Re: [PATCH 2/2] staging: android: ion: Combine cache and uncache pools

From: Sumit Semwal
Date: Wed Feb 07 2018 - 09:34:26 EST


Hello Yisheng,

On 7 February 2018 at 09:29, Yisheng Xie <xieyisheng1@xxxxxxxxxx> wrote:
> Now we call dma_map in the dma_buf API callbacks and handle explicit
> caching by the dma_buf sync API, which make cache and uncache pools
> in the same handling flow, which can be combined.
>
Thanks for the patch! Perhaps you should also put the version history
here, to capture the changes from previous versions?

> Signed-off-by: Yisheng Xie <xieyisheng1@xxxxxxxxxx>
With that done, please feel free to add
Acked-by: Sumit Semwal <sumit.semwal@xxxxxxxxxx>

> ---
> drivers/staging/android/ion/ion.c | 5 --
> drivers/staging/android/ion/ion.h | 13 +----
> drivers/staging/android/ion/ion_page_pool.c | 5 +-
> drivers/staging/android/ion/ion_system_heap.c | 76 +++++----------------------
> 4 files changed, 16 insertions(+), 83 deletions(-)
>
> diff --git a/drivers/staging/android/ion/ion.c b/drivers/staging/android/ion/ion.c
> index 461b193..c094be2 100644
> --- a/drivers/staging/android/ion/ion.c
> +++ b/drivers/staging/android/ion/ion.c
> @@ -33,11 +33,6 @@
> static struct ion_device *internal_dev;
> static int heap_id;
>
> -bool ion_buffer_cached(struct ion_buffer *buffer)
> -{
> - return !!(buffer->flags & ION_FLAG_CACHED);
> -}
> -
> /* this function should only be called while dev->lock is held */
> static void ion_buffer_add(struct ion_device *dev,
> struct ion_buffer *buffer)
> diff --git a/drivers/staging/android/ion/ion.h b/drivers/staging/android/ion/ion.h
> index 1bc443f..ea08978 100644
> --- a/drivers/staging/android/ion/ion.h
> +++ b/drivers/staging/android/ion/ion.h
> @@ -185,14 +185,6 @@ struct ion_heap {
> };
>
> /**
> - * ion_buffer_cached - this ion buffer is cached
> - * @buffer: buffer
> - *
> - * indicates whether this ion buffer is cached
> - */
> -bool ion_buffer_cached(struct ion_buffer *buffer);
> -
> -/**
> * ion_device_add_heap - adds a heap to the ion device
> * @heap: the heap to add
> */
> @@ -302,7 +294,6 @@ size_t ion_heap_freelist_shrink(struct ion_heap *heap,
> * @gfp_mask: gfp_mask to use from alloc
> * @order: order of pages in the pool
> * @list: plist node for list of pools
> - * @cached: it's cached pool or not
> *
> * Allows you to keep a pool of pre allocated pages to use from your heap.
> * Keeping a pool of pages that is ready for dma, ie any cached mapping have
> @@ -312,7 +303,6 @@ size_t ion_heap_freelist_shrink(struct ion_heap *heap,
> struct ion_page_pool {
> int high_count;
> int low_count;
> - bool cached;
> struct list_head high_items;
> struct list_head low_items;
> struct mutex mutex;
> @@ -321,8 +311,7 @@ struct ion_page_pool {
> struct plist_node list;
> };
>
> -struct ion_page_pool *ion_page_pool_create(gfp_t gfp_mask, unsigned int order,
> - bool cached);
> +struct ion_page_pool *ion_page_pool_create(gfp_t gfp_mask, unsigned int order);
> void ion_page_pool_destroy(struct ion_page_pool *pool);
> struct page *ion_page_pool_alloc(struct ion_page_pool *pool);
> void ion_page_pool_free(struct ion_page_pool *pool, struct page *page);
> diff --git a/drivers/staging/android/ion/ion_page_pool.c b/drivers/staging/android/ion/ion_page_pool.c
> index 6d2caf0..db8f614 100644
> --- a/drivers/staging/android/ion/ion_page_pool.c
> +++ b/drivers/staging/android/ion/ion_page_pool.c
> @@ -123,8 +123,7 @@ int ion_page_pool_shrink(struct ion_page_pool *pool, gfp_t gfp_mask,
> return freed;
> }
>
> -struct ion_page_pool *ion_page_pool_create(gfp_t gfp_mask, unsigned int order,
> - bool cached)
> +struct ion_page_pool *ion_page_pool_create(gfp_t gfp_mask, unsigned int order)
> {
> struct ion_page_pool *pool = kmalloc(sizeof(*pool), GFP_KERNEL);
>
> @@ -138,8 +137,6 @@ struct ion_page_pool *ion_page_pool_create(gfp_t gfp_mask, unsigned int order,
> pool->order = order;
> mutex_init(&pool->mutex);
> plist_node_init(&pool->list, order);
> - if (cached)
> - pool->cached = true;
>
> return pool;
> }
> diff --git a/drivers/staging/android/ion/ion_system_heap.c b/drivers/staging/android/ion/ion_system_heap.c
> index bc19cdd..701eb9f 100644
> --- a/drivers/staging/android/ion/ion_system_heap.c
> +++ b/drivers/staging/android/ion/ion_system_heap.c
> @@ -41,31 +41,16 @@ static inline unsigned int order_to_size(int order)
>
> struct ion_system_heap {
> struct ion_heap heap;
> - struct ion_page_pool *uncached_pools[NUM_ORDERS];
> - struct ion_page_pool *cached_pools[NUM_ORDERS];
> + struct ion_page_pool *pools[NUM_ORDERS];
> };
>
> -/**
> - * The page from page-pool are all zeroed before. We need do cache
> - * clean for cached buffer. The uncached buffer are always non-cached
> - * since it's allocated. So no need for non-cached pages.
> - */
> static struct page *alloc_buffer_page(struct ion_system_heap *heap,
> struct ion_buffer *buffer,
> unsigned long order)
> {
> - bool cached = ion_buffer_cached(buffer);
> - struct ion_page_pool *pool;
> - struct page *page;
> + struct ion_page_pool *pool = heap->pools[order_to_index(order)];
>
> - if (!cached)
> - pool = heap->uncached_pools[order_to_index(order)];
> - else
> - pool = heap->cached_pools[order_to_index(order)];
> -
> - page = ion_page_pool_alloc(pool);
> -
> - return page;
> + return ion_page_pool_alloc(pool);
> }
>
> static void free_buffer_page(struct ion_system_heap *heap,
> @@ -73,7 +58,6 @@ static void free_buffer_page(struct ion_system_heap *heap,
> {
> struct ion_page_pool *pool;
> unsigned int order = compound_order(page);
> - bool cached = ion_buffer_cached(buffer);
>
> /* go to system */
> if (buffer->private_flags & ION_PRIV_FLAG_SHRINKER_FREE) {
> @@ -81,10 +65,7 @@ static void free_buffer_page(struct ion_system_heap *heap,
> return;
> }
>
> - if (!cached)
> - pool = heap->uncached_pools[order_to_index(order)];
> - else
> - pool = heap->cached_pools[order_to_index(order)];
> + pool = heap->pools[order_to_index(order)];
>
> ion_page_pool_free(pool, page);
> }
> @@ -190,8 +171,7 @@ static void ion_system_heap_free(struct ion_buffer *buffer)
> static int ion_system_heap_shrink(struct ion_heap *heap, gfp_t gfp_mask,
> int nr_to_scan)
> {
> - struct ion_page_pool *uncached_pool;
> - struct ion_page_pool *cached_pool;
> + struct ion_page_pool *pool;
> struct ion_system_heap *sys_heap;
> int nr_total = 0;
> int i, nr_freed;
> @@ -203,26 +183,15 @@ static int ion_system_heap_shrink(struct ion_heap *heap, gfp_t gfp_mask,
> only_scan = 1;
>
> for (i = 0; i < NUM_ORDERS; i++) {
> - uncached_pool = sys_heap->uncached_pools[i];
> - cached_pool = sys_heap->cached_pools[i];
> + pool = sys_heap->pools[i];
>
> if (only_scan) {
> - nr_total += ion_page_pool_shrink(uncached_pool,
> + nr_total += ion_page_pool_shrink(pool,
> gfp_mask,
> nr_to_scan);
>
> - nr_total += ion_page_pool_shrink(cached_pool,
> - gfp_mask,
> - nr_to_scan);
> } else {
> - nr_freed = ion_page_pool_shrink(uncached_pool,
> - gfp_mask,
> - nr_to_scan);
> - nr_to_scan -= nr_freed;
> - nr_total += nr_freed;
> - if (nr_to_scan <= 0)
> - break;
> - nr_freed = ion_page_pool_shrink(cached_pool,
> + nr_freed = ion_page_pool_shrink(pool,
> gfp_mask,
> nr_to_scan);
> nr_to_scan -= nr_freed;
> @@ -253,26 +222,16 @@ static int ion_system_heap_debug_show(struct ion_heap *heap, struct seq_file *s,
> struct ion_page_pool *pool;
>
> for (i = 0; i < NUM_ORDERS; i++) {
> - pool = sys_heap->uncached_pools[i];
> + pool = sys_heap->pools[i];
>
> - seq_printf(s, "%d order %u highmem pages uncached %lu total\n",
> + seq_printf(s, "%d order %u highmem pages %lu total\n",
> pool->high_count, pool->order,
> (PAGE_SIZE << pool->order) * pool->high_count);
> - seq_printf(s, "%d order %u lowmem pages uncached %lu total\n",
> + seq_printf(s, "%d order %u lowmem pages %lu total\n",
> pool->low_count, pool->order,
> (PAGE_SIZE << pool->order) * pool->low_count);
> }
>
> - for (i = 0; i < NUM_ORDERS; i++) {
> - pool = sys_heap->cached_pools[i];
> -
> - seq_printf(s, "%d order %u highmem pages cached %lu total\n",
> - pool->high_count, pool->order,
> - (PAGE_SIZE << pool->order) * pool->high_count);
> - seq_printf(s, "%d order %u lowmem pages cached %lu total\n",
> - pool->low_count, pool->order,
> - (PAGE_SIZE << pool->order) * pool->low_count);
> - }
> return 0;
> }
>
> @@ -285,8 +244,7 @@ static void ion_system_heap_destroy_pools(struct ion_page_pool **pools)
> ion_page_pool_destroy(pools[i]);
> }
>
> -static int ion_system_heap_create_pools(struct ion_page_pool **pools,
> - bool cached)
> +static int ion_system_heap_create_pools(struct ion_page_pool **pools)
> {
> int i;
> gfp_t gfp_flags = low_order_gfp_flags;
> @@ -297,7 +255,7 @@ static int ion_system_heap_create_pools(struct ion_page_pool **pools,
> if (orders[i] > 4)
> gfp_flags = high_order_gfp_flags;
>
> - pool = ion_page_pool_create(gfp_flags, orders[i], cached);
> + pool = ion_page_pool_create(gfp_flags, orders[i]);
> if (!pool)
> goto err_create_pool;
> pools[i] = pool;
> @@ -320,18 +278,12 @@ static struct ion_heap *__ion_system_heap_create(void)
> heap->heap.type = ION_HEAP_TYPE_SYSTEM;
> heap->heap.flags = ION_HEAP_FLAG_DEFER_FREE;
>
> - if (ion_system_heap_create_pools(heap->uncached_pools, false))
> + if (ion_system_heap_create_pools(heap->pools))
> goto free_heap;
>
> - if (ion_system_heap_create_pools(heap->cached_pools, true))
> - goto destroy_uncached_pools;
> -
> heap->heap.debug_show = ion_system_heap_debug_show;
> return &heap->heap;
>
> -destroy_uncached_pools:
> - ion_system_heap_destroy_pools(heap->uncached_pools);
> -
> free_heap:
> kfree(heap);
> return ERR_PTR(-ENOMEM);
> --
> 1.7.12.4
>



--
Thanks and regards,

Sumit Semwal
Linaro Mobile Group - Kernel Team Lead
Linaro.org â Open source software for ARM SoCs