Re: [RFC PATCH 13/15] mm: convert MAX_ORDER sized static arrays to dynamic ones.
From: Christian König
Date: Thu Aug 05 2021 - 15:16:42 EST
Am 05.08.21 um 21:02 schrieb Zi Yan:
From: Zi Yan <ziy@xxxxxxxxxx>
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@xxxxxxxxxx>
Cc: Dave Young <dyoung@xxxxxxxxxx>
Cc: Jonathan Corbet <corbet@xxxxxxx>
Cc: Christian Koenig <christian.koenig@xxxxxxx>
Cc: David Airlie <airlied@xxxxxxxx>
Cc: kexec@xxxxxxxxxxxxxxxxxxx
Cc: linux-doc@xxxxxxxxxxxxxxx
Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
Cc: linux-mm@xxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
---
.../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;