The code to figure out how many pages to shrink the pool ends up capping the 'count' at _manager->options.max_size - which is OK. Except that the 'count' is also used when accounting for how many pages are recycled - which we end up with the invalid values. This fixes it by using a different value for the amount of pages to shrink.
On top of that we would free the cached page pool - which is nonsense as they are deleted from the pool - so there are no free pages in that pool..
Also we also missed the opportunity to batch the amount of pages to free (similar to how ttm_page_alloc.c does it). This reintroduces the code that was lost during rebasing.
Reviewed-by: Jerome Glisse jglisse@redhat.com Signed-off-by: Konrad Rzeszutek Wilk konrad.wilk@oracle.com --- drivers/gpu/drm/ttm/ttm_page_alloc_dma.c | 15 ++++++++++----- 1 files changed, 10 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c b/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c index 6c06d0b..156ddcd 100644 --- a/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c +++ b/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c @@ -949,7 +949,7 @@ void ttm_dma_unpopulate(struct ttm_dma_tt *ttm_dma, struct device *dev) struct dma_page *d_page, *next; enum pool_type type; bool is_cached = false; - unsigned count = 0, i; + unsigned count = 0, i, npages = 0; unsigned long irq_flags;
type = ttm_to_type(ttm->page_flags, ttm->caching_state); @@ -974,8 +974,13 @@ void ttm_dma_unpopulate(struct ttm_dma_tt *ttm_dma, struct device *dev) } else { pool->npages_free += count; list_splice(&ttm_dma->pages_list, &pool->free_list); + npages = count; if (pool->npages_free > _manager->options.max_size) { - count = pool->npages_free - _manager->options.max_size; + npages = pool->npages_free - _manager->options.max_size; + /* free at least NUM_PAGES_TO_ALLOC number of pages + * to reduce calls to set_memory_wb */ + if (npages < NUM_PAGES_TO_ALLOC) + npages = NUM_PAGES_TO_ALLOC; } } spin_unlock_irqrestore(&pool->lock, irq_flags); @@ -999,9 +1004,9 @@ void ttm_dma_unpopulate(struct ttm_dma_tt *ttm_dma, struct device *dev) ttm_dma->dma_address[i] = 0; }
- /* shrink pool if necessary */ - if (count) - ttm_dma_page_pool_free(pool, count); + /* shrink pool if necessary (only on !is_cached pools)*/ + if (npages) + ttm_dma_page_pool_free(pool, npages); ttm->state = tt_unpopulated; } EXPORT_SYMBOL_GPL(ttm_dma_unpopulate);