| Message ID | 1629425195-10130-3-git-send-email-linyunsheng@huawei.com |
|---|---|
| State | New |
| Headers | show |
| Series | Some minor optimization for page pool | expand |
On 20.08.2021 04:06, Yunsheng Lin wrote: > If the DMA_ATTR_SKIP_CPU_SYNC is not set, cpu syncing is > also done in dma_map_page_attrs(), so set the attrs according > to pool->p.flags to avoid calling dma sync function again. > > Also mark the dma error as the unlikely case While we are at > it. > This shouldn't be needed. dma_mapping_error() will be (most likely) inlined by the compiler, and it includes the unlikely() hint. > Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com> > --- > net/core/page_pool.c | 11 ++++++----- > 1 file changed, 6 insertions(+), 5 deletions(-) > > diff --git a/net/core/page_pool.c b/net/core/page_pool.c > index 1a69784..8172045 100644 > --- a/net/core/page_pool.c > +++ b/net/core/page_pool.c > @@ -191,8 +191,12 @@ static void page_pool_dma_sync_for_device(struct page_pool *pool, > > static bool page_pool_dma_map(struct page_pool *pool, struct page *page) > { > + unsigned long attrs = DMA_ATTR_SKIP_CPU_SYNC; > dma_addr_t dma; > > + if (pool->p.flags & PP_FLAG_DMA_SYNC_DEV) > + attrs = 0; > + > /* Setup DMA mapping: use 'struct page' area for storing DMA-addr > * since dma_addr_t can be either 32 or 64 bits and does not always fit > * into page private data (i.e 32bit cpu with 64bit DMA caps) > @@ -200,15 +204,12 @@ static bool page_pool_dma_map(struct page_pool *pool, struct page *page) > */ > dma = dma_map_page_attrs(pool->p.dev, page, 0, > (PAGE_SIZE << pool->p.order), > - pool->p.dma_dir, DMA_ATTR_SKIP_CPU_SYNC); > - if (dma_mapping_error(pool->p.dev, dma)) > + pool->p.dma_dir, attrs); > + if (unlikely(dma_mapping_error(pool->p.dev, dma))) > return false; > > page_pool_set_dma_addr(page, dma); > > - if (pool->p.flags & PP_FLAG_DMA_SYNC_DEV) > - page_pool_dma_sync_for_device(pool, page, pool->p.max_len); > - > return true; > } > >
diff --git a/net/core/page_pool.c b/net/core/page_pool.c index 1a69784..8172045 100644 --- a/net/core/page_pool.c +++ b/net/core/page_pool.c @@ -191,8 +191,12 @@ static void page_pool_dma_sync_for_device(struct page_pool *pool, static bool page_pool_dma_map(struct page_pool *pool, struct page *page) { + unsigned long attrs = DMA_ATTR_SKIP_CPU_SYNC; dma_addr_t dma; + if (pool->p.flags & PP_FLAG_DMA_SYNC_DEV) + attrs = 0; + /* Setup DMA mapping: use 'struct page' area for storing DMA-addr * since dma_addr_t can be either 32 or 64 bits and does not always fit * into page private data (i.e 32bit cpu with 64bit DMA caps) @@ -200,15 +204,12 @@ static bool page_pool_dma_map(struct page_pool *pool, struct page *page) */ dma = dma_map_page_attrs(pool->p.dev, page, 0, (PAGE_SIZE << pool->p.order), - pool->p.dma_dir, DMA_ATTR_SKIP_CPU_SYNC); - if (dma_mapping_error(pool->p.dev, dma)) + pool->p.dma_dir, attrs); + if (unlikely(dma_mapping_error(pool->p.dev, dma))) return false; page_pool_set_dma_addr(page, dma); - if (pool->p.flags & PP_FLAG_DMA_SYNC_DEV) - page_pool_dma_sync_for_device(pool, page, pool->p.max_len); - return true; }
If the DMA_ATTR_SKIP_CPU_SYNC is not set, cpu syncing is also done in dma_map_page_attrs(), so set the attrs according to pool->p.flags to avoid calling dma sync function again. Also mark the dma error as the unlikely case While we are at it. Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com> --- net/core/page_pool.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-)