numabalancing_migrate_lock);
+
+ return rate_limited;
+}
+
+int numamigrate_isolate_page(pg_data_t *pgdat, struct page *page)
+{
+ int ret = 0;
/* Avoid migrating to a node that is nearly full */
if (migrate_balanced_pgdat(pgdat, 1)) {
if (isolate_lru_page(page)) {
put_page(page);
- goto out;
+ return 0;
}
- isolated = 1;
+ /* Page is isolated */
+ ret = 1;
page_lru = page_is_file_cache(page);
- inc_zone_page_state(page, NR_ISOLATED_ANON + page_lru);
- list_add(&page->lru, &migratepages);
+ if (!PageTransHuge(page))
+ inc_zone_page_state(page, NR_ISOLATED_ANON + page_lru);
+ else
+ mod_zone_page_state(page_zone(page),
+ NR_ISOLATED_ANON + page_lru,
+ HPAGE_PMD_NR);
}
/*
*/
put_page(page);
- if (isolated) {
- int nr_remaining;
-
- nr_remaining = migrate_pages(&migratepages,
- alloc_misplaced_dst_page,
- node, false, MIGRATE_ASYNC,
- MR_NUMA_MISPLACED);
- if (nr_remaining) {
- putback_lru_pages(&migratepages);
- isolated = 0;
- } else
- count_vm_numa_event(NUMA_PAGE_MIGRATE);
+ return ret;
+}
+
+/*
+ * Attempt to migrate a misplaced page to the specified destination
+ * node. Caller is expected to have an elevated reference count on
+ * the page that will be dropped by this function before returning.
+ */
+int migrate_misplaced_page(struct page *page, int node)
+{
+ pg_data_t *pgdat = NODE_DATA(node);
+ int isolated = 0;
+ int nr_remaining;
+ LIST_HEAD(migratepages);
+
+ /*
+ * Don't migrate pages that are mapped in multiple processes.
+ * TODO: Handle false sharing detection instead of this hammer
+ */
+ if (page_mapcount(page) != 1) {
+ put_page(page);
+ goto out;
}
+
+ /*
+ * Rate-limit the amount of data that is being migrated to a node.
+ * Optimal placement is no good if the memory bus is saturated and
+ * all the time is being spent migrating!
+ */
+ if (numamigrate_update_ratelimit(pgdat)) {
+ put_page(page);
+ goto out;
+ }
+
+ isolated = numamigrate_isolate_page(pgdat, page);
+ if (!isolated)
+ goto out;
+
+ list_add(&page->lru, &migratepages);
+ nr_remaining = migrate_pages(&migratepages,
+ alloc_misplaced_dst_page,
+ node, false, MIGRATE_ASYNC,
+ MR_NUMA_MISPLACED);
+ if (nr_remaining) {
+ putback_lru_pages(&migratepages);
+ isolated = 0;
+ } else
+ count_vm_numa_event(NUMA_PAGE_MIGRATE);
BUG_ON(!list_empty(&migratepages));
out:
return isolated;
}
+
+int migrate_misplaced_transhuge_page(struct mm_struct *mm,
+ struct vm_area_struct *vma,
+ pmd_t *pmd, pmd_t entry,
+ unsigned long address,
+ struct page *page, int node)
+{
+ unsigned long haddr = address & HPAGE_PMD_MASK;
+ pg_data_t *pgdat = NODE_DATA(node);
+ int isolated = 0;
+ struct page *new_page = NULL;
+ struct mem_cgroup *memcg = NULL;
+ int page_lru = page_is_file_cache(page);
+
+ /*
+ * Don't migrate pages that are mapped in multiple processes.
+ * TODO: Handle false sharing detection instead of this hammer
+ */
+ if (page_mapcount(page) != 1)
+ goto out_dropref;
+
+ /*
+ * Rate-limit the amount of data that is being migrated to a node.
+ * Optimal placement is no good if the memory bus is saturated and
+ * all the time is being spent migrating!
+ */
+ if (numamigrate_update_ratelimit(pgdat))
+ goto out_dropref;
+
+ new_page = alloc_pages_node(node,
+ (GFP_TRANSHUGE | GFP_THISNODE) & ~__GFP_WAIT, HPAGE_PMD_ORDER);
+ if (!new_page)
+ goto out_dropref;
+ page_xchg_last_nid(new_page, page_last_nid(page));
+
+ isolated = numamigrate_isolate_page(pgdat, page);
+ if (!isolated) {
+ put_page(new_page);
+ goto out_keep_locked;
+ }
+
+ /* Prepare a page as a migration target */
+ __set_page_locked(new_page);
+ SetPageSwapBacked(new_page);
+
+ /* anon mapping, we can simply copy page->mapping to the new page: */
+ new_page->mapping = page->mapping;
+ new_page->index = page->index;
+ migrate_page_copy(new_page, page);
+ WARN_ON(PageLRU(new_page));
+
+ /* Recheck the target PMD */
+ spin_lock(&mm->page_table_lock);
+ if (unlikely(!pmd_same(*pmd, entry))) {
+ spin_unlock(&mm->page_table_lock);
+
+ /* Reverse changes made by migrate_page_copy() */
+ if (TestClearPageActive(new_page))
+ SetPageActive(page);
+ if (TestClearPageUnevictable(new_page))
+ SetPageUnevictable(page);
+ mlock_migrate_page(page, new_page);
+
+ unlock_page(new_page);
+ put_page(new_page); /* Free it */
+
+ unlock_page(page);
+ putback_lru_page(page);
+
+ count_vm_events(PGMIGRATE_FAIL, HPAGE_PMD_NR);
+ goto out;
+ }
+
+ /*
+ * Traditional migration needs to prepare the memcg charge
+ * transaction early to prevent the old page from being
+ * uncharged when installing migration entries. Here we can
+ * save the potential rollback and start the charge transfer
+ * only when migration is already known to end successfully.
+ */
+ mem_cgroup_prepare_migration(page, new_page, &memcg);
+
+ entry = mk_pmd(new_page, vma->vm_page_prot);
+ entry = pmd_mknonnuma(entry);
+ entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma);
+ entry = pmd_mkhuge(entry);
+
+ page_add_new_anon_rmap(new_page, vma, haddr);
+
+ set_pmd_at(mm, haddr, pmd, entry);
+ update_mmu_cache_pmd(vma, address, entry);
+ page_remove_rmap(page);
+ /*
+ * Finish the charge transaction under the page table lock to
+ * prevent split_huge_page() from dividing up the charge
+ * before it's fully transferred to the new page.
+ */
+ mem_cgroup_end_migration(memcg, page, new_page, true);
+ spin_unlock(&mm->page_table_lock);
+
+ unlock_page(new_page);
+ unlock_page(page);
+ put_page(page); /* Drop the rmap reference */
+ put_page(page); /* Drop the LRU isolation reference */
+
+ count_vm_events(PGMIGRATE_SUCCESS, HPAGE_PMD_NR);
+ count_vm_numa_events(NUMA_PAGE_MIGRATE, HPAGE_PMD_NR);
+
+out:
+ mod_zone_page_state(page_zone(page),
+ NR_ISOLATED_ANON + page_lru,
+ -HPAGE_PMD_NR);
+ return isolated;
+
+out_dropref:
+ put_page(page);
+out_keep_locked:
+ return 0;
+}
#endif /* CONFIG_NUMA_BALANCING */
#endif /* CONFIG_NUMA */
projects / openwrt / staging / blogic.git / commitdiff