Re: [RFC PATCH 13/15] mm: convert MAX_ORDER sized static arrays to dynamic ones.

Am 05.08.21 um 21:02 schrieb Zi Yan:

From: Zi Yan ziy@nvidia.com

This prepares for the upcoming changes to make MAX_ORDER a boot time parameter instead of compilation time constant. All static arrays with MAX_ORDER size are converted to pointers and their memory is allocated at runtime.

Well in general I strongly suggest to not use the patter kmalloc(sizeof(some struct) * MAX_ORDER,...) instead use kmalloc_array, kcalloc etc..

Then when a array is embedded at the end of a structure you can use a trailing array and the struct_size() macro to determine the allocation size.

Additional to that separating the patch into changes for TTM to make the maximum allocation order independent from MAX_ORDER would be rather good to have I think.

Regards, Christian.

free_area array in struct zone is allocated using memblock_alloc_node() at boot time and using kzalloc() when memory is hot-added.

MAX_ORDER in arm64 nVHE code is independent of kernel buddy allocator, so use CONFIG_FORCE_MAX_ZONEORDER instead.

Signed-off-by: Zi Yan ziy@nvidia.com Cc: Dave Young dyoung@redhat.com Cc: Jonathan Corbet corbet@lwn.net Cc: Christian Koenig christian.koenig@amd.com Cc: David Airlie airlied@linux.ie Cc: kexec@lists.infradead.org Cc: linux-doc@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Cc: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org

---

.../admin-guide/kdump/vmcoreinfo.rst | 2 +- drivers/gpu/drm/ttm/ttm_device.c | 7 ++- drivers/gpu/drm/ttm/ttm_pool.c | 58 +++++++++++++++++-- include/drm/ttm/ttm_pool.h | 4 +- include/linux/memory_hotplug.h | 1 + include/linux/mmzone.h | 2 +- mm/memory_hotplug.c | 1 + mm/page_alloc.c | 48 ++++++++++++--- 8 files changed, 104 insertions(+), 19 deletions(-)

diff --git a/Documentation/admin-guide/kdump/vmcoreinfo.rst b/Documentation/admin-guide/kdump/vmcoreinfo.rst index 3861a25faae1..1c9449b9458f 100644 --- 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]. +Each zone has a free_area structure array called free_area with length of MAX_ORDER. The free_list represents a linked list of free page blocks.

(list_head, next|prev) diff --git a/drivers/gpu/drm/ttm/ttm_device.c b/drivers/gpu/drm/ttm/ttm_device.c index 74e3b460132b..7d994c03fbd0 100644 --- a/drivers/gpu/drm/ttm/ttm_device.c +++ b/drivers/gpu/drm/ttm/ttm_device.c @@ -94,7 +94,9 @@ static int ttm_global_init(void) >> PAGE_SHIFT; num_dma32 = min(num_dma32, 2UL << (30 - PAGE_SHIFT));

• ttm_pool_mgr_init(num_pages);

• ret = ttm_pool_mgr_init(num_pages);

• if (ret)

• goto out;
  

  ttm_tt_mgr_init(num_pages, num_dma32);

  glob->dummy_read_page = alloc_page(__GFP_ZERO | GFP_DMA32);

@@ -216,7 +218,8 @@ int ttm_device_init(struct ttm_device *bdev, struct ttm_device_funcs *funcs, bdev->funcs = funcs;

ttm_sys_man_init(bdev);

• ttm_pool_init(&bdev->pool, dev, use_dma_alloc, use_dma32);

• if (ttm_pool_init(&bdev->pool, dev, use_dma_alloc, use_dma32))

• return -ENOMEM;
  
  

  bdev->vma_manager = vma_manager; INIT_DELAYED_WORK(&bdev->wq, ttm_device_delayed_workqueue);

diff --git a/drivers/gpu/drm/ttm/ttm_pool.c b/drivers/gpu/drm/ttm/ttm_pool.c index cb38b1a17b09..ae20c80f14a4 100644 --- a/drivers/gpu/drm/ttm/ttm_pool.c +++ b/drivers/gpu/drm/ttm/ttm_pool.c @@ -64,11 +64,11 @@ module_param(page_pool_size, ulong, 0644);

static atomic_long_t allocated_pages;

-static struct ttm_pool_type global_write_combined[MAX_ORDER]; -static struct ttm_pool_type global_uncached[MAX_ORDER]; +static struct ttm_pool_type *global_write_combined; +static struct ttm_pool_type *global_uncached;

-static struct ttm_pool_type global_dma32_write_combined[MAX_ORDER]; -static struct ttm_pool_type global_dma32_uncached[MAX_ORDER]; +static struct ttm_pool_type *global_dma32_write_combined; +static struct ttm_pool_type *global_dma32_uncached;

static struct mutex shrinker_lock; static struct list_head shrinker_list; @@ -493,8 +493,10 @@ EXPORT_SYMBOL(ttm_pool_free);

• @use_dma32: true if GFP_DMA32 should be used
• Initialize the pool and its pool types.

• • Returns: 0 on successe, negative error code otherwise
  */

-void ttm_pool_init(struct ttm_pool *pool, struct device *dev, +int ttm_pool_init(struct ttm_pool *pool, struct device *dev, bool use_dma_alloc, bool use_dma32) { unsigned int i, j; @@ -506,11 +508,30 @@ void ttm_pool_init(struct ttm_pool *pool, struct device *dev, pool->use_dma32 = use_dma32;

if (use_dma_alloc) {

• for (i = 0; i < TTM_NUM_CACHING_TYPES; ++i)
  

• for (i = 0; i < TTM_NUM_CACHING_TYPES; ++i) {
  

• 	pool->caching[i].orders =
  

• 		kzalloc(sizeof(struct ttm_pool_type) * MAX_ORDER,
  

• 			GFP_KERNEL);
  

• 	if (!pool->caching[i].orders) {
  

• 		i--;
  

• 		goto failed;
  

• 	}
  for (j = 0; j < MAX_ORDER; ++j)
  	ttm_pool_type_init(&pool->caching[i].orders[j],
  			   pool, i, j);
  

• }
  

• return 0;
  

+failed:

• for (; i >= 0; i--) {
  

• 	for (j = 0; j < MAX_ORDER; ++j)
  

• 		ttm_pool_type_fini(&pool->caching[i].orders[j]);
  

• 	kfree(pool->caching[i].orders);
  

• }
  

• return -ENOMEM;
  

  }

• return 0; }

  /**

@@ -696,6 +717,31 @@ int ttm_pool_mgr_init(unsigned long num_pages) mutex_init(&shrinker_lock); INIT_LIST_HEAD(&shrinker_list);

• if (!global_write_combined) {

• global_write_combined = kzalloc(sizeof(struct ttm_pool_type) * MAX_ORDER,
  

• 				GFP_KERNEL);
  

• if (!global_write_combined)
  

• 	return -ENOMEM;
  

• }
• if (!global_uncached) {

• global_uncached = kzalloc(sizeof(struct ttm_pool_type) * MAX_ORDER,
  

• 			  GFP_KERNEL);
  

• if (!global_uncached)
  

• 	return -ENOMEM;
  

• }
• if (!global_dma32_write_combined) {

• global_dma32_write_combined = kzalloc(sizeof(struct ttm_pool_type) * MAX_ORDER,
  

• 				      GFP_KERNEL);
  

• if (!global_dma32_write_combined)
  

• 	return -ENOMEM;
  

• }
• if (!global_dma32_uncached) {

• global_dma32_uncached = kzalloc(sizeof(struct ttm_pool_type) * MAX_ORDER,
  

• 				GFP_KERNEL);
  

• if (!global_dma32_uncached)
  

• 	return -ENOMEM;
  

• }
• for (i = 0; i < MAX_ORDER; ++i) { ttm_pool_type_init(&global_write_combined[i], NULL, ttm_write_combined, i);

diff --git a/include/drm/ttm/ttm_pool.h b/include/drm/ttm/ttm_pool.h index 4321728bdd11..5c09e3cf63ce 100644 --- a/include/drm/ttm/ttm_pool.h +++ b/include/drm/ttm/ttm_pool.h @@ -71,7 +71,7 @@ struct ttm_pool { bool use_dma32;

struct {

• struct ttm_pool_type orders[MAX_ORDER];
  

• struct ttm_pool_type *orders;
  

  } caching[TTM_NUM_CACHING_TYPES]; };

@@ -79,7 +79,7 @@ int ttm_pool_alloc(struct ttm_pool *pool, struct ttm_tt *tt, struct ttm_operation_ctx *ctx); void ttm_pool_free(struct ttm_pool *pool, struct ttm_tt *tt);

-void ttm_pool_init(struct ttm_pool *pool, struct device *dev, +int ttm_pool_init(struct ttm_pool *pool, struct device *dev, bool use_dma_alloc, bool use_dma32); void ttm_pool_fini(struct ttm_pool *pool);

diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index 97f874a60607..c16aa66db61e 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -326,6 +326,7 @@ extern void clear_zone_contiguous(struct zone *zone);

#ifdef CONFIG_MEMORY_HOTPLUG extern void __ref free_area_init_core_hotplug(int nid); +extern void __ref free_area_deinit_core_hotplug(int nid); extern int __add_memory(int nid, u64 start, u64 size, mhp_t mhp_flags); extern int add_memory(int nid, u64 start, u64 size, mhp_t mhp_flags); extern int add_memory_resource(int nid, struct resource *resource, diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 322b995942e5..09aafc05aef4 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -609,7 +609,7 @@ struct zone { ZONE_PADDING(_pad1_)

/* free areas of different sizes */

• struct free_area free_area[MAX_ORDER];

• struct free_area *free_area;

  /* zone flags, see below */ unsigned long flags;

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 91ca751ac20c..4ce20b6482aa 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1239,6 +1239,7 @@ static void rollback_node_hotadd(int nid)

arch_refresh_nodedata(nid, NULL); free_percpu(pgdat->per_cpu_nodestats);

• free_area_deinit_core_hotplug(nid); arch_free_nodedata(pgdat); }

diff --git a/mm/page_alloc.c b/mm/page_alloc.c index e4657009fd4f..bfa6962f7615 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -6053,11 +6053,21 @@ void show_free_areas(unsigned int filter, nodemask_t *nodemask)

for_each_populated_zone(zone) { unsigned int order;

• unsigned long nr[MAX_ORDER], flags, total = 0;
  

• unsigned char types[MAX_ORDER];
  

• unsigned long *nr, flags, total = 0;
  

• unsigned char *types;
  
  

  if (show_mem_node_skip(filter, zone_to_nid(zone), nodemask)) continue;

• nr = kmalloc(sizeof(unsigned long) * MAX_ORDER, GFP_KERNEL);
  

• if (!nr)
  

• 	goto skip_zone;
  

• types = kmalloc(sizeof(unsigned char) * MAX_ORDER, GFP_KERNEL);
  

• if (!types) {
  

• 	kfree(nr);
  

• 	goto skip_zone;
  

• }
  

• show_node(zone); printk(KERN_CONT "%s: ", zone->name);

@@ -6083,8 +6093,11 @@ void show_free_areas(unsigned int filter, nodemask_t *nodemask) show_migration_types(types[order]); } printk(KERN_CONT "= %lukB\n", K(total));

• }

• kfree(nr);
  

• kfree(types);
  

• }

+skip_zone: hugetlb_show_meminfo();

printk("%ld total pagecache pages\n", global_node_page_state(NR_FILE_PAGES)); @@ -7429,8 +7442,8 @@ static void __meminit pgdat_init_internals(struct pglist_data *pgdat) lruvec_init(&pgdat->__lruvec); }

-static void __meminit zone_init_internals(struct zone *zone, enum zone_type idx, int nid,

• 					unsigned long remaining_pages)
  

+static void __init zone_init_internals(struct zone *zone, enum zone_type idx, int nid,

• 					unsigned long remaining_pages, bool hotplug)
  

  { atomic_long_set(&zone->managed_pages, remaining_pages); zone_set_nid(zone, nid);

@@ -7439,6 +7452,16 @@ static void __meminit zone_init_internals(struct zone *zone, enum zone_type idx, spin_lock_init(&zone->lock); zone_seqlock_init(zone); zone_pcp_init(zone);

• if (hotplug)

• zone->free_area =
  

• 	kzalloc_node(sizeof(struct free_area) * MAX_ORDER,
  

• 		     GFP_KERNEL, nid);
  

• else

• zone->free_area =
  

• 	memblock_alloc_node(sizeof(struct free_area) * MAX_ORDER,
  

• 			    sizeof(struct free_area), nid);
  

• BUG_ON(!zone->free_area);

• }

  /*

@@ -7456,7 +7479,18 @@ void __ref free_area_init_core_hotplug(int nid)

pgdat_init_internals(pgdat); for (z = 0; z < MAX_NR_ZONES; z++)

• zone_init_internals(&pgdat->node_zones[z], z, nid, 0);
  

• zone_init_internals(&pgdat->node_zones[z], z, nid, 0, true);
  

+}

+void __ref free_area_deinit_core_hotplug(int nid) +{

• enum zone_type z;
• pg_data_t *pgdat = NODE_DATA(nid);
• for (z = 0; z < MAX_NR_ZONES; z++) {

• kfree(pgdat->node_zones[z].free_area);
  

• pgdat->node_zones[z].free_area = NULL;
  

• } } #endif

@@ -7519,7 +7553,7 @@ static void __init free_area_init_core(struct pglist_data *pgdat) * when the bootmem allocator frees pages into the buddy system. * And all highmem pages will be managed by the buddy system. */

• zone_init_internals(zone, j, nid, freesize);
  

• zone_init_internals(zone, j, nid, freesize, false);
  
  

  if (!size) continue;