mm, treewide: introduce NR_PAGE_ORDERS

NR_PAGE_ORDERS defines the number of page orders supported by the page
allocator, ranging from 0 to MAX_ORDER, MAX_ORDER + 1 in total.

NR_PAGE_ORDERS assists in defining arrays of page orders and allows for
more natural iteration over them.

[kirill.shutemov@linux.intel.com: fixup for kerneldoc warning]
Link: https://lkml.kernel.org/r/20240101111512.7empzyifq7kxtzk3@box
Link: https://lkml.kernel.org/r/20231228144704.14033-1-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/Documentation/admin-guide/kdump/vmcoreinfo.rst b/Documentation/admin-guide/kdump/vmcoreinfo.rst
index 78e4d2e7ba1447c12ef7f99a08cdb4706c5dc1cd..3f8769e46b07ac830223345254745ae31659d195 100644 (file)
--- a/Documentation/admin-guide/kdump/vmcoreinfo.rst
+++ b/Documentation/admin-guide/kdump/vmcoreinfo.rst
@@ -172,7 +172,7 @@ variables.
 Offset of the free_list's member. This value is used to compute the number
 of free pages.
 
-Each zone has a free_area structure array called free_area[MAX_ORDER + 1].
+Each zone has a free_area structure array called free_area[NR_PAGE_ORDERS].
 The free_list represents a linked list of free page blocks.
 
 (list_head, next|prev)
@@ -189,8 +189,8 @@ Offsets of the vmap_area's members. They carry vmalloc-specific
 information. Makedumpfile gets the start address of the vmalloc region
 from this.
 
-(zone.free_area, MAX_ORDER + 1)
--------------------------------
+(zone.free_area, NR_PAGE_ORDERS)
+--------------------------------
 
 Free areas descriptor. User-space tools use this value to iterate the
 free_area ranges. MAX_ORDER is used by the zone buddy allocator.

diff --git a/arch/arm64/kvm/hyp/include/nvhe/gfp.h b/arch/arm64/kvm/hyp/include/nvhe/gfp.h
index fe5472a184a37d83c5dde7c14c92e559e3d92f3b..97c527ef53c2adeab264d9495ba380dfabcaa025 100644 (file)
--- a/arch/arm64/kvm/hyp/include/nvhe/gfp.h
+++ b/arch/arm64/kvm/hyp/include/nvhe/gfp.h
@@ -16,7 +16,7 @@ struct hyp_pool {
         * API at EL2.
         */
        hyp_spinlock_t lock;
-       struct list_head free_area[MAX_ORDER + 1];
+       struct list_head free_area[NR_PAGE_ORDERS];
        phys_addr_t range_start;
        phys_addr_t range_end;
        unsigned short max_order;

diff --git a/arch/sparc/kernel/traps_64.c b/arch/sparc/kernel/traps_64.c
index 08ffd17d5ec34050bdda1d80d927a60ebe5cc99e..523a6e5ee9251936b5d49a97e2c65d811ae85d7c 100644 (file)
--- a/arch/sparc/kernel/traps_64.c
+++ b/arch/sparc/kernel/traps_64.c
@@ -897,7 +897,7 @@ void __init cheetah_ecache_flush_init(void)
 
        /* Now allocate error trap reporting scoreboard. */
        sz = NR_CPUS * (2 * sizeof(struct cheetah_err_info));
-       for (order = 0; order <= MAX_ORDER; order++) {
+       for (order = 0; order < NR_PAGE_ORDERS; order++) {
                if ((PAGE_SIZE << order) >= sz)
                        break;
        }

diff --git a/drivers/gpu/drm/ttm/tests/ttm_device_test.c b/drivers/gpu/drm/ttm/tests/ttm_device_test.c
index b1b423b68cdf1654678c94befb27c8ebe828d7a9..19eaff22e6ae04ddec69b5a4fc5a490f0e01d289 100644 (file)
--- a/drivers/gpu/drm/ttm/tests/ttm_device_test.c
+++ b/drivers/gpu/drm/ttm/tests/ttm_device_test.c
@@ -175,7 +175,7 @@ static void ttm_device_init_pools(struct kunit *test)
 
        if (params->pools_init_expected) {
                for (int i = 0; i < TTM_NUM_CACHING_TYPES; ++i) {
-                       for (int j = 0; j <= MAX_ORDER; ++j) {
+                       for (int j = 0; j < NR_PAGE_ORDERS; ++j) {
                                pt = pool->caching[i].orders[j];
                                KUNIT_EXPECT_PTR_EQ(test, pt.pool, pool);
                                KUNIT_EXPECT_EQ(test, pt.caching, i);

diff --git a/drivers/gpu/drm/ttm/ttm_pool.c b/drivers/gpu/drm/ttm/ttm_pool.c
index fe610a3cace00b63025fb0d59bfb5e8588e15ed3..d183bb97c526cba4b78bd5e413b7e5cf85bb3d84 100644 (file)
--- a/drivers/gpu/drm/ttm/ttm_pool.c
+++ b/drivers/gpu/drm/ttm/ttm_pool.c
@@ -65,11 +65,11 @@ module_param(page_pool_size, ulong, 0644);
 
 static atomic_long_t allocated_pages;
 
-static struct ttm_pool_type global_write_combined[MAX_ORDER + 1];
-static struct ttm_pool_type global_uncached[MAX_ORDER + 1];
+static struct ttm_pool_type global_write_combined[NR_PAGE_ORDERS];
+static struct ttm_pool_type global_uncached[NR_PAGE_ORDERS];
 
-static struct ttm_pool_type global_dma32_write_combined[MAX_ORDER + 1];
-static struct ttm_pool_type global_dma32_uncached[MAX_ORDER + 1];
+static struct ttm_pool_type global_dma32_write_combined[NR_PAGE_ORDERS];
+static struct ttm_pool_type global_dma32_uncached[NR_PAGE_ORDERS];
 
 static spinlock_t shrinker_lock;
 static struct list_head shrinker_list;
@@ -568,7 +568,7 @@ void ttm_pool_init(struct ttm_pool *pool, struct device *dev,
 
        if (use_dma_alloc || nid != NUMA_NO_NODE) {
                for (i = 0; i < TTM_NUM_CACHING_TYPES; ++i)
-                       for (j = 0; j <= MAX_ORDER; ++j)
+                       for (j = 0; j < NR_PAGE_ORDERS; ++j)
                                ttm_pool_type_init(&pool->caching[i].orders[j],
                                                   pool, i, j);
        }
@@ -601,7 +601,7 @@ void ttm_pool_fini(struct ttm_pool *pool)
 
        if (pool->use_dma_alloc || pool->nid != NUMA_NO_NODE) {
                for (i = 0; i < TTM_NUM_CACHING_TYPES; ++i)
-                       for (j = 0; j <= MAX_ORDER; ++j)
+                       for (j = 0; j < NR_PAGE_ORDERS; ++j)
                                ttm_pool_type_fini(&pool->caching[i].orders[j]);
        }
 
@@ -656,7 +656,7 @@ static void ttm_pool_debugfs_header(struct seq_file *m)
        unsigned int i;
 
        seq_puts(m, "\t ");
-       for (i = 0; i <= MAX_ORDER; ++i)
+       for (i = 0; i < NR_PAGE_ORDERS; ++i)
                seq_printf(m, " ---%2u---", i);
        seq_puts(m, "\n");
 }
@@ -667,7 +667,7 @@ static void ttm_pool_debugfs_orders(struct ttm_pool_type *pt,
 {
        unsigned int i;
 
-       for (i = 0; i <= MAX_ORDER; ++i)
+       for (i = 0; i < NR_PAGE_ORDERS; ++i)
                seq_printf(m, " %8u", ttm_pool_type_count(&pt[i]));
        seq_puts(m, "\n");
 }
@@ -776,7 +776,7 @@ int ttm_pool_mgr_init(unsigned long num_pages)
        spin_lock_init(&shrinker_lock);
        INIT_LIST_HEAD(&shrinker_list);
 
-       for (i = 0; i <= MAX_ORDER; ++i) {
+       for (i = 0; i < NR_PAGE_ORDERS; ++i) {
                ttm_pool_type_init(&global_write_combined[i], NULL,
                                   ttm_write_combined, i);
                ttm_pool_type_init(&global_uncached[i], NULL, ttm_uncached, i);
@@ -816,7 +816,7 @@ void ttm_pool_mgr_fini(void)
 {
        unsigned int i;
 
-       for (i = 0; i <= MAX_ORDER; ++i) {
+       for (i = 0; i < NR_PAGE_ORDERS; ++i) {
                ttm_pool_type_fini(&global_write_combined[i]);
                ttm_pool_type_fini(&global_uncached[i]);
 

diff --git a/include/drm/ttm/ttm_pool.h b/include/drm/ttm/ttm_pool.h
index 30a347e5aa114921cdb548d3f69df73bcdf71f7e..4490d43c63e33b3b657567e1bd5e5c17e260f1c9 100644 (file)
--- a/include/drm/ttm/ttm_pool.h
+++ b/include/drm/ttm/ttm_pool.h
@@ -74,7 +74,7 @@ struct ttm_pool {
        bool use_dma32;
 
        struct {
-               struct ttm_pool_type orders[MAX_ORDER + 1];
+               struct ttm_pool_type orders[NR_PAGE_ORDERS];
        } caching[TTM_NUM_CACHING_TYPES];
 };
 

diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index c18c53353b50f0152deebc22d95aab24f465e72a..1ea7636dfb7659b027c6d246160ac0e4541689aa 100644 (file)
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -35,6 +35,8 @@
 
 #define IS_MAX_ORDER_ALIGNED(pfn) IS_ALIGNED(pfn, MAX_ORDER_NR_PAGES)
 
+#define NR_PAGE_ORDERS (MAX_ORDER + 1)
+
 /*
  * PAGE_ALLOC_COSTLY_ORDER is the order at which allocations are deemed
  * costly to service.  That is between allocation orders which should
@@ -96,7 +98,7 @@ static inline bool migratetype_is_mergeable(int mt)
 }
 
 #define for_each_migratetype_order(order, type) \
-       for (order = 0; order <= MAX_ORDER; order++) \
+       for (order = 0; order < NR_PAGE_ORDERS; order++) \
                for (type = 0; type < MIGRATE_TYPES; type++)
 
 extern int page_group_by_mobility_disabled;
@@ -933,7 +935,7 @@ struct zone {
        CACHELINE_PADDING(_pad1_);
 
        /* free areas of different sizes */
-       struct free_area        free_area[MAX_ORDER + 1];
+       struct free_area        free_area[NR_PAGE_ORDERS];
 
 #ifdef CONFIG_UNACCEPTED_MEMORY
        /* Pages to be accepted. All pages on the list are MAX_ORDER */

diff --git a/kernel/crash_core.c b/kernel/crash_core.c
index d4313b53837e3de5bb42b553152b086b5d0657ef..56cf4ad7abbba9917211ae99c78a6f7b545341e2 100644 (file)
--- a/kernel/crash_core.c
+++ b/kernel/crash_core.c
@@ -802,7 +802,7 @@ static int __init crash_save_vmcoreinfo_init(void)
        VMCOREINFO_OFFSET(list_head, prev);
        VMCOREINFO_OFFSET(vmap_area, va_start);
        VMCOREINFO_OFFSET(vmap_area, list);
-       VMCOREINFO_LENGTH(zone.free_area, MAX_ORDER + 1);
+       VMCOREINFO_LENGTH(zone.free_area, NR_PAGE_ORDERS);
        log_buf_vmcoreinfo_setup();
        VMCOREINFO_LENGTH(free_area.free_list, MIGRATE_TYPES);
        VMCOREINFO_NUMBER(NR_FREE_PAGES);

diff --git a/lib/test_meminit.c b/lib/test_meminit.c
index 0ae35223d7733573b19b4997668e08d45359bb03..0dc173849a5420f3f704f272e94b03205edfc1e1 100644 (file)
--- a/lib/test_meminit.c
+++ b/lib/test_meminit.c
@@ -93,7 +93,7 @@ static int __init test_pages(int *total_failures)
        int failures = 0, num_tests = 0;
        int i;
 
-       for (i = 0; i <= MAX_ORDER; i++)
+       for (i = 0; i < NR_PAGE_ORDERS; i++)
                num_tests += do_alloc_pages_order(i, &failures);
 
        REPORT_FAILURES_IN_FN();

diff --git a/mm/compaction.c b/mm/compaction.c
index de15a2ef0af57810036910b50ff70b14dbfd3cad..24f8eb4d62604cfb71fb4b2f4892040bae0d8764 100644 (file)
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -2229,7 +2229,7 @@ static enum compact_result __compact_finished(struct compact_control *cc)
 
        /* Direct compactor: Is a suitable page free? */
        ret = COMPACT_NO_SUITABLE_PAGE;
-       for (order = cc->order; order <= MAX_ORDER; order++) {
+       for (order = cc->order; order < NR_PAGE_ORDERS; order++) {
                struct free_area *area = &cc->zone->free_area[order];
                bool can_steal;
 

diff --git a/mm/kmsan/init.c b/mm/kmsan/init.c
index ffedf4dbc49d77c25bc9107f8203cf7ca16df72d..103e2e88ea033f86743d588159983d964964d3be 100644 (file)
--- a/mm/kmsan/init.c
+++ b/mm/kmsan/init.c
@@ -96,7 +96,7 @@ void __init kmsan_init_shadow(void)
 struct metadata_page_pair {
        struct page *shadow, *origin;
 };
-static struct metadata_page_pair held_back[MAX_ORDER + 1] __initdata;
+static struct metadata_page_pair held_back[NR_PAGE_ORDERS] __initdata;
 
 /*
  * Eager metadata allocation. When the memblock allocator is freeing pages to

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 5526797b7f960d6ee10e9cb0405f3570f46e081f..ccecf6158ae43b2d4ae7316743de123b1c04638f 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1560,7 +1560,7 @@ struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
        struct page *page;
 
        /* Find a page of the appropriate size in the preferred list */
-       for (current_order = order; current_order <= MAX_ORDER; ++current_order) {
+       for (current_order = order; current_order < NR_PAGE_ORDERS; ++current_order) {
                area = &(zone->free_area[current_order]);
                page = get_page_from_free_area(area, migratetype);
                if (!page)
@@ -1934,7 +1934,7 @@ static bool unreserve_highatomic_pageblock(const struct alloc_context *ac,
                        continue;
 
                spin_lock_irqsave(&zone->lock, flags);
-               for (order = 0; order <= MAX_ORDER; order++) {
+               for (order = 0; order < NR_PAGE_ORDERS; order++) {
                        struct free_area *area = &(zone->free_area[order]);
 
                        page = get_page_from_free_area(area, MIGRATE_HIGHATOMIC);
@@ -2044,8 +2044,7 @@ __rmqueue_fallback(struct zone *zone, int order, int start_migratetype,
        return false;
 
 find_smallest:
-       for (current_order = order; current_order <= MAX_ORDER;
-                                                       current_order++) {
+       for (current_order = order; current_order < NR_PAGE_ORDERS; current_order++) {
                area = &(zone->free_area[current_order]);
                fallback_mt = find_suitable_fallback(area, current_order,
                                start_migratetype, false, &can_steal);
@@ -3000,7 +2999,7 @@ bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
                return true;
 
        /* For a high-order request, check at least one suitable page is free */
-       for (o = order; o <= MAX_ORDER; o++) {
+       for (o = order; o < NR_PAGE_ORDERS; o++) {
                struct free_area *area = &z->free_area[o];
                int mt;
 
@@ -6628,7 +6627,7 @@ bool is_free_buddy_page(struct page *page)
        unsigned long pfn = page_to_pfn(page);
        unsigned int order;
 
-       for (order = 0; order <= MAX_ORDER; order++) {
+       for (order = 0; order < NR_PAGE_ORDERS; order++) {
                struct page *page_head = page - (pfn & ((1 << order) - 1));
 
                if (PageBuddy(page_head) &&
@@ -6683,7 +6682,7 @@ bool take_page_off_buddy(struct page *page)
        bool ret = false;
 
        spin_lock_irqsave(&zone->lock, flags);
-       for (order = 0; order <= MAX_ORDER; order++) {
+       for (order = 0; order < NR_PAGE_ORDERS; order++) {
                struct page *page_head = page - (pfn & ((1 << order) - 1));
                int page_order = buddy_order(page_head);
 

diff --git a/mm/page_reporting.c b/mm/page_reporting.c
index b021f482a4cb364afbf33ec078c3a7aadc731817..66369cc5279bf419f3180c44b219f16677929255 100644 (file)
--- a/mm/page_reporting.c
+++ b/mm/page_reporting.c
@@ -276,7 +276,7 @@ page_reporting_process_zone(struct page_reporting_dev_info *prdev,
                return err;
 
        /* Process each free list starting from lowest order/mt */
-       for (order = page_reporting_order; order <= MAX_ORDER; order++) {
+       for (order = page_reporting_order; order < NR_PAGE_ORDERS; order++) {
                for (mt = 0; mt < MIGRATE_TYPES; mt++) {
                        /* We do not pull pages from the isolate free list */
                        if (is_migrate_isolate(mt))

diff --git a/mm/show_mem.c b/mm/show_mem.c
index ba0808d6917f930e5b112f680d1ad7896741f6c5..8dcfafbd283c12a9f7ea1ad5b338848d9897a651 100644 (file)
--- a/mm/show_mem.c
+++ b/mm/show_mem.c
@@ -352,8 +352,8 @@ static void show_free_areas(unsigned int filter, nodemask_t *nodemask, int max_z
 
        for_each_populated_zone(zone) {
                unsigned int order;
-               unsigned long nr[MAX_ORDER + 1], flags, total = 0;
-               unsigned char types[MAX_ORDER + 1];
+               unsigned long nr[NR_PAGE_ORDERS], flags, total = 0;
+               unsigned char types[NR_PAGE_ORDERS];
 
                if (zone_idx(zone) > max_zone_idx)
                        continue;
@@ -363,7 +363,7 @@ static void show_free_areas(unsigned int filter, nodemask_t *nodemask, int max_z
                printk(KERN_CONT "%s: ", zone->name);
 
                spin_lock_irqsave(&zone->lock, flags);
-               for (order = 0; order <= MAX_ORDER; order++) {
+               for (order = 0; order < NR_PAGE_ORDERS; order++) {
                        struct free_area *area = &zone->free_area[order];
                        int type;
 
@@ -377,7 +377,7 @@ static void show_free_areas(unsigned int filter, nodemask_t *nodemask, int max_z
                        }
                }
                spin_unlock_irqrestore(&zone->lock, flags);
-               for (order = 0; order <= MAX_ORDER; order++) {
+               for (order = 0; order < NR_PAGE_ORDERS; order++) {
                        printk(KERN_CONT "%lu*%lukB ",
                               nr[order], K(1UL) << order);
                        if (nr[order])

diff --git a/mm/vmstat.c b/mm/vmstat.c
index 1437ca2f28c5fa1fd9a1b096dbe625d94a7dffc4..03ead31c46a01af32fa43335b7e36cb0f182e113 100644 (file)
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -1059,7 +1059,7 @@ static void fill_contig_page_info(struct zone *zone,
        info->free_blocks_total = 0;
        info->free_blocks_suitable = 0;
 
-       for (order = 0; order <= MAX_ORDER; order++) {
+       for (order = 0; order < NR_PAGE_ORDERS; order++) {
                unsigned long blocks;
 
                /*
@@ -1476,7 +1476,7 @@ static void frag_show_print(struct seq_file *m, pg_data_t *pgdat,
        int order;
 
        seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
-       for (order = 0; order <= MAX_ORDER; ++order)
+       for (order = 0; order < NR_PAGE_ORDERS; ++order)
                /*
                 * Access to nr_free is lockless as nr_free is used only for
                 * printing purposes. Use data_race to avoid KCSAN warning.
@@ -1505,7 +1505,7 @@ static void pagetypeinfo_showfree_print(struct seq_file *m,
                                        pgdat->node_id,
                                        zone->name,
                                        migratetype_names[mtype]);
-               for (order = 0; order <= MAX_ORDER; ++order) {
+               for (order = 0; order < NR_PAGE_ORDERS; ++order) {
                        unsigned long freecount = 0;
                        struct free_area *area;
                        struct list_head *curr;
@@ -1545,7 +1545,7 @@ static void pagetypeinfo_showfree(struct seq_file *m, void *arg)
 
        /* Print header */
        seq_printf(m, "%-43s ", "Free pages count per migrate type at order");
-       for (order = 0; order <= MAX_ORDER; ++order)
+       for (order = 0; order < NR_PAGE_ORDERS; ++order)
                seq_printf(m, "%6d ", order);
        seq_putc(m, '\n');
 
@@ -2181,7 +2181,7 @@ static void unusable_show_print(struct seq_file *m,
        seq_printf(m, "Node %d, zone %8s ",
                                pgdat->node_id,
                                zone->name);
-       for (order = 0; order <= MAX_ORDER; ++order) {
+       for (order = 0; order < NR_PAGE_ORDERS; ++order) {
                fill_contig_page_info(zone, order, &info);
                index = unusable_free_index(order, &info);
                seq_printf(m, "%d.%03d ", index / 1000, index % 1000);
@@ -2233,7 +2233,7 @@ static void extfrag_show_print(struct seq_file *m,
        seq_printf(m, "Node %d, zone %8s ",
                                pgdat->node_id,
                                zone->name);
-       for (order = 0; order <= MAX_ORDER; ++order) {
+       for (order = 0; order < NR_PAGE_ORDERS; ++order) {
                fill_contig_page_info(zone, order, &info);
                index = __fragmentation_index(order, &info);
                seq_printf(m, "%2d.%03d ", index / 1000, index % 1000);