unsigned long nr_mapped; /* From page_state */
- /* How many pages shrink_cache() should reclaim */
- int nr_to_reclaim;
-
/* Ask shrink_caches, or shrink_zone to scan at this priority */
unsigned int priority;
*
* Returns the number of slab objects which we shrunk.
*/
-static int shrink_slab(unsigned long scanned, gfp_t gfp_mask,
- unsigned long lru_pages)
+int shrink_slab(unsigned long scanned, gfp_t gfp_mask, unsigned long lru_pages)
{
struct shrinker *shrinker;
int ret = 0;
list_for_each_entry(shrinker, &shrinker_list, list) {
unsigned long long delta;
unsigned long total_scan;
+ unsigned long max_pass = (*shrinker->shrinker)(0, gfp_mask);
delta = (4 * scanned) / shrinker->seeks;
- delta *= (*shrinker->shrinker)(0, gfp_mask);
+ delta *= max_pass;
do_div(delta, lru_pages + 1);
shrinker->nr += delta;
- if (shrinker->nr < 0)
- shrinker->nr = LONG_MAX; /* It wrapped! */
+ if (shrinker->nr < 0) {
+ printk(KERN_ERR "%s: nr=%ld\n",
+ __FUNCTION__, shrinker->nr);
+ shrinker->nr = max_pass;
+ }
+
+ /*
+ * Avoid risking looping forever due to too large nr value:
+ * never try to free more than twice the estimate number of
+ * freeable entries.
+ */
+ if (shrinker->nr > max_pass * 2)
+ shrinker->nr = max_pass * 2;
total_scan = shrinker->nr;
shrinker->nr = 0;
static int may_write_to_queue(struct backing_dev_info *bdi)
{
- if (current_is_kswapd())
- return 1;
- if (current_is_pdflush()) /* This is unlikely, but why not... */
+ if (current->flags & PF_SWAPWRITE)
return 1;
if (!bdi_write_congested(bdi))
return 1;
res = mapping->a_ops->writepage(page, &wbc);
if (res < 0)
handle_write_error(mapping, page, res);
- if (res == WRITEPAGE_ACTIVATE) {
+ if (res == AOP_WRITEPAGE_ACTIVATE) {
ClearPageReclaim(page);
return PAGE_ACTIVATE;
}
return PAGE_CLEAN;
}
+static int remove_mapping(struct address_space *mapping, struct page *page)
+{
+ if (!mapping)
+ return 0; /* truncate got there first */
+
+ write_lock_irq(&mapping->tree_lock);
+
+ /*
+ * The non-racy check for busy page. It is critical to check
+ * PageDirty _after_ making sure that the page is freeable and
+ * not in use by anybody. (pagecache + us == 2)
+ */
+ if (unlikely(page_count(page) != 2))
+ goto cannot_free;
+ smp_rmb();
+ if (unlikely(PageDirty(page)))
+ goto cannot_free;
+
+ if (PageSwapCache(page)) {
+ swp_entry_t swap = { .val = page_private(page) };
+ __delete_from_swap_cache(page);
+ write_unlock_irq(&mapping->tree_lock);
+ swap_free(swap);
+ __put_page(page); /* The pagecache ref */
+ return 1;
+ }
+
+ __remove_from_page_cache(page);
+ write_unlock_irq(&mapping->tree_lock);
+ __put_page(page);
+ return 1;
+
+cannot_free:
+ write_unlock_irq(&mapping->tree_lock);
+ return 0;
+}
+
/*
* shrink_list adds the number of reclaimed pages to sc->nr_reclaimed
*/
if (PageWriteback(page))
goto keep_locked;
- referenced = page_referenced(page, 1, sc->priority <= 0);
+ referenced = page_referenced(page, 1);
/* In active use or really unfreeable? Activate it. */
if (referenced && page_mapping_inuse(page))
goto activate_locked;
if (PageAnon(page) && !PageSwapCache(page)) {
if (!sc->may_swap)
goto keep_locked;
- if (!add_to_swap(page))
+ if (!add_to_swap(page, GFP_ATOMIC))
goto activate_locked;
}
#endif /* CONFIG_SWAP */
* processes. Try to unmap it here.
*/
if (page_mapped(page) && mapping) {
- switch (try_to_unmap(page)) {
+ /*
+ * No unmapping if we do not swap
+ */
+ if (!sc->may_swap)
+ goto keep_locked;
+
+ switch (try_to_unmap(page, 0)) {
case SWAP_FAIL:
goto activate_locked;
case SWAP_AGAIN:
goto keep_locked;
if (!may_enter_fs)
goto keep_locked;
- if (laptop_mode && !sc->may_writepage)
+ if (!sc->may_writepage)
goto keep_locked;
/* Page is dirty, try to write it out here */
goto free_it;
}
- if (!mapping)
- goto keep_locked; /* truncate got there first */
-
- write_lock_irq(&mapping->tree_lock);
-
- /*
- * The non-racy check for busy page. It is critical to check
- * PageDirty _after_ making sure that the page is freeable and
- * not in use by anybody. (pagecache + us == 2)
- */
- if (unlikely(page_count(page) != 2))
- goto cannot_free;
- smp_rmb();
- if (unlikely(PageDirty(page)))
- goto cannot_free;
-
-#ifdef CONFIG_SWAP
- if (PageSwapCache(page)) {
- swp_entry_t swap = { .val = page_private(page) };
- __delete_from_swap_cache(page);
- write_unlock_irq(&mapping->tree_lock);
- swap_free(swap);
- __put_page(page); /* The pagecache ref */
- goto free_it;
- }
-#endif /* CONFIG_SWAP */
-
- __remove_from_page_cache(page);
- write_unlock_irq(&mapping->tree_lock);
- __put_page(page);
+ if (!remove_mapping(mapping, page))
+ goto keep_locked;
free_it:
unlock_page(page);
__pagevec_release_nonlru(&freed_pvec);
continue;
-cannot_free:
- write_unlock_irq(&mapping->tree_lock);
- goto keep_locked;
-
activate_locked:
SetPageActive(page);
pgactivate++;
return reclaimed;
}
+#ifdef CONFIG_MIGRATION
+static inline void move_to_lru(struct page *page)
+{
+ list_del(&page->lru);
+ if (PageActive(page)) {
+ /*
+ * lru_cache_add_active checks that
+ * the PG_active bit is off.
+ */
+ ClearPageActive(page);
+ lru_cache_add_active(page);
+ } else {
+ lru_cache_add(page);
+ }
+ put_page(page);
+}
+
+/*
+ * Add isolated pages on the list back to the LRU.
+ *
+ * returns the number of pages put back.
+ */
+int putback_lru_pages(struct list_head *l)
+{
+ struct page *page;
+ struct page *page2;
+ int count = 0;
+
+ list_for_each_entry_safe(page, page2, l, lru) {
+ move_to_lru(page);
+ count++;
+ }
+ return count;
+}
+
+/*
+ * Non migratable page
+ */
+int fail_migrate_page(struct page *newpage, struct page *page)
+{
+ return -EIO;
+}
+EXPORT_SYMBOL(fail_migrate_page);
+
+/*
+ * swapout a single page
+ * page is locked upon entry, unlocked on exit
+ */
+static int swap_page(struct page *page)
+{
+ struct address_space *mapping = page_mapping(page);
+
+ if (page_mapped(page) && mapping)
+ if (try_to_unmap(page, 0) != SWAP_SUCCESS)
+ goto unlock_retry;
+
+ if (PageDirty(page)) {
+ /* Page is dirty, try to write it out here */
+ switch(pageout(page, mapping)) {
+ case PAGE_KEEP:
+ case PAGE_ACTIVATE:
+ goto unlock_retry;
+
+ case PAGE_SUCCESS:
+ goto retry;
+
+ case PAGE_CLEAN:
+ ; /* try to free the page below */
+ }
+ }
+
+ if (PagePrivate(page)) {
+ if (!try_to_release_page(page, GFP_KERNEL) ||
+ (!mapping && page_count(page) == 1))
+ goto unlock_retry;
+ }
+
+ if (remove_mapping(mapping, page)) {
+ /* Success */
+ unlock_page(page);
+ return 0;
+ }
+
+unlock_retry:
+ unlock_page(page);
+
+retry:
+ return -EAGAIN;
+}
+EXPORT_SYMBOL(swap_page);
+
+/*
+ * Page migration was first developed in the context of the memory hotplug
+ * project. The main authors of the migration code are:
+ *
+ * IWAMOTO Toshihiro <iwamoto@valinux.co.jp>
+ * Hirokazu Takahashi <taka@valinux.co.jp>
+ * Dave Hansen <haveblue@us.ibm.com>
+ * Christoph Lameter <clameter@sgi.com>
+ */
+
+/*
+ * Remove references for a page and establish the new page with the correct
+ * basic settings to be able to stop accesses to the page.
+ */
+int migrate_page_remove_references(struct page *newpage,
+ struct page *page, int nr_refs)
+{
+ struct address_space *mapping = page_mapping(page);
+ struct page **radix_pointer;
+
+ /*
+ * Avoid doing any of the following work if the page count
+ * indicates that the page is in use or truncate has removed
+ * the page.
+ */
+ if (!mapping || page_mapcount(page) + nr_refs != page_count(page))
+ return 1;
+
+ /*
+ * Establish swap ptes for anonymous pages or destroy pte
+ * maps for files.
+ *
+ * In order to reestablish file backed mappings the fault handlers
+ * will take the radix tree_lock which may then be used to stop
+ * processses from accessing this page until the new page is ready.
+ *
+ * A process accessing via a swap pte (an anonymous page) will take a
+ * page_lock on the old page which will block the process until the
+ * migration attempt is complete. At that time the PageSwapCache bit
+ * will be examined. If the page was migrated then the PageSwapCache
+ * bit will be clear and the operation to retrieve the page will be
+ * retried which will find the new page in the radix tree. Then a new
+ * direct mapping may be generated based on the radix tree contents.
+ *
+ * If the page was not migrated then the PageSwapCache bit
+ * is still set and the operation may continue.
+ */
+ try_to_unmap(page, 1);
+
+ /*
+ * Give up if we were unable to remove all mappings.
+ */
+ if (page_mapcount(page))
+ return 1;
+
+ write_lock_irq(&mapping->tree_lock);
+
+ radix_pointer = (struct page **)radix_tree_lookup_slot(
+ &mapping->page_tree,
+ page_index(page));
+
+ if (!page_mapping(page) || page_count(page) != nr_refs ||
+ *radix_pointer != page) {
+ write_unlock_irq(&mapping->tree_lock);
+ return 1;
+ }
+
+ /*
+ * Now we know that no one else is looking at the page.
+ *
+ * Certain minimal information about a page must be available
+ * in order for other subsystems to properly handle the page if they
+ * find it through the radix tree update before we are finished
+ * copying the page.
+ */
+ get_page(newpage);
+ newpage->index = page->index;
+ newpage->mapping = page->mapping;
+ if (PageSwapCache(page)) {
+ SetPageSwapCache(newpage);
+ set_page_private(newpage, page_private(page));
+ }
+
+ *radix_pointer = newpage;
+ __put_page(page);
+ write_unlock_irq(&mapping->tree_lock);
+
+ return 0;
+}
+EXPORT_SYMBOL(migrate_page_remove_references);
+
+/*
+ * Copy the page to its new location
+ */
+void migrate_page_copy(struct page *newpage, struct page *page)
+{
+ copy_highpage(newpage, page);
+
+ if (PageError(page))
+ SetPageError(newpage);
+ if (PageReferenced(page))
+ SetPageReferenced(newpage);
+ if (PageUptodate(page))
+ SetPageUptodate(newpage);
+ if (PageActive(page))
+ SetPageActive(newpage);
+ if (PageChecked(page))
+ SetPageChecked(newpage);
+ if (PageMappedToDisk(page))
+ SetPageMappedToDisk(newpage);
+
+ if (PageDirty(page)) {
+ clear_page_dirty_for_io(page);
+ set_page_dirty(newpage);
+ }
+
+ ClearPageSwapCache(page);
+ ClearPageActive(page);
+ ClearPagePrivate(page);
+ set_page_private(page, 0);
+ page->mapping = NULL;
+
+ /*
+ * If any waiters have accumulated on the new page then
+ * wake them up.
+ */
+ if (PageWriteback(newpage))
+ end_page_writeback(newpage);
+}
+EXPORT_SYMBOL(migrate_page_copy);
+
+/*
+ * Common logic to directly migrate a single page suitable for
+ * pages that do not use PagePrivate.
+ *
+ * Pages are locked upon entry and exit.
+ */
+int migrate_page(struct page *newpage, struct page *page)
+{
+ BUG_ON(PageWriteback(page)); /* Writeback must be complete */
+
+ if (migrate_page_remove_references(newpage, page, 2))
+ return -EAGAIN;
+
+ migrate_page_copy(newpage, page);
+
+ /*
+ * Remove auxiliary swap entries and replace
+ * them with real ptes.
+ *
+ * Note that a real pte entry will allow processes that are not
+ * waiting on the page lock to use the new page via the page tables
+ * before the new page is unlocked.
+ */
+ remove_from_swap(newpage);
+ return 0;
+}
+EXPORT_SYMBOL(migrate_page);
+
+/*
+ * migrate_pages
+ *
+ * Two lists are passed to this function. The first list
+ * contains the pages isolated from the LRU to be migrated.
+ * The second list contains new pages that the pages isolated
+ * can be moved to. If the second list is NULL then all
+ * pages are swapped out.
+ *
+ * The function returns after 10 attempts or if no pages
+ * are movable anymore because t has become empty
+ * or no retryable pages exist anymore.
+ *
+ * Return: Number of pages not migrated when "to" ran empty.
+ */
+int migrate_pages(struct list_head *from, struct list_head *to,
+ struct list_head *moved, struct list_head *failed)
+{
+ int retry;
+ int nr_failed = 0;
+ int pass = 0;
+ struct page *page;
+ struct page *page2;
+ int swapwrite = current->flags & PF_SWAPWRITE;
+ int rc;
+
+ if (!swapwrite)
+ current->flags |= PF_SWAPWRITE;
+
+redo:
+ retry = 0;
+
+ list_for_each_entry_safe(page, page2, from, lru) {
+ struct page *newpage = NULL;
+ struct address_space *mapping;
+
+ cond_resched();
+
+ rc = 0;
+ if (page_count(page) == 1)
+ /* page was freed from under us. So we are done. */
+ goto next;
+
+ if (to && list_empty(to))
+ break;
+
+ /*
+ * Skip locked pages during the first two passes to give the
+ * functions holding the lock time to release the page. Later we
+ * use lock_page() to have a higher chance of acquiring the
+ * lock.
+ */
+ rc = -EAGAIN;
+ if (pass > 2)
+ lock_page(page);
+ else
+ if (TestSetPageLocked(page))
+ goto next;
+
+ /*
+ * Only wait on writeback if we have already done a pass where
+ * we we may have triggered writeouts for lots of pages.
+ */
+ if (pass > 0) {
+ wait_on_page_writeback(page);
+ } else {
+ if (PageWriteback(page))
+ goto unlock_page;
+ }
+
+ /*
+ * Anonymous pages must have swap cache references otherwise
+ * the information contained in the page maps cannot be
+ * preserved.
+ */
+ if (PageAnon(page) && !PageSwapCache(page)) {
+ if (!add_to_swap(page, GFP_KERNEL)) {
+ rc = -ENOMEM;
+ goto unlock_page;
+ }
+ }
+
+ if (!to) {
+ rc = swap_page(page);
+ goto next;
+ }
+
+ newpage = lru_to_page(to);
+ lock_page(newpage);
+
+ /*
+ * Pages are properly locked and writeback is complete.
+ * Try to migrate the page.
+ */
+ mapping = page_mapping(page);
+ if (!mapping)
+ goto unlock_both;
+
+ if (mapping->a_ops->migratepage) {
+ rc = mapping->a_ops->migratepage(newpage, page);
+ goto unlock_both;
+ }
+
+ /*
+ * Trigger writeout if page is dirty
+ */
+ if (PageDirty(page)) {
+ switch (pageout(page, mapping)) {
+ case PAGE_KEEP:
+ case PAGE_ACTIVATE:
+ goto unlock_both;
+
+ case PAGE_SUCCESS:
+ unlock_page(newpage);
+ goto next;
+
+ case PAGE_CLEAN:
+ ; /* try to migrate the page below */
+ }
+ }
+ /*
+ * If we have no buffer or can release the buffer
+ * then do a simple migration.
+ */
+ if (!page_has_buffers(page) ||
+ try_to_release_page(page, GFP_KERNEL)) {
+ rc = migrate_page(newpage, page);
+ goto unlock_both;
+ }
+
+ /*
+ * On early passes with mapped pages simply
+ * retry. There may be a lock held for some
+ * buffers that may go away. Later
+ * swap them out.
+ */
+ if (pass > 4) {
+ unlock_page(newpage);
+ newpage = NULL;
+ rc = swap_page(page);
+ goto next;
+ }
+
+unlock_both:
+ unlock_page(newpage);
+
+unlock_page:
+ unlock_page(page);
+
+next:
+ if (rc == -EAGAIN) {
+ retry++;
+ } else if (rc) {
+ /* Permanent failure */
+ list_move(&page->lru, failed);
+ nr_failed++;
+ } else {
+ if (newpage) {
+ /* Successful migration. Return page to LRU */
+ move_to_lru(newpage);
+ }
+ list_move(&page->lru, moved);
+ }
+ }
+ if (retry && pass++ < 10)
+ goto redo;
+
+ if (!swapwrite)
+ current->flags &= ~PF_SWAPWRITE;
+
+ return nr_failed + retry;
+}
+
+/*
+ * Isolate one page from the LRU lists and put it on the
+ * indicated list with elevated refcount.
+ *
+ * Result:
+ * 0 = page not on LRU list
+ * 1 = page removed from LRU list and added to the specified list.
+ */
+int isolate_lru_page(struct page *page)
+{
+ int ret = 0;
+
+ if (PageLRU(page)) {
+ struct zone *zone = page_zone(page);
+ spin_lock_irq(&zone->lru_lock);
+ if (TestClearPageLRU(page)) {
+ ret = 1;
+ get_page(page);
+ if (PageActive(page))
+ del_page_from_active_list(zone, page);
+ else
+ del_page_from_inactive_list(zone, page);
+ }
+ spin_unlock_irq(&zone->lru_lock);
+ }
+
+ return ret;
+}
+#endif
+
/*
* zone->lru_lock is heavily contended. Some of the functions that
* shrink the lists perform better by taking out a batch of pages
goto done;
max_scan -= nr_scan;
- if (current_is_kswapd())
- mod_page_state_zone(zone, pgscan_kswapd, nr_scan);
- else
- mod_page_state_zone(zone, pgscan_direct, nr_scan);
nr_freed = shrink_list(&page_list, sc);
- if (current_is_kswapd())
- mod_page_state(kswapd_steal, nr_freed);
- mod_page_state_zone(zone, pgsteal, nr_freed);
- sc->nr_to_reclaim -= nr_freed;
- spin_lock_irq(&zone->lru_lock);
+ local_irq_disable();
+ if (current_is_kswapd()) {
+ __mod_page_state_zone(zone, pgscan_kswapd, nr_scan);
+ __mod_page_state(kswapd_steal, nr_freed);
+ } else
+ __mod_page_state_zone(zone, pgscan_direct, nr_scan);
+ __mod_page_state_zone(zone, pgsteal, nr_freed);
+
+ spin_lock(&zone->lru_lock);
/*
* Put back any unfreeable pages.
*/
if (page_mapped(page)) {
if (!reclaim_mapped ||
(total_swap_pages == 0 && PageAnon(page)) ||
- page_referenced(page, 0, sc->priority <= 0)) {
+ page_referenced(page, 0)) {
list_add(&page->lru, &l_active);
continue;
}
}
}
zone->nr_active += pgmoved;
- spin_unlock_irq(&zone->lru_lock);
- pagevec_release(&pvec);
+ spin_unlock(&zone->lru_lock);
- mod_page_state_zone(zone, pgrefill, pgscanned);
- mod_page_state(pgdeactivate, pgdeactivate);
+ __mod_page_state_zone(zone, pgrefill, pgscanned);
+ __mod_page_state(pgdeactivate, pgdeactivate);
+ local_irq_enable();
+
+ pagevec_release(&pvec);
}
/*
else
nr_inactive = 0;
- sc->nr_to_reclaim = sc->swap_cluster_max;
-
while (nr_active || nr_inactive) {
if (nr_active) {
sc->nr_to_scan = min(nr_active,
(unsigned long)sc->swap_cluster_max);
nr_inactive -= sc->nr_to_scan;
shrink_cache(zone, sc);
- if (sc->nr_to_reclaim <= 0)
- break;
}
}
for (i = 0; zones[i] != NULL; i++) {
struct zone *zone = zones[i];
- if (zone->present_pages == 0)
+ if (!populated_zone(zone))
continue;
if (!cpuset_zone_allowed(zone, __GFP_HARDWALL))
int i;
sc.gfp_mask = gfp_mask;
- sc.may_writepage = 0;
+ sc.may_writepage = !laptop_mode;
sc.may_swap = 1;
inc_page_state(allocstall);
sc.nr_reclaimed = 0;
sc.priority = priority;
sc.swap_cluster_max = SWAP_CLUSTER_MAX;
+ if (!priority)
+ disable_swap_token();
shrink_caches(zones, &sc);
shrink_slab(sc.nr_scanned, gfp_mask, lru_pages);
if (reclaim_state) {
total_scanned = 0;
total_reclaimed = 0;
sc.gfp_mask = GFP_KERNEL;
- sc.may_writepage = 0;
+ sc.may_writepage = !laptop_mode;
sc.may_swap = 1;
sc.nr_mapped = read_page_state(nr_mapped);
int end_zone = 0; /* Inclusive. 0 = ZONE_DMA */
unsigned long lru_pages = 0;
+ /* The swap token gets in the way of swapout... */
+ if (!priority)
+ disable_swap_token();
+
all_zones_ok = 1;
if (nr_pages == 0) {
for (i = pgdat->nr_zones - 1; i >= 0; i--) {
struct zone *zone = pgdat->node_zones + i;
- if (zone->present_pages == 0)
+ if (!populated_zone(zone))
continue;
if (zone->all_unreclaimable &&
continue;
if (!zone_watermark_ok(zone, order,
- zone->pages_high, 0, 0, 0)) {
+ zone->pages_high, 0, 0)) {
end_zone = i;
goto scan;
}
struct zone *zone = pgdat->node_zones + i;
int nr_slab;
- if (zone->present_pages == 0)
+ if (!populated_zone(zone))
continue;
if (zone->all_unreclaimable && priority != DEF_PRIORITY)
if (nr_pages == 0) { /* Not software suspend */
if (!zone_watermark_ok(zone, order,
- zone->pages_high, end_zone, 0, 0))
+ zone->pages_high, end_zone, 0))
all_zones_ok = 0;
}
zone->temp_priority = priority;
* us from recursively trying to free more memory as we're
* trying to free the first piece of memory in the first place).
*/
- tsk->flags |= PF_MEMALLOC|PF_KSWAPD;
+ tsk->flags |= PF_MEMALLOC | PF_SWAPWRITE | PF_KSWAPD;
order = 0;
for ( ; ; ) {
{
pg_data_t *pgdat;
- if (zone->present_pages == 0)
+ if (!populated_zone(zone))
return;
pgdat = zone->zone_pgdat;
- if (zone_watermark_ok(zone, order, zone->pages_low, 0, 0, 0))
+ if (zone_watermark_ok(zone, order, zone->pages_low, 0, 0))
return;
if (pgdat->kswapd_max_order < order)
pgdat->kswapd_max_order = order;
module_init(kswapd_init)
+#ifdef CONFIG_NUMA
+/*
+ * Zone reclaim mode
+ *
+ * If non-zero call zone_reclaim when the number of free pages falls below
+ * the watermarks.
+ *
+ * In the future we may add flags to the mode. However, the page allocator
+ * should only have to check that zone_reclaim_mode != 0 before calling
+ * zone_reclaim().
+ */
+int zone_reclaim_mode __read_mostly;
+
+#define RECLAIM_OFF 0
+#define RECLAIM_ZONE (1<<0) /* Run shrink_cache on the zone */
+#define RECLAIM_WRITE (1<<1) /* Writeout pages during reclaim */
+#define RECLAIM_SWAP (1<<2) /* Swap pages out during reclaim */
+#define RECLAIM_SLAB (1<<3) /* Do a global slab shrink if the zone is out of memory */
+
+/*
+ * Mininum time between zone reclaim scans
+ */
+int zone_reclaim_interval __read_mostly = 30*HZ;
+
+/*
+ * Priority for ZONE_RECLAIM. This determines the fraction of pages
+ * of a node considered for each zone_reclaim. 4 scans 1/16th of
+ * a zone.
+ */
+#define ZONE_RECLAIM_PRIORITY 4
/*
* Try to free up some pages from this zone through reclaim.
*/
int zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
{
+ int nr_pages;
+ struct task_struct *p = current;
+ struct reclaim_state reclaim_state;
struct scan_control sc;
- int nr_pages = 1 << order;
- int total_reclaimed = 0;
+ cpumask_t mask;
+ int node_id;
- /* The reclaim may sleep, so don't do it if sleep isn't allowed */
- if (!(gfp_mask & __GFP_WAIT))
- return 0;
- if (zone->all_unreclaimable)
+ if (time_before(jiffies,
+ zone->last_unsuccessful_zone_reclaim + zone_reclaim_interval))
+ return 0;
+
+ if (!(gfp_mask & __GFP_WAIT) ||
+ zone->all_unreclaimable ||
+ atomic_read(&zone->reclaim_in_progress) > 0)
+ return 0;
+
+ node_id = zone->zone_pgdat->node_id;
+ mask = node_to_cpumask(node_id);
+ if (!cpus_empty(mask) && node_id != numa_node_id())
return 0;
- sc.gfp_mask = gfp_mask;
- sc.may_writepage = 0;
- sc.may_swap = 0;
- sc.nr_mapped = read_page_state(nr_mapped);
+ sc.may_writepage = !!(zone_reclaim_mode & RECLAIM_WRITE);
+ sc.may_swap = !!(zone_reclaim_mode & RECLAIM_SWAP);
sc.nr_scanned = 0;
sc.nr_reclaimed = 0;
- /* scan at the highest priority */
- sc.priority = 0;
+ sc.priority = ZONE_RECLAIM_PRIORITY + 1;
+ sc.nr_mapped = read_page_state(nr_mapped);
+ sc.gfp_mask = gfp_mask;
+
+ disable_swap_token();
+ nr_pages = 1 << order;
if (nr_pages > SWAP_CLUSTER_MAX)
sc.swap_cluster_max = nr_pages;
else
sc.swap_cluster_max = SWAP_CLUSTER_MAX;
- /* Don't reclaim the zone if there are other reclaimers active */
- if (atomic_read(&zone->reclaim_in_progress) > 0)
- goto out;
-
- shrink_zone(zone, &sc);
- total_reclaimed = sc.nr_reclaimed;
-
- out:
- return total_reclaimed;
-}
-
-asmlinkage long sys_set_zone_reclaim(unsigned int node, unsigned int zone,
- unsigned int state)
-{
- struct zone *z;
- int i;
-
- if (!capable(CAP_SYS_ADMIN))
- return -EACCES;
+ cond_resched();
+ p->flags |= PF_MEMALLOC;
+ reclaim_state.reclaimed_slab = 0;
+ p->reclaim_state = &reclaim_state;
- if (node >= MAX_NUMNODES || !node_online(node))
- return -EINVAL;
+ /*
+ * Free memory by calling shrink zone with increasing priorities
+ * until we have enough memory freed.
+ */
+ do {
+ sc.priority--;
+ shrink_zone(zone, &sc);
- /* This will break if we ever add more zones */
- if (!(zone & (1<<ZONE_DMA|1<<ZONE_NORMAL|1<<ZONE_HIGHMEM)))
- return -EINVAL;
+ } while (sc.nr_reclaimed < nr_pages && sc.priority > 0);
- for (i = 0; i < MAX_NR_ZONES; i++) {
- if (!(zone & 1<<i))
- continue;
+ if (sc.nr_reclaimed < nr_pages && (zone_reclaim_mode & RECLAIM_SLAB)) {
+ /*
+ * shrink_slab does not currently allow us to determine
+ * how many pages were freed in the zone. So we just
+ * shake the slab and then go offnode for a single allocation.
+ *
+ * shrink_slab will free memory on all zones and may take
+ * a long time.
+ */
+ shrink_slab(sc.nr_scanned, gfp_mask, order);
+ sc.nr_reclaimed = 1; /* Avoid getting the off node timeout */
+ }
- z = &NODE_DATA(node)->node_zones[i];
+ p->reclaim_state = NULL;
+ current->flags &= ~PF_MEMALLOC;
- if (state)
- z->reclaim_pages = 1;
- else
- z->reclaim_pages = 0;
- }
+ if (sc.nr_reclaimed == 0)
+ zone->last_unsuccessful_zone_reclaim = jiffies;
- return 0;
+ return sc.nr_reclaimed >= nr_pages;
}
+#endif
+
git.openpandora.org / pandora-kernel.git / blobdiff