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-rw-r--r--mm/vmscan.c265
1 files changed, 178 insertions, 87 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c
index c391c320dba..b8a6fdc2131 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -51,6 +51,12 @@
#define CREATE_TRACE_POINTS
#include <trace/events/vmscan.h>
+enum lumpy_mode {
+ LUMPY_MODE_NONE,
+ LUMPY_MODE_ASYNC,
+ LUMPY_MODE_SYNC,
+};
+
struct scan_control {
/* Incremented by the number of inactive pages that were scanned */
unsigned long nr_scanned;
@@ -79,10 +85,10 @@ struct scan_control {
int order;
/*
- * Intend to reclaim enough contenious memory rather than to reclaim
- * enough amount memory. I.e, it's the mode for high order allocation.
+ * Intend to reclaim enough continuous memory rather than reclaim
+ * enough amount of memory. i.e, mode for high order allocation.
*/
- bool lumpy_reclaim_mode;
+ enum lumpy_mode lumpy_reclaim_mode;
/* Which cgroup do we reclaim from */
struct mem_cgroup *mem_cgroup;
@@ -265,6 +271,36 @@ unsigned long shrink_slab(unsigned long scanned, gfp_t gfp_mask,
return ret;
}
+static void set_lumpy_reclaim_mode(int priority, struct scan_control *sc,
+ bool sync)
+{
+ enum lumpy_mode mode = sync ? LUMPY_MODE_SYNC : LUMPY_MODE_ASYNC;
+
+ /*
+ * Some reclaim have alredy been failed. No worth to try synchronous
+ * lumpy reclaim.
+ */
+ if (sync && sc->lumpy_reclaim_mode == LUMPY_MODE_NONE)
+ return;
+
+ /*
+ * If we need a large contiguous chunk of memory, or have
+ * trouble getting a small set of contiguous pages, we
+ * will reclaim both active and inactive pages.
+ */
+ if (sc->order > PAGE_ALLOC_COSTLY_ORDER)
+ sc->lumpy_reclaim_mode = mode;
+ else if (sc->order && priority < DEF_PRIORITY - 2)
+ sc->lumpy_reclaim_mode = mode;
+ else
+ sc->lumpy_reclaim_mode = LUMPY_MODE_NONE;
+}
+
+static void disable_lumpy_reclaim_mode(struct scan_control *sc)
+{
+ sc->lumpy_reclaim_mode = LUMPY_MODE_NONE;
+}
+
static inline int is_page_cache_freeable(struct page *page)
{
/*
@@ -275,7 +311,8 @@ static inline int is_page_cache_freeable(struct page *page)
return page_count(page) - page_has_private(page) == 2;
}
-static int may_write_to_queue(struct backing_dev_info *bdi)
+static int may_write_to_queue(struct backing_dev_info *bdi,
+ struct scan_control *sc)
{
if (current->flags & PF_SWAPWRITE)
return 1;
@@ -283,6 +320,10 @@ static int may_write_to_queue(struct backing_dev_info *bdi)
return 1;
if (bdi == current->backing_dev_info)
return 1;
+
+ /* lumpy reclaim for hugepage often need a lot of write */
+ if (sc->order > PAGE_ALLOC_COSTLY_ORDER)
+ return 1;
return 0;
}
@@ -307,12 +348,6 @@ static void handle_write_error(struct address_space *mapping,
unlock_page(page);
}
-/* Request for sync pageout. */
-enum pageout_io {
- PAGEOUT_IO_ASYNC,
- PAGEOUT_IO_SYNC,
-};
-
/* possible outcome of pageout() */
typedef enum {
/* failed to write page out, page is locked */
@@ -330,7 +365,7 @@ typedef enum {
* Calls ->writepage().
*/
static pageout_t pageout(struct page *page, struct address_space *mapping,
- enum pageout_io sync_writeback)
+ struct scan_control *sc)
{
/*
* If the page is dirty, only perform writeback if that write
@@ -366,7 +401,7 @@ static pageout_t pageout(struct page *page, struct address_space *mapping,
}
if (mapping->a_ops->writepage == NULL)
return PAGE_ACTIVATE;
- if (!may_write_to_queue(mapping->backing_dev_info))
+ if (!may_write_to_queue(mapping->backing_dev_info, sc))
return PAGE_KEEP;
if (clear_page_dirty_for_io(page)) {
@@ -376,7 +411,6 @@ static pageout_t pageout(struct page *page, struct address_space *mapping,
.nr_to_write = SWAP_CLUSTER_MAX,
.range_start = 0,
.range_end = LLONG_MAX,
- .nonblocking = 1,
.for_reclaim = 1,
};
@@ -394,7 +428,8 @@ static pageout_t pageout(struct page *page, struct address_space *mapping,
* direct reclaiming a large contiguous area and the
* first attempt to free a range of pages fails.
*/
- if (PageWriteback(page) && sync_writeback == PAGEOUT_IO_SYNC)
+ if (PageWriteback(page) &&
+ sc->lumpy_reclaim_mode == LUMPY_MODE_SYNC)
wait_on_page_writeback(page);
if (!PageWriteback(page)) {
@@ -402,7 +437,7 @@ static pageout_t pageout(struct page *page, struct address_space *mapping,
ClearPageReclaim(page);
}
trace_mm_vmscan_writepage(page,
- trace_reclaim_flags(page, sync_writeback));
+ trace_reclaim_flags(page, sc->lumpy_reclaim_mode));
inc_zone_page_state(page, NR_VMSCAN_WRITE);
return PAGE_SUCCESS;
}
@@ -580,7 +615,7 @@ static enum page_references page_check_references(struct page *page,
referenced_page = TestClearPageReferenced(page);
/* Lumpy reclaim - ignore references */
- if (sc->lumpy_reclaim_mode)
+ if (sc->lumpy_reclaim_mode != LUMPY_MODE_NONE)
return PAGEREF_RECLAIM;
/*
@@ -616,7 +651,7 @@ static enum page_references page_check_references(struct page *page,
}
/* Reclaim if clean, defer dirty pages to writeback */
- if (referenced_page)
+ if (referenced_page && !PageSwapBacked(page))
return PAGEREF_RECLAIM_CLEAN;
return PAGEREF_RECLAIM;
@@ -644,12 +679,14 @@ static noinline_for_stack void free_page_list(struct list_head *free_pages)
* shrink_page_list() returns the number of reclaimed pages
*/
static unsigned long shrink_page_list(struct list_head *page_list,
- struct scan_control *sc,
- enum pageout_io sync_writeback)
+ struct zone *zone,
+ struct scan_control *sc)
{
LIST_HEAD(ret_pages);
LIST_HEAD(free_pages);
int pgactivate = 0;
+ unsigned long nr_dirty = 0;
+ unsigned long nr_congested = 0;
unsigned long nr_reclaimed = 0;
cond_resched();
@@ -669,6 +706,7 @@ static unsigned long shrink_page_list(struct list_head *page_list,
goto keep;
VM_BUG_ON(PageActive(page));
+ VM_BUG_ON(page_zone(page) != zone);
sc->nr_scanned++;
@@ -694,10 +732,13 @@ static unsigned long shrink_page_list(struct list_head *page_list,
* for any page for which writeback has already
* started.
*/
- if (sync_writeback == PAGEOUT_IO_SYNC && may_enter_fs)
+ if (sc->lumpy_reclaim_mode == LUMPY_MODE_SYNC &&
+ may_enter_fs)
wait_on_page_writeback(page);
- else
- goto keep_locked;
+ else {
+ unlock_page(page);
+ goto keep_lumpy;
+ }
}
references = page_check_references(page, sc);
@@ -743,6 +784,8 @@ static unsigned long shrink_page_list(struct list_head *page_list,
}
if (PageDirty(page)) {
+ nr_dirty++;
+
if (references == PAGEREF_RECLAIM_CLEAN)
goto keep_locked;
if (!may_enter_fs)
@@ -751,14 +794,18 @@ static unsigned long shrink_page_list(struct list_head *page_list,
goto keep_locked;
/* Page is dirty, try to write it out here */
- switch (pageout(page, mapping, sync_writeback)) {
+ switch (pageout(page, mapping, sc)) {
case PAGE_KEEP:
+ nr_congested++;
goto keep_locked;
case PAGE_ACTIVATE:
goto activate_locked;
case PAGE_SUCCESS:
- if (PageWriteback(page) || PageDirty(page))
+ if (PageWriteback(page))
+ goto keep_lumpy;
+ if (PageDirty(page))
goto keep;
+
/*
* A synchronous write - probably a ramdisk. Go
* ahead and try to reclaim the page.
@@ -841,6 +888,7 @@ cull_mlocked:
try_to_free_swap(page);
unlock_page(page);
putback_lru_page(page);
+ disable_lumpy_reclaim_mode(sc);
continue;
activate_locked:
@@ -853,10 +901,21 @@ activate_locked:
keep_locked:
unlock_page(page);
keep:
+ disable_lumpy_reclaim_mode(sc);
+keep_lumpy:
list_add(&page->lru, &ret_pages);
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_congested)
+ zone_set_flag(zone, ZONE_CONGESTED);
+
free_page_list(&free_pages);
list_splice(&ret_pages, page_list);
@@ -1006,7 +1065,7 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
/* Check that we have not crossed a zone boundary. */
if (unlikely(page_zone_id(cursor_page) != zone_id))
- continue;
+ break;
/*
* If we don't have enough swap space, reclaiming of
@@ -1014,8 +1073,8 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
* pointless.
*/
if (nr_swap_pages <= 0 && PageAnon(cursor_page) &&
- !PageSwapCache(cursor_page))
- continue;
+ !PageSwapCache(cursor_page))
+ break;
if (__isolate_lru_page(cursor_page, mode, file) == 0) {
list_move(&cursor_page->lru, dst);
@@ -1026,11 +1085,16 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
nr_lumpy_dirty++;
scan++;
} else {
- if (mode == ISOLATE_BOTH &&
- page_count(cursor_page))
- nr_lumpy_failed++;
+ /* the page is freed already. */
+ if (!page_count(cursor_page))
+ continue;
+ break;
}
}
+
+ /* If we break out of the loop above, lumpy reclaim failed */
+ if (pfn < end_pfn)
+ nr_lumpy_failed++;
}
*scanned = scan;
@@ -1253,7 +1317,7 @@ static inline bool should_reclaim_stall(unsigned long nr_taken,
return false;
/* Only stall on lumpy reclaim */
- if (!sc->lumpy_reclaim_mode)
+ if (sc->lumpy_reclaim_mode == LUMPY_MODE_NONE)
return false;
/* If we have relaimed everything on the isolated list, no stall */
@@ -1286,7 +1350,6 @@ shrink_inactive_list(unsigned long nr_to_scan, struct zone *zone,
unsigned long nr_scanned;
unsigned long nr_reclaimed = 0;
unsigned long nr_taken;
- unsigned long nr_active;
unsigned long nr_anon;
unsigned long nr_file;
@@ -1298,15 +1361,15 @@ shrink_inactive_list(unsigned long nr_to_scan, struct zone *zone,
return SWAP_CLUSTER_MAX;
}
-
+ set_lumpy_reclaim_mode(priority, sc, false);
lru_add_drain();
spin_lock_irq(&zone->lru_lock);
if (scanning_global_lru(sc)) {
nr_taken = isolate_pages_global(nr_to_scan,
&page_list, &nr_scanned, sc->order,
- sc->lumpy_reclaim_mode ?
- ISOLATE_BOTH : ISOLATE_INACTIVE,
+ sc->lumpy_reclaim_mode == LUMPY_MODE_NONE ?
+ ISOLATE_INACTIVE : ISOLATE_BOTH,
zone, 0, file);
zone->pages_scanned += nr_scanned;
if (current_is_kswapd())
@@ -1318,8 +1381,8 @@ shrink_inactive_list(unsigned long nr_to_scan, struct zone *zone,
} else {
nr_taken = mem_cgroup_isolate_pages(nr_to_scan,
&page_list, &nr_scanned, sc->order,
- sc->lumpy_reclaim_mode ?
- ISOLATE_BOTH : ISOLATE_INACTIVE,
+ sc->lumpy_reclaim_mode == LUMPY_MODE_NONE ?
+ ISOLATE_INACTIVE : ISOLATE_BOTH,
zone, sc->mem_cgroup,
0, file);
/*
@@ -1337,20 +1400,12 @@ shrink_inactive_list(unsigned long nr_to_scan, struct zone *zone,
spin_unlock_irq(&zone->lru_lock);
- nr_reclaimed = shrink_page_list(&page_list, sc, PAGEOUT_IO_ASYNC);
+ nr_reclaimed = shrink_page_list(&page_list, zone, sc);
/* Check if we should syncronously wait for writeback */
if (should_reclaim_stall(nr_taken, nr_reclaimed, priority, sc)) {
- congestion_wait(BLK_RW_ASYNC, HZ/10);
-
- /*
- * The attempt at page out may have made some
- * of the pages active, mark them inactive again.
- */
- nr_active = clear_active_flags(&page_list, NULL);
- count_vm_events(PGDEACTIVATE, nr_active);
-
- nr_reclaimed += shrink_page_list(&page_list, sc, PAGEOUT_IO_SYNC);
+ set_lumpy_reclaim_mode(priority, sc, true);
+ nr_reclaimed += shrink_page_list(&page_list, zone, sc);
}
local_irq_disable();
@@ -1359,6 +1414,12 @@ shrink_inactive_list(unsigned long nr_to_scan, struct zone *zone,
__count_zone_vm_events(PGSTEAL, zone, nr_reclaimed);
putback_lru_pages(zone, sc, nr_anon, nr_file, &page_list);
+
+ trace_mm_vmscan_lru_shrink_inactive(zone->zone_pgdat->node_id,
+ zone_idx(zone),
+ nr_scanned, nr_reclaimed,
+ priority,
+ trace_shrink_flags(file, sc->lumpy_reclaim_mode));
return nr_reclaimed;
}
@@ -1506,6 +1567,7 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
spin_unlock_irq(&zone->lru_lock);
}
+#ifdef CONFIG_SWAP
static int inactive_anon_is_low_global(struct zone *zone)
{
unsigned long active, inactive;
@@ -1531,12 +1593,26 @@ static int inactive_anon_is_low(struct zone *zone, struct scan_control *sc)
{
int low;
+ /*
+ * If we don't have swap space, anonymous page deactivation
+ * is pointless.
+ */
+ if (!total_swap_pages)
+ return 0;
+
if (scanning_global_lru(sc))
low = inactive_anon_is_low_global(zone);
else
low = mem_cgroup_inactive_anon_is_low(sc->mem_cgroup);
return low;
}
+#else
+static inline int inactive_anon_is_low(struct zone *zone,
+ struct scan_control *sc)
+{
+ return 0;
+}
+#endif
static int inactive_file_is_low_global(struct zone *zone)
{
@@ -1721,21 +1797,6 @@ out:
}
}
-static void set_lumpy_reclaim_mode(int priority, struct scan_control *sc)
-{
- /*
- * If we need a large contiguous chunk of memory, or have
- * trouble getting a small set of contiguous pages, we
- * will reclaim both active and inactive pages.
- */
- if (sc->order > PAGE_ALLOC_COSTLY_ORDER)
- sc->lumpy_reclaim_mode = 1;
- else if (sc->order && priority < DEF_PRIORITY - 2)
- sc->lumpy_reclaim_mode = 1;
- else
- sc->lumpy_reclaim_mode = 0;
-}
-
/*
* This is a basic per-zone page freer. Used by both kswapd and direct reclaim.
*/
@@ -1750,8 +1811,6 @@ static void shrink_zone(int priority, struct zone *zone,
get_scan_count(zone, sc, nr, priority);
- set_lumpy_reclaim_mode(priority, sc);
-
while (nr[LRU_INACTIVE_ANON] || nr[LRU_ACTIVE_FILE] ||
nr[LRU_INACTIVE_FILE]) {
for_each_evictable_lru(l) {
@@ -1782,7 +1841,7 @@ static void shrink_zone(int priority, struct zone *zone,
* Even if we did not try to evict anon pages at all, we want to
* rebalance the anon lru active/inactive ratio.
*/
- if (inactive_anon_is_low(zone, sc) && nr_swap_pages > 0)
+ if (inactive_anon_is_low(zone, sc))
shrink_active_list(SWAP_CLUSTER_MAX, zone, sc, priority, 0);
throttle_vm_writeout(sc->gfp_mask);
@@ -1804,12 +1863,11 @@ static void shrink_zone(int priority, struct zone *zone,
* If a zone is deemed to be full of pinned pages then just give it a light
* scan then give up on it.
*/
-static bool shrink_zones(int priority, struct zonelist *zonelist,
+static void shrink_zones(int priority, struct zonelist *zonelist,
struct scan_control *sc)
{
struct zoneref *z;
struct zone *zone;
- bool all_unreclaimable = true;
for_each_zone_zonelist_nodemask(zone, z, zonelist,
gfp_zone(sc->gfp_mask), sc->nodemask) {
@@ -1827,8 +1885,38 @@ static bool shrink_zones(int priority, struct zonelist *zonelist,
}
shrink_zone(priority, zone, sc);
- all_unreclaimable = false;
}
+}
+
+static bool zone_reclaimable(struct zone *zone)
+{
+ return zone->pages_scanned < zone_reclaimable_pages(zone) * 6;
+}
+
+/*
+ * As hibernation is going on, kswapd is freezed so that it can't mark
+ * the zone into all_unreclaimable. It can't handle OOM during hibernation.
+ * So let's check zone's unreclaimable in direct reclaim as well as kswapd.
+ */
+static bool all_unreclaimable(struct zonelist *zonelist,
+ struct scan_control *sc)
+{
+ struct zoneref *z;
+ struct zone *zone;
+ bool all_unreclaimable = true;
+
+ for_each_zone_zonelist_nodemask(zone, z, zonelist,
+ gfp_zone(sc->gfp_mask), sc->nodemask) {
+ if (!populated_zone(zone))
+ continue;
+ if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL))
+ continue;
+ if (zone_reclaimable(zone)) {
+ all_unreclaimable = false;
+ break;
+ }
+ }
+
return all_unreclaimable;
}
@@ -1852,7 +1940,6 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
struct scan_control *sc)
{
int priority;
- bool all_unreclaimable;
unsigned long total_scanned = 0;
struct reclaim_state *reclaim_state = current->reclaim_state;
struct zoneref *z;
@@ -1869,7 +1956,7 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
sc->nr_scanned = 0;
if (!priority)
disable_swap_token();
- all_unreclaimable = shrink_zones(priority, zonelist, sc);
+ shrink_zones(priority, zonelist, sc);
/*
* Don't shrink slabs when reclaiming memory from
* over limit cgroups
@@ -1909,21 +1996,16 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
/* Take a nap, wait for some writeback to complete */
if (!sc->hibernation_mode && sc->nr_scanned &&
- priority < DEF_PRIORITY - 2)
- congestion_wait(BLK_RW_ASYNC, HZ/10);
+ priority < DEF_PRIORITY - 2) {
+ struct zone *preferred_zone;
+
+ first_zones_zonelist(zonelist, gfp_zone(sc->gfp_mask),
+ NULL, &preferred_zone);
+ wait_iff_congested(preferred_zone, BLK_RW_ASYNC, HZ/10);
+ }
}
out:
- /*
- * Now that we've scanned all the zones at this priority level, note
- * that level within the zone so that the next thread which performs
- * scanning of this zone will immediately start out at this priority
- * level. This affects only the decision whether or not to bring
- * mapped pages onto the inactive list.
- */
- if (priority < 0)
- priority = 0;
-
delayacct_freepages_end();
put_mems_allowed();
@@ -1931,7 +2013,7 @@ out:
return sc->nr_reclaimed;
/* top priority shrink_zones still had more to do? don't OOM, then */
- if (scanning_global_lru(sc) && !all_unreclaimable)
+ if (scanning_global_lru(sc) && !all_unreclaimable(zonelist, sc))
return 1;
return 0;
@@ -2197,8 +2279,7 @@ loop_again:
total_scanned += sc.nr_scanned;
if (zone->all_unreclaimable)
continue;
- if (nr_slab == 0 &&
- zone->pages_scanned >= (zone_reclaimable_pages(zone) * 6))
+ if (nr_slab == 0 && !zone_reclaimable(zone))
zone->all_unreclaimable = 1;
/*
* If we've done a decent amount of scanning and
@@ -2220,6 +2301,15 @@ loop_again:
if (!zone_watermark_ok(zone, order,
min_wmark_pages(zone), end_zone, 0))
has_under_min_watermark_zone = 1;
+ } else {
+ /*
+ * 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,
+ * spectulatively avoid congestion waits
+ */
+ zone_clear_flag(zone, ZONE_CONGESTED);
}
}
@@ -2960,6 +3050,7 @@ int scan_unevictable_handler(struct ctl_table *table, int write,
return 0;
}
+#ifdef CONFIG_NUMA
/*
* per node 'scan_unevictable_pages' attribute. On demand re-scan of
* a specified node's per zone unevictable lists for evictable pages.
@@ -3006,4 +3097,4 @@ void scan_unevictable_unregister_node(struct node *node)
{
sysdev_remove_file(&node->sysdev, &attr_scan_unevictable_pages);
}
-
+#endif
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-11-11 04:43:09 +0000