Commit 3a80a7fa authored by Mel Gorman's avatar Mel Gorman Committed by Linus Torvalds

mm: meminit: initialise a subset of struct pages if CONFIG_DEFERRED_STRUCT_PAGE_INIT is set

This patch initalises all low memory struct pages and 2G of the highest
zone on each node during memory initialisation if
CONFIG_DEFERRED_STRUCT_PAGE_INIT is set.  That config option cannot be set
but will be available in a later patch.  Parallel initialisation of struct
page depends on some features from memory hotplug and it is necessary to
alter alter section annotations.
Signed-off-by: default avatarMel Gorman <mgorman@suse.de>
Tested-by: default avatarNate Zimmer <nzimmer@sgi.com>
Tested-by: default avatarWaiman Long <waiman.long@hp.com>
Tested-by: default avatarDaniel J Blueman <daniel@numascale.com>
Acked-by: default avatarPekka Enberg <penberg@kernel.org>
Cc: Robin Holt <robinmholt@gmail.com>
Cc: Nate Zimmer <nzimmer@sgi.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Waiman Long <waiman.long@hp.com>
Cc: Scott Norton <scott.norton@hp.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 75a592a4
......@@ -359,12 +359,16 @@ int unregister_cpu_under_node(unsigned int cpu, unsigned int nid)
#ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
#define page_initialized(page) (page->lru.next)
static int get_nid_for_pfn(unsigned long pfn)
static int __init_refok get_nid_for_pfn(unsigned long pfn)
{
struct page *page;
if (!pfn_valid_within(pfn))
return -1;
#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
if (system_state == SYSTEM_BOOTING)
return early_pfn_to_nid(pfn);
#endif
page = pfn_to_page(pfn);
if (!page_initialized(page))
return -1;
......
......@@ -762,6 +762,14 @@ typedef struct pglist_data {
/* Number of pages migrated during the rate limiting time interval */
unsigned long numabalancing_migrate_nr_pages;
#endif
#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
/*
* If memory initialisation on large machines is deferred then this
* is the first PFN that needs to be initialised.
*/
unsigned long first_deferred_pfn;
#endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
} pg_data_t;
#define node_present_pages(nid) (NODE_DATA(nid)->node_present_pages)
......
......@@ -636,3 +636,21 @@ config MAX_STACK_SIZE_MB
changed to a smaller value in which case that is used.
A sane initial value is 80 MB.
# For architectures that support deferred memory initialisation
config ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT
bool
config DEFERRED_STRUCT_PAGE_INIT
bool "Defer initialisation of struct pages to kswapd"
default n
depends on ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT
depends on MEMORY_HOTPLUG
help
Ordinarily all struct pages are initialised during early boot in a
single thread. On very large machines this can take a considerable
amount of time. If this option is set, large machines will bring up
a subset of memmap at boot and then initialise the rest in parallel
when kswapd starts. This has a potential performance impact on
processes running early in the lifetime of the systemm until kswapd
finishes the initialisation.
......@@ -387,6 +387,24 @@ static inline void mminit_verify_zonelist(void)
}
#endif /* CONFIG_DEBUG_MEMORY_INIT */
/*
* Deferred struct page initialisation requires init functions that are freed
* before kswapd is available. Reuse the memory hotplug section annotation
* to mark the required code.
*
* __defermem_init is code that always exists but is annotated __meminit to
* avoid section warnings.
* __defer_init code gets marked __meminit when deferring struct page
* initialistion but is otherwise in the init section.
*/
#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
#define __defermem_init __meminit
#define __defer_init __meminit
#else
#define __defermem_init
#define __defer_init __init
#endif
/* mminit_validate_memmodel_limits is independent of CONFIG_DEBUG_MEMORY_INIT */
#if defined(CONFIG_SPARSEMEM)
extern void mminit_validate_memmodel_limits(unsigned long *start_pfn,
......
......@@ -235,6 +235,64 @@ EXPORT_SYMBOL(nr_online_nodes);
int page_group_by_mobility_disabled __read_mostly;
#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
static inline void reset_deferred_meminit(pg_data_t *pgdat)
{
pgdat->first_deferred_pfn = ULONG_MAX;
}
/* Returns true if the struct page for the pfn is uninitialised */
static inline bool __defermem_init early_page_uninitialised(unsigned long pfn)
{
int nid = early_pfn_to_nid(pfn);
if (pfn >= NODE_DATA(nid)->first_deferred_pfn)
return true;
return false;
}
/*
* Returns false when the remaining initialisation should be deferred until
* later in the boot cycle when it can be parallelised.
*/
static inline bool update_defer_init(pg_data_t *pgdat,
unsigned long pfn, unsigned long zone_end,
unsigned long *nr_initialised)
{
/* Always populate low zones for address-contrained allocations */
if (zone_end < pgdat_end_pfn(pgdat))
return true;
/* Initialise at least 2G of the highest zone */
(*nr_initialised)++;
if (*nr_initialised > (2UL << (30 - PAGE_SHIFT)) &&
(pfn & (PAGES_PER_SECTION - 1)) == 0) {
pgdat->first_deferred_pfn = pfn;
return false;
}
return true;
}
#else
static inline void reset_deferred_meminit(pg_data_t *pgdat)
{
}
static inline bool early_page_uninitialised(unsigned long pfn)
{
return false;
}
static inline bool update_defer_init(pg_data_t *pgdat,
unsigned long pfn, unsigned long zone_end,
unsigned long *nr_initialised)
{
return true;
}
#endif
void set_pageblock_migratetype(struct page *page, int migratetype)
{
if (unlikely(page_group_by_mobility_disabled &&
......@@ -878,8 +936,8 @@ static void __free_pages_ok(struct page *page, unsigned int order)
local_irq_restore(flags);
}
void __init __free_pages_bootmem(struct page *page, unsigned long pfn,
unsigned int order)
static void __defer_init __free_pages_boot_core(struct page *page,
unsigned long pfn, unsigned int order)
{
unsigned int nr_pages = 1 << order;
struct page *p = page;
......@@ -951,6 +1009,14 @@ static inline bool __meminit meminit_pfn_in_nid(unsigned long pfn, int node,
#endif
void __defer_init __free_pages_bootmem(struct page *page, unsigned long pfn,
unsigned int order)
{
if (early_page_uninitialised(pfn))
return;
return __free_pages_boot_core(page, pfn, order);
}
#ifdef CONFIG_CMA
/* Free whole pageblock and set its migration type to MIGRATE_CMA. */
void __init init_cma_reserved_pageblock(struct page *page)
......@@ -4325,14 +4391,16 @@ static void setup_zone_migrate_reserve(struct zone *zone)
void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
unsigned long start_pfn, enum memmap_context context)
{
pg_data_t *pgdat = NODE_DATA(nid);
unsigned long end_pfn = start_pfn + size;
unsigned long pfn;
struct zone *z;
unsigned long nr_initialised = 0;
if (highest_memmap_pfn < end_pfn - 1)
highest_memmap_pfn = end_pfn - 1;
z = &NODE_DATA(nid)->node_zones[zone];
z = &pgdat->node_zones[zone];
for (pfn = start_pfn; pfn < end_pfn; pfn++) {
/*
* There can be holes in boot-time mem_map[]s
......@@ -4344,6 +4412,9 @@ void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
continue;
if (!early_pfn_in_nid(pfn, nid))
continue;
if (!update_defer_init(pgdat, pfn, end_pfn,
&nr_initialised))
break;
}
__init_single_pfn(pfn, zone, nid);
}
......@@ -5144,6 +5215,7 @@ void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
/* pg_data_t should be reset to zero when it's allocated */
WARN_ON(pgdat->nr_zones || pgdat->classzone_idx);
reset_deferred_meminit(pgdat);
pgdat->node_id = nid;
pgdat->node_start_pfn = node_start_pfn;
#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
......
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