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-rw-r--r--mm/vmscan.c156
1 files changed, 95 insertions, 61 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c
index c26986c85ce..3ff3311447f 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -13,7 +13,7 @@
#include <linux/mm.h>
#include <linux/module.h>
-#include <linux/slab.h>
+#include <linux/gfp.h>
#include <linux/kernel_stat.h>
#include <linux/swap.h>
#include <linux/pagemap.h>
@@ -262,27 +262,6 @@ unsigned long shrink_slab(unsigned long scanned, gfp_t gfp_mask,
return ret;
}
-/* Called without lock on whether page is mapped, so answer is unstable */
-static inline int page_mapping_inuse(struct page *page)
-{
- struct address_space *mapping;
-
- /* Page is in somebody's page tables. */
- if (page_mapped(page))
- return 1;
-
- /* Be more reluctant to reclaim swapcache than pagecache */
- if (PageSwapCache(page))
- return 1;
-
- mapping = page_mapping(page);
- if (!mapping)
- return 0;
-
- /* File is mmap'd by somebody? */
- return mapping_mapped(mapping);
-}
-
static inline int is_page_cache_freeable(struct page *page)
{
/*
@@ -579,6 +558,65 @@ redo:
put_page(page); /* drop ref from isolate */
}
+enum page_references {
+ PAGEREF_RECLAIM,
+ PAGEREF_RECLAIM_CLEAN,
+ PAGEREF_KEEP,
+ PAGEREF_ACTIVATE,
+};
+
+static enum page_references page_check_references(struct page *page,
+ struct scan_control *sc)
+{
+ int referenced_ptes, referenced_page;
+ unsigned long vm_flags;
+
+ referenced_ptes = page_referenced(page, 1, sc->mem_cgroup, &vm_flags);
+ referenced_page = TestClearPageReferenced(page);
+
+ /* Lumpy reclaim - ignore references */
+ if (sc->order > PAGE_ALLOC_COSTLY_ORDER)
+ return PAGEREF_RECLAIM;
+
+ /*
+ * Mlock lost the isolation race with us. Let try_to_unmap()
+ * move the page to the unevictable list.
+ */
+ if (vm_flags & VM_LOCKED)
+ return PAGEREF_RECLAIM;
+
+ if (referenced_ptes) {
+ if (PageAnon(page))
+ return PAGEREF_ACTIVATE;
+ /*
+ * All mapped pages start out with page table
+ * references from the instantiating fault, so we need
+ * to look twice if a mapped file page is used more
+ * than once.
+ *
+ * Mark it and spare it for another trip around the
+ * inactive list. Another page table reference will
+ * lead to its activation.
+ *
+ * Note: the mark is set for activated pages as well
+ * so that recently deactivated but used pages are
+ * quickly recovered.
+ */
+ SetPageReferenced(page);
+
+ if (referenced_page)
+ return PAGEREF_ACTIVATE;
+
+ return PAGEREF_KEEP;
+ }
+
+ /* Reclaim if clean, defer dirty pages to writeback */
+ if (referenced_page)
+ return PAGEREF_RECLAIM_CLEAN;
+
+ return PAGEREF_RECLAIM;
+}
+
/*
* shrink_page_list() returns the number of reclaimed pages
*/
@@ -590,16 +628,15 @@ static unsigned long shrink_page_list(struct list_head *page_list,
struct pagevec freed_pvec;
int pgactivate = 0;
unsigned long nr_reclaimed = 0;
- unsigned long vm_flags;
cond_resched();
pagevec_init(&freed_pvec, 1);
while (!list_empty(page_list)) {
+ enum page_references references;
struct address_space *mapping;
struct page *page;
int may_enter_fs;
- int referenced;
cond_resched();
@@ -641,17 +678,16 @@ static unsigned long shrink_page_list(struct list_head *page_list,
goto keep_locked;
}
- referenced = page_referenced(page, 1,
- sc->mem_cgroup, &vm_flags);
- /*
- * In active use or really unfreeable? Activate it.
- * If page which have PG_mlocked lost isoltation race,
- * try_to_unmap moves it to unevictable list
- */
- if (sc->order <= PAGE_ALLOC_COSTLY_ORDER &&
- referenced && page_mapping_inuse(page)
- && !(vm_flags & VM_LOCKED))
+ references = page_check_references(page, sc);
+ switch (references) {
+ case PAGEREF_ACTIVATE:
goto activate_locked;
+ case PAGEREF_KEEP:
+ goto keep_locked;
+ case PAGEREF_RECLAIM:
+ case PAGEREF_RECLAIM_CLEAN:
+ ; /* try to reclaim the page below */
+ }
/*
* Anonymous process memory has backing store?
@@ -685,7 +721,7 @@ static unsigned long shrink_page_list(struct list_head *page_list,
}
if (PageDirty(page)) {
- if (sc->order <= PAGE_ALLOC_COSTLY_ORDER && referenced)
+ if (references == PAGEREF_RECLAIM_CLEAN)
goto keep_locked;
if (!may_enter_fs)
goto keep_locked;
@@ -1350,9 +1386,7 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
continue;
}
- /* page_referenced clears PageReferenced */
- if (page_mapping_inuse(page) &&
- page_referenced(page, 0, sc->mem_cgroup, &vm_flags)) {
+ if (page_referenced(page, 0, sc->mem_cgroup, &vm_flags)) {
nr_rotated++;
/*
* Identify referenced, file-backed active pages and
@@ -1694,8 +1728,7 @@ static void shrink_zones(int priority, struct zonelist *zonelist,
continue;
note_zone_scanning_priority(zone, priority);
- if (zone_is_all_unreclaimable(zone) &&
- priority != DEF_PRIORITY)
+ if (zone->all_unreclaimable && priority != DEF_PRIORITY)
continue; /* Let kswapd poll it */
sc->all_unreclaimable = 0;
} else {
@@ -1922,7 +1955,7 @@ static int sleeping_prematurely(pg_data_t *pgdat, int order, long remaining)
if (!populated_zone(zone))
continue;
- if (zone_is_all_unreclaimable(zone))
+ if (zone->all_unreclaimable)
continue;
if (!zone_watermark_ok(zone, order, high_wmark_pages(zone),
@@ -2012,8 +2045,7 @@ loop_again:
if (!populated_zone(zone))
continue;
- if (zone_is_all_unreclaimable(zone) &&
- priority != DEF_PRIORITY)
+ if (zone->all_unreclaimable && priority != DEF_PRIORITY)
continue;
/*
@@ -2056,13 +2088,9 @@ loop_again:
if (!populated_zone(zone))
continue;
- if (zone_is_all_unreclaimable(zone) &&
- priority != DEF_PRIORITY)
+ if (zone->all_unreclaimable && priority != DEF_PRIORITY)
continue;
- if (!zone_watermark_ok(zone, order,
- high_wmark_pages(zone), end_zone, 0))
- all_zones_ok = 0;
temp_priority[i] = priority;
sc.nr_scanned = 0;
note_zone_scanning_priority(zone, priority);
@@ -2087,12 +2115,11 @@ loop_again:
lru_pages);
sc.nr_reclaimed += reclaim_state->reclaimed_slab;
total_scanned += sc.nr_scanned;
- if (zone_is_all_unreclaimable(zone))
+ if (zone->all_unreclaimable)
continue;
- if (nr_slab == 0 && zone->pages_scanned >=
- (zone_reclaimable_pages(zone) * 6))
- zone_set_flag(zone,
- ZONE_ALL_UNRECLAIMABLE);
+ if (nr_slab == 0 &&
+ zone->pages_scanned >= (zone_reclaimable_pages(zone) * 6))
+ zone->all_unreclaimable = 1;
/*
* If we've done a decent amount of scanning and
* the reclaim ratio is low, start doing writepage
@@ -2102,13 +2129,18 @@ loop_again:
total_scanned > sc.nr_reclaimed + sc.nr_reclaimed / 2)
sc.may_writepage = 1;
- /*
- * We are still under min water mark. it mean we have
- * GFP_ATOMIC allocation failure risk. Hurry up!
- */
- if (!zone_watermark_ok(zone, order, min_wmark_pages(zone),
- end_zone, 0))
- has_under_min_watermark_zone = 1;
+ if (!zone_watermark_ok(zone, order,
+ high_wmark_pages(zone), end_zone, 0)) {
+ all_zones_ok = 0;
+ /*
+ * We are still under min water mark. This
+ * means that we have a GFP_ATOMIC allocation
+ * failure risk. Hurry up!
+ */
+ if (!zone_watermark_ok(zone, order,
+ min_wmark_pages(zone), end_zone, 0))
+ has_under_min_watermark_zone = 1;
+ }
}
if (all_zones_ok)
@@ -2550,6 +2582,7 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
* and RECLAIM_SWAP.
*/
p->flags |= PF_MEMALLOC | PF_SWAPWRITE;
+ lockdep_set_current_reclaim_state(gfp_mask);
reclaim_state.reclaimed_slab = 0;
p->reclaim_state = &reclaim_state;
@@ -2593,6 +2626,7 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
p->reclaim_state = NULL;
current->flags &= ~(PF_MEMALLOC | PF_SWAPWRITE);
+ lockdep_clear_current_reclaim_state();
return sc.nr_reclaimed >= nr_pages;
}
@@ -2615,7 +2649,7 @@ int zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
zone_page_state(zone, NR_SLAB_RECLAIMABLE) <= zone->min_slab_pages)
return ZONE_RECLAIM_FULL;
- if (zone_is_all_unreclaimable(zone))
+ if (zone->all_unreclaimable)
return ZONE_RECLAIM_FULL;
/*
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-12-28 01:30:41 +0000