[RFC PATCH 13/15] mm: convert MAX_ORDER sized static arrays to dynamic ones.
Christian König
christian.koenig at amd.com
Thu Aug 5 19:16:25 UTC 2021
Am 05.08.21 um 21:02 schrieb Zi Yan:
> From: Zi Yan <ziy at 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 at nvidia.com>
> Cc: Dave Young <dyoung at redhat.com>
> Cc: Jonathan Corbet <corbet at lwn.net>
> Cc: Christian Koenig <christian.koenig at amd.com>
> Cc: David Airlie <airlied at linux.ie>
> Cc: kexec at lists.infradead.org
> Cc: linux-doc at vger.kernel.org
> Cc: dri-devel at lists.freedesktop.org
> Cc: linux-mm at kvack.org
> Cc: linux-kernel at 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;
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