Re: [PATCH 4/4] dmapool: Improve memory usage for devices which can'tcross boundaries

From: roel
Date: Wed Sep 26 2007 - 16:12:43 EST


Matthew Wilcox wrote:

[...]

> @@ -142,14 +144,13 @@ struct dma_pool *dma_pool_create(const char *name, struct device *dev,
> if ((size % align) != 0)
> size = ALIGN(size, align);
>
> - if (allocation == 0) {
> - if (PAGE_SIZE < size)
> - allocation = size;
> - else
> - allocation = PAGE_SIZE;
> - // FIXME: round up for less fragmentation
> - } else if (allocation < size)
> + allocation = max_t(size_t, size, PAGE_SIZE);
> +
> + if (!boundary) {
> + boundary = allocation;
> + } else if ((boundary < size) || (boundary & (boundary - 1))) {
> return NULL;
> + }

if (!boundary)
boundary = allocation;
else if (boundary < size || boundary & (boundary - 1))
return NULL;

[...]

> @@ -190,11 +192,14 @@ struct dma_pool *dma_pool_create(const char *name, struct device *dev,
> static void pool_initialise_page(struct dma_pool *pool, struct dma_page *page)
> {
> unsigned int offset = 0;
> + unsigned int next_boundary = pool->boundary;
>
> do {
> unsigned int next = offset + pool->size;
> - if (unlikely((next + pool->size) >= pool->allocation))
> - next = pool->allocation;
> + if (unlikely((next + pool->size) >= next_boundary)) {

if (unlikely(next + pool->size >= next_boundary)) {

[...]
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/