aboutsummaryrefslogtreecommitdiffstats
path: root/mm/page_alloc.c
diff options
context:
space:
mode:
Diffstat (limited to 'mm/page_alloc.c')
-rw-r--r--mm/page_alloc.c275
1 files changed, 159 insertions, 116 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index ebffa0e4a9c0..5e6fa06f2784 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -380,20 +380,6 @@ void prep_compound_page(struct page *page, unsigned long order)
}
}
-static inline void prep_zero_page(struct page *page, unsigned int order,
- gfp_t gfp_flags)
-{
- int i;
-
- /*
- * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO
- * and __GFP_HIGHMEM from hard or soft interrupt context.
- */
- VM_BUG_ON((gfp_flags & __GFP_HIGHMEM) && in_interrupt());
- for (i = 0; i < (1 << order); i++)
- clear_highpage(page + i);
-}
-
#ifdef CONFIG_DEBUG_PAGEALLOC
unsigned int _debug_guardpage_minorder;
bool _debug_pagealloc_enabled __read_mostly;
@@ -975,7 +961,8 @@ static int prep_new_page(struct page *page, unsigned int order, gfp_t gfp_flags,
kasan_alloc_pages(page, order);
if (gfp_flags & __GFP_ZERO)
- prep_zero_page(page, order, gfp_flags);
+ for (i = 0; i < (1 << order); i++)
+ clear_highpage(page + i);
if (order && (gfp_flags & __GFP_COMP))
prep_compound_page(page, order);
@@ -2322,48 +2309,6 @@ void warn_alloc_failed(gfp_t gfp_mask, int order, const char *fmt, ...)
show_mem(filter);
}
-static inline int
-should_alloc_retry(gfp_t gfp_mask, unsigned int order,
- unsigned long did_some_progress,
- unsigned long pages_reclaimed)
-{
- /* Do not loop if specifically requested */
- if (gfp_mask & __GFP_NORETRY)
- return 0;
-
- /* Always retry if specifically requested */
- if (gfp_mask & __GFP_NOFAIL)
- return 1;
-
- /*
- * Suspend converts GFP_KERNEL to __GFP_WAIT which can prevent reclaim
- * making forward progress without invoking OOM. Suspend also disables
- * storage devices so kswapd will not help. Bail if we are suspending.
- */
- if (!did_some_progress && pm_suspended_storage())
- return 0;
-
- /*
- * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER
- * means __GFP_NOFAIL, but that may not be true in other
- * implementations.
- */
- if (order <= PAGE_ALLOC_COSTLY_ORDER)
- return 1;
-
- /*
- * For order > PAGE_ALLOC_COSTLY_ORDER, if __GFP_REPEAT is
- * specified, then we retry until we no longer reclaim any pages
- * (above), or we've reclaimed an order of pages at least as
- * large as the allocation's order. In both cases, if the
- * allocation still fails, we stop retrying.
- */
- if (gfp_mask & __GFP_REPEAT && pages_reclaimed < (1 << order))
- return 1;
-
- return 0;
-}
-
static inline struct page *
__alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
const struct alloc_context *ac, unsigned long *did_some_progress)
@@ -2373,10 +2318,10 @@ __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
*did_some_progress = 0;
/*
- * Acquire the per-zone oom lock for each zone. If that
- * fails, somebody else is making progress for us.
+ * Acquire the oom lock. If that fails, somebody else is
+ * making progress for us.
*/
- if (!oom_zonelist_trylock(ac->zonelist, gfp_mask)) {
+ if (!mutex_trylock(&oom_lock)) {
*did_some_progress = 1;
schedule_timeout_uninterruptible(1);
return NULL;
@@ -2402,16 +2347,18 @@ __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
/* The OOM killer does not needlessly kill tasks for lowmem */
if (ac->high_zoneidx < ZONE_NORMAL)
goto out;
- /* The OOM killer does not compensate for light reclaim */
+ /* The OOM killer does not compensate for IO-less reclaim */
if (!(gfp_mask & __GFP_FS)) {
/*
* XXX: Page reclaim didn't yield anything,
* and the OOM killer can't be invoked, but
- * keep looping as per should_alloc_retry().
+ * keep looping as per tradition.
*/
*did_some_progress = 1;
goto out;
}
+ if (pm_suspended_storage())
+ goto out;
/* The OOM killer may not free memory on a specific node */
if (gfp_mask & __GFP_THISNODE)
goto out;
@@ -2421,7 +2368,7 @@ __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
|| WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL))
*did_some_progress = 1;
out:
- oom_zonelist_unlock(ac->zonelist, gfp_mask);
+ mutex_unlock(&oom_lock);
return page;
}
@@ -2794,40 +2741,40 @@ retry:
if (page)
goto got_pg;
- /* Check if we should retry the allocation */
+ /* Do not loop if specifically requested */
+ if (gfp_mask & __GFP_NORETRY)
+ goto noretry;
+
+ /* Keep reclaiming pages as long as there is reasonable progress */
pages_reclaimed += did_some_progress;
- if (should_alloc_retry(gfp_mask, order, did_some_progress,
- pages_reclaimed)) {
- /*
- * If we fail to make progress by freeing individual
- * pages, but the allocation wants us to keep going,
- * start OOM killing tasks.
- */
- if (!did_some_progress) {
- page = __alloc_pages_may_oom(gfp_mask, order, ac,
- &did_some_progress);
- if (page)
- goto got_pg;
- if (!did_some_progress)
- goto nopage;
- }
+ if ((did_some_progress && order <= PAGE_ALLOC_COSTLY_ORDER) ||
+ ((gfp_mask & __GFP_REPEAT) && pages_reclaimed < (1 << order))) {
/* Wait for some write requests to complete then retry */
wait_iff_congested(ac->preferred_zone, BLK_RW_ASYNC, HZ/50);
goto retry;
- } else {
- /*
- * High-order allocations do not necessarily loop after
- * direct reclaim and reclaim/compaction depends on compaction
- * being called after reclaim so call directly if necessary
- */
- page = __alloc_pages_direct_compact(gfp_mask, order,
- alloc_flags, ac, migration_mode,
- &contended_compaction,
- &deferred_compaction);
- if (page)
- goto got_pg;
}
+ /* Reclaim has failed us, start killing things */
+ page = __alloc_pages_may_oom(gfp_mask, order, ac, &did_some_progress);
+ if (page)
+ goto got_pg;
+
+ /* Retry as long as the OOM killer is making progress */
+ if (did_some_progress)
+ goto retry;
+
+noretry:
+ /*
+ * High-order allocations do not necessarily loop after
+ * direct reclaim and reclaim/compaction depends on compaction
+ * being called after reclaim so call directly if necessary
+ */
+ page = __alloc_pages_direct_compact(gfp_mask, order, alloc_flags,
+ ac, migration_mode,
+ &contended_compaction,
+ &deferred_compaction);
+ if (page)
+ goto got_pg;
nopage:
warn_alloc_failed(gfp_mask, order, NULL);
got_pg:
@@ -2967,6 +2914,104 @@ void free_pages(unsigned long addr, unsigned int order)
EXPORT_SYMBOL(free_pages);
/*
+ * Page Fragment:
+ * An arbitrary-length arbitrary-offset area of memory which resides
+ * within a 0 or higher order page. Multiple fragments within that page
+ * are individually refcounted, in the page's reference counter.
+ *
+ * The page_frag functions below provide a simple allocation framework for
+ * page fragments. This is used by the network stack and network device
+ * drivers to provide a backing region of memory for use as either an
+ * sk_buff->head, or to be used in the "frags" portion of skb_shared_info.
+ */
+static struct page *__page_frag_refill(struct page_frag_cache *nc,
+ gfp_t gfp_mask)
+{
+ struct page *page = NULL;
+ gfp_t gfp = gfp_mask;
+
+#if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
+ gfp_mask |= __GFP_COMP | __GFP_NOWARN | __GFP_NORETRY |
+ __GFP_NOMEMALLOC;
+ page = alloc_pages_node(NUMA_NO_NODE, gfp_mask,
+ PAGE_FRAG_CACHE_MAX_ORDER);
+ nc->size = page ? PAGE_FRAG_CACHE_MAX_SIZE : PAGE_SIZE;
+#endif
+ if (unlikely(!page))
+ page = alloc_pages_node(NUMA_NO_NODE, gfp, 0);
+
+ nc->va = page ? page_address(page) : NULL;
+
+ return page;
+}
+
+void *__alloc_page_frag(struct page_frag_cache *nc,
+ unsigned int fragsz, gfp_t gfp_mask)
+{
+ unsigned int size = PAGE_SIZE;
+ struct page *page;
+ int offset;
+
+ if (unlikely(!nc->va)) {
+refill:
+ page = __page_frag_refill(nc, gfp_mask);
+ if (!page)
+ return NULL;
+
+#if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
+ /* if size can vary use size else just use PAGE_SIZE */
+ size = nc->size;
+#endif
+ /* Even if we own the page, we do not use atomic_set().
+ * This would break get_page_unless_zero() users.
+ */
+ atomic_add(size - 1, &page->_count);
+
+ /* reset page count bias and offset to start of new frag */
+ nc->pfmemalloc = page->pfmemalloc;
+ nc->pagecnt_bias = size;
+ nc->offset = size;
+ }
+
+ offset = nc->offset - fragsz;
+ if (unlikely(offset < 0)) {
+ page = virt_to_page(nc->va);
+
+ if (!atomic_sub_and_test(nc->pagecnt_bias, &page->_count))
+ goto refill;
+
+#if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
+ /* if size can vary use size else just use PAGE_SIZE */
+ size = nc->size;
+#endif
+ /* OK, page count is 0, we can safely set it */
+ atomic_set(&page->_count, size);
+
+ /* reset page count bias and offset to start of new frag */
+ nc->pagecnt_bias = size;
+ offset = size - fragsz;
+ }
+
+ nc->pagecnt_bias--;
+ nc->offset = offset;
+
+ return nc->va + offset;
+}
+EXPORT_SYMBOL(__alloc_page_frag);
+
+/*
+ * Frees a page fragment allocated out of either a compound or order 0 page.
+ */
+void __free_page_frag(void *addr)
+{
+ struct page *page = virt_to_head_page(addr);
+
+ if (unlikely(put_page_testzero(page)))
+ __free_pages_ok(page, compound_order(page));
+}
+EXPORT_SYMBOL(__free_page_frag);
+
+/*
* alloc_kmem_pages charges newly allocated pages to the kmem resource counter
* of the current memory cgroup.
*
@@ -4769,22 +4814,28 @@ static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
unsigned long *zones_size,
unsigned long *zholes_size)
{
- unsigned long realtotalpages, totalpages = 0;
+ unsigned long realtotalpages = 0, totalpages = 0;
enum zone_type i;
- for (i = 0; i < MAX_NR_ZONES; i++)
- totalpages += zone_spanned_pages_in_node(pgdat->node_id, i,
- node_start_pfn,
- node_end_pfn,
- zones_size);
- pgdat->node_spanned_pages = totalpages;
-
- realtotalpages = totalpages;
- for (i = 0; i < MAX_NR_ZONES; i++)
- realtotalpages -=
- zone_absent_pages_in_node(pgdat->node_id, i,
+ for (i = 0; i < MAX_NR_ZONES; i++) {
+ struct zone *zone = pgdat->node_zones + i;
+ unsigned long size, real_size;
+
+ size = zone_spanned_pages_in_node(pgdat->node_id, i,
+ node_start_pfn,
+ node_end_pfn,
+ zones_size);
+ real_size = size - zone_absent_pages_in_node(pgdat->node_id, i,
node_start_pfn, node_end_pfn,
zholes_size);
+ zone->spanned_pages = size;
+ zone->present_pages = real_size;
+
+ totalpages += size;
+ realtotalpages += real_size;
+ }
+
+ pgdat->node_spanned_pages = totalpages;
pgdat->node_present_pages = realtotalpages;
printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id,
realtotalpages);
@@ -4894,8 +4945,7 @@ static unsigned long __paginginit calc_memmap_size(unsigned long spanned_pages,
* NOTE: pgdat should get zeroed by caller.
*/
static void __paginginit free_area_init_core(struct pglist_data *pgdat,
- unsigned long node_start_pfn, unsigned long node_end_pfn,
- unsigned long *zones_size, unsigned long *zholes_size)
+ unsigned long node_start_pfn, unsigned long node_end_pfn)
{
enum zone_type j;
int nid = pgdat->node_id;
@@ -4916,12 +4966,8 @@ static void __paginginit free_area_init_core(struct pglist_data *pgdat,
struct zone *zone = pgdat->node_zones + j;
unsigned long size, realsize, freesize, memmap_pages;
- size = zone_spanned_pages_in_node(nid, j, node_start_pfn,
- node_end_pfn, zones_size);
- realsize = freesize = size - zone_absent_pages_in_node(nid, j,
- node_start_pfn,
- node_end_pfn,
- zholes_size);
+ size = zone->spanned_pages;
+ realsize = freesize = zone->present_pages;
/*
* Adjust freesize so that it accounts for how much memory
@@ -4956,8 +5002,6 @@ static void __paginginit free_area_init_core(struct pglist_data *pgdat,
nr_kernel_pages -= memmap_pages;
nr_all_pages += freesize;
- zone->spanned_pages = size;
- zone->present_pages = realsize;
/*
* Set an approximate value for lowmem here, it will be adjusted
* when the bootmem allocator frees pages into the buddy system.
@@ -5063,8 +5107,7 @@ void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
(unsigned long)pgdat->node_mem_map);
#endif
- free_area_init_core(pgdat, start_pfn, end_pfn,
- zones_size, zholes_size);
+ free_area_init_core(pgdat, start_pfn, end_pfn);
}
#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
@@ -6013,9 +6056,9 @@ out:
return ret;
}
+#ifdef CONFIG_NUMA
int hashdist = HASHDIST_DEFAULT;
-#ifdef CONFIG_NUMA
static int __init set_hashdist(char *str)
{
if (!str)