* [PATCH net-next 0/2] Some minor optimization for page pool @ 2021-08-20 2:06 Yunsheng Lin 2021-08-20 2:06 ` [PATCH net-next 1/2] page_pool: use relexed atomic for release side accounting Yunsheng Lin 2021-08-20 2:06 ` [PATCH net-next 2/2] page_pool: optimize the cpu sync operation when DMA mapping Yunsheng Lin 0 siblings, 2 replies; 5+ messages in thread From: Yunsheng Lin @ 2021-08-20 2:06 UTC (permalink / raw) To: davem, kuba; +Cc: hawk, ilias.apalodimas, netdev, linux-kernel Patch 1: Use relexed atomic for release side accounting Patch 2: Minor optimize for page_pool_dma_map() function Yunsheng Lin (2): page_pool: use relexed atomic for release side accounting page_pool: optimize the cpu sync operation when DMA mapping net/core/page_pool.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) -- 2.7.4 ^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH net-next 1/2] page_pool: use relexed atomic for release side accounting 2021-08-20 2:06 [PATCH net-next 0/2] Some minor optimization for page pool Yunsheng Lin @ 2021-08-20 2:06 ` Yunsheng Lin 2021-08-20 2:06 ` [PATCH net-next 2/2] page_pool: optimize the cpu sync operation when DMA mapping Yunsheng Lin 1 sibling, 0 replies; 5+ messages in thread From: Yunsheng Lin @ 2021-08-20 2:06 UTC (permalink / raw) To: davem, kuba; +Cc: hawk, ilias.apalodimas, netdev, linux-kernel There is no need to synchronize the account updating, so use the relexed atomic to avoid some memory barrier in the data path. Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com> --- net/core/page_pool.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/core/page_pool.c b/net/core/page_pool.c index e140905..1a69784 100644 --- a/net/core/page_pool.c +++ b/net/core/page_pool.c @@ -370,7 +370,7 @@ void page_pool_release_page(struct page_pool *pool, struct page *page) /* This may be the last page returned, releasing the pool, so * it is not safe to reference pool afterwards. */ - count = atomic_inc_return(&pool->pages_state_release_cnt); + count = atomic_inc_return_relaxed(&pool->pages_state_release_cnt); trace_page_pool_state_release(pool, page, count); } EXPORT_SYMBOL(page_pool_release_page); -- 2.7.4 ^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH net-next 2/2] page_pool: optimize the cpu sync operation when DMA mapping 2021-08-20 2:06 [PATCH net-next 0/2] Some minor optimization for page pool Yunsheng Lin 2021-08-20 2:06 ` [PATCH net-next 1/2] page_pool: use relexed atomic for release side accounting Yunsheng Lin @ 2021-08-20 2:06 ` Yunsheng Lin 2021-08-20 6:10 ` Heiner Kallweit 1 sibling, 1 reply; 5+ messages in thread From: Yunsheng Lin @ 2021-08-20 2:06 UTC (permalink / raw) To: davem, kuba; +Cc: hawk, ilias.apalodimas, netdev, linux-kernel 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(-) 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; } -- 2.7.4 ^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH net-next 2/2] page_pool: optimize the cpu sync operation when DMA mapping 2021-08-20 2:06 ` [PATCH net-next 2/2] page_pool: optimize the cpu sync operation when DMA mapping Yunsheng Lin @ 2021-08-20 6:10 ` Heiner Kallweit 2021-08-20 6:29 ` Yunsheng Lin 0 siblings, 1 reply; 5+ messages in thread From: Heiner Kallweit @ 2021-08-20 6:10 UTC (permalink / raw) To: Yunsheng Lin, davem, kuba; +Cc: hawk, ilias.apalodimas, netdev, linux-kernel 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; > } > > ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH net-next 2/2] page_pool: optimize the cpu sync operation when DMA mapping 2021-08-20 6:10 ` Heiner Kallweit @ 2021-08-20 6:29 ` Yunsheng Lin 0 siblings, 0 replies; 5+ messages in thread From: Yunsheng Lin @ 2021-08-20 6:29 UTC (permalink / raw) To: Heiner Kallweit, davem, kuba; +Cc: hawk, ilias.apalodimas, netdev, linux-kernel On 2021/8/20 14:10, Heiner Kallweit wrote: > 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. Good point, will remove the unlikely() mark. Thanks. > >> 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; >> } >> >> > > . > ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2021-08-20 6:29 UTC | newest] Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2021-08-20 2:06 [PATCH net-next 0/2] Some minor optimization for page pool Yunsheng Lin 2021-08-20 2:06 ` [PATCH net-next 1/2] page_pool: use relexed atomic for release side accounting Yunsheng Lin 2021-08-20 2:06 ` [PATCH net-next 2/2] page_pool: optimize the cpu sync operation when DMA mapping Yunsheng Lin 2021-08-20 6:10 ` Heiner Kallweit 2021-08-20 6:29 ` Yunsheng Lin
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