Re: [PATCH net-next v5 2/2] page_pool: Track DMA-mapped pages and unmap them when destroying the pool

Paolo Abeni
2025-04-01T08:52:22Z

On 3/28/25 1:19 PM, Toke Høiland-Jørgensen wrote:
> @@ -463,13 +462,21 @@ page_pool_dma_sync_for_device(const struct page_pool *pool,
> netmem_ref netmem,
> u32 dma_sync_size)
> {
> - if (pool->dma_sync && dma_dev_need_sync(pool->p.dev))
> - __page_pool_dma_sync_for_device(pool, netmem, dma_sync_size);
> + if (pool->dma_sync && dma_dev_need_sync(pool->p.dev)) {

Lacking a READ_ONCE() here, I think it's within compiler's right do some
unexpected optimization between this read and the next one. Also it will
make the double read more explicit.

Thanks,

Paolo