| Message ID | 1596191874-27757-1-git-send-email-lirongqing@baidu.com |
|---|---|
| State | Awaiting Upstream |
| Delegated to: | David Miller |
| Headers | show |
| Series | [v2] i40e: optimise prefetch page refcount | expand |
> -----Original Message----- > From: Li RongQing <lirongqing@baidu.com> > Sent: Friday, July 31, 2020 3:38 AM > To: netdev@vger.kernel.org; intel-wired-lan@lists.osuosl.org; > kuba@kernel.org; Bowers, AndrewX <andrewx.bowers@intel.com>; > Nguyen, Anthony L <anthony.l.nguyen@intel.com> > Subject: [PATCH][v2] i40e: optimise prefetch page refcount > > refcount of rx_buffer page will be added here originally, so prefetchw is > needed, but after commit 1793668c3b8c ("i40e/i40evf: Update code to > better handle incrementing page count"), and refcount is not added > everytime, so change prefetchw as prefetch, > > now it mainly services page_address(), but which accesses struct page only > when WANT_PAGE_VIRTUAL or HASHED_PAGE_VIRTUAL is defined > otherwise it returns address based on offset, so we prefetch it conditionally > > Jakub suggested to define prefetch_page_address in a common header > > Suggested-by: Jakub Kicinski <kuba@kernel.org> > Signed-off-by: Li RongQing <lirongqing@baidu.com> > --- > diff with v1: create a common function prefetch_page_address > > drivers/net/ethernet/intel/i40e/i40e_txrx.c | 2 +- > include/linux/prefetch.h | 7 +++++++ > 2 files changed, 8 insertions(+), 1 deletion(-) Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
> From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf Of Li > RongQing > Sent: Friday, July 31, 2020 3:38 AM > To: netdev@vger.kernel.org; intel-wired-lan@lists.osuosl.org; > kuba@kernel.org; Bowers, AndrewX <andrewx.bowers@intel.com>; > Nguyen, Anthony L <anthony.l.nguyen@intel.com> > Subject: [Intel-wired-lan] [PATCH][v2] i40e: optimise prefetch page refcount > > refcount of rx_buffer page will be added here originally, so prefetchw > is needed, but after commit 1793668c3b8c ("i40e/i40evf: Update code to > better handle incrementing page count"), and refcount is not added > everytime, so change prefetchw as prefetch, > > now it mainly services page_address(), but which accesses struct page > only when WANT_PAGE_VIRTUAL or HASHED_PAGE_VIRTUAL is defined > otherwise > it returns address based on offset, so we prefetch it conditionally > > Jakub suggested to define prefetch_page_address in a common header > > Suggested-by: Jakub Kicinski <kuba@kernel.org> > Signed-off-by: Li RongQing <lirongqing@baidu.com> > --- > diff with v1: create a common function prefetch_page_address > > drivers/net/ethernet/intel/i40e/i40e_txrx.c | 2 +- > include/linux/prefetch.h | 7 +++++++ > 2 files changed, 8 insertions(+), 1 deletion(-) Tested-by: Aaron Brown <aaron.f.brown@intel.com>
diff with v1: create a common function prefetch_page_address drivers/net/ethernet/intel/i40e/i40e_txrx.c | 2 +- include/linux/prefetch.h | 7 +++++++ 2 files changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c index 62f5b2d35f63..5f9fe55bb66d 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c +++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c @@ -1953,7 +1953,7 @@ static struct i40e_rx_buffer *i40e_get_rx_buffer(struct i40e_ring *rx_ring, struct i40e_rx_buffer *rx_buffer; rx_buffer = i40e_rx_bi(rx_ring, rx_ring->next_to_clean); - prefetchw(rx_buffer->page); + prefetch_page_address(rx_buffer->page); /* we are reusing so sync this buffer for CPU use */ dma_sync_single_range_for_cpu(rx_ring->dev, diff --git a/include/linux/prefetch.h b/include/linux/prefetch.h index 13eafebf3549..1e0283982dd3 100644 --- a/include/linux/prefetch.h +++ b/include/linux/prefetch.h @@ -62,4 +62,11 @@ static inline void prefetch_range(void *addr, size_t len) #endif } +static inline void prefetch_page_address(struct page *page) +{ +#if defined(WANT_PAGE_VIRTUAL) || defined(HASHED_PAGE_VIRTUAL) + prefetch(page); +#endif +} + #endif
refcount of rx_buffer page will be added here originally, so prefetchw is needed, but after commit 1793668c3b8c ("i40e/i40evf: Update code to better handle incrementing page count"), and refcount is not added everytime, so change prefetchw as prefetch, now it mainly services page_address(), but which accesses struct page only when WANT_PAGE_VIRTUAL or HASHED_PAGE_VIRTUAL is defined otherwise it returns address based on offset, so we prefetch it conditionally Jakub suggested to define prefetch_page_address in a common header Suggested-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Li RongQing <lirongqing@baidu.com> ---