> @@ -280,14 +268,14 @@ void dma_pool_destroy(struct dma_pool *pool) > mutex_unlock(&pools_reg_lock); > > list_for_each_entry_safe(page, tmp, &pool->page_list, page_list) { > + if (!is_page_busy(page)) > + dma_free_coherent(pool->dev, pool->allocation, > + page->vaddr, page->dma); > + else > dev_err(pool->dev, "%s %s, %p busy\n", __func__, > pool->name, page->vaddr); > + list_del(&page->page_list); > + kfree(page); Hmm. The is_page_busy case is really a should not happen case. What is the benefit of skipping the dma_free_coherent and leaking memory here, vs letting KASAN and friends see the free and possibly help with debugging? In other words, why is this not: WARN_ON_ONCE(is_page_busy(page)); dma_free_coherent(pool->dev, pool->allocation, page->vaddr, page->dma); ... > page->in_use--; > *(int *)vaddr = page->offset; > page->offset = offset; > - /* > - * Resist a temptation to do > - * if (!is_page_busy(page)) pool_free_page(pool, page); > - * Better have a few empty pages hang around. > - */ This doesn't look related to the rest, or am I missing something?