Messages in this thread | | | From | Haiyang Zhang <> | Subject | RE: [PATCH V3,net-next, 2/4] net: mana: Refactor RX buffer allocation code to prepare for various MTU | Date | Thu, 13 Apr 2023 14:03:50 +0000 |
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> -----Original Message----- > From: Leon Romanovsky <leon@kernel.org> > Sent: Thursday, April 13, 2023 9:04 AM > To: Haiyang Zhang <haiyangz@microsoft.com> > Cc: linux-hyperv@vger.kernel.org; netdev@vger.kernel.org; Dexuan Cui > <decui@microsoft.com>; KY Srinivasan <kys@microsoft.com>; Paul Rosswurm > <paulros@microsoft.com>; olaf@aepfle.de; vkuznets@redhat.com; > davem@davemloft.net; wei.liu@kernel.org; edumazet@google.com; > kuba@kernel.org; pabeni@redhat.com; Long Li <longli@microsoft.com>; > ssengar@linux.microsoft.com; linux-rdma@vger.kernel.org; > daniel@iogearbox.net; john.fastabend@gmail.com; bpf@vger.kernel.org; > ast@kernel.org; Ajay Sharma <sharmaajay@microsoft.com>; > hawk@kernel.org; linux-kernel@vger.kernel.org > Subject: Re: [PATCH V3,net-next, 2/4] net: mana: Refactor RX buffer allocation > code to prepare for various MTU > > On Wed, Apr 12, 2023 at 02:16:01PM -0700, Haiyang Zhang wrote: > > Move out common buffer allocation code from mana_process_rx_cqe() and > > mana_alloc_rx_wqe() to helper functions. > > Refactor related variables so they can be changed in one place, and buffer > > sizes are in sync. > > > > Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com> > > Reviewed-by: Jesse Brandeburg <jesse.brandeburg@intel.com> > > --- > > V3: > > Refectored to multiple patches for readability. Suggested by Jacob Keller. > > > > V2: > > Refectored to multiple patches for readability. Suggested by Yunsheng Lin. > > > > --- > > drivers/net/ethernet/microsoft/mana/mana_en.c | 154 ++++++++++------- > - > > include/net/mana/mana.h | 6 +- > > 2 files changed, 91 insertions(+), 69 deletions(-) > > <...> > > > +static void *mana_get_rxfrag(struct mana_rxq *rxq, struct device *dev, > > + dma_addr_t *da, bool is_napi) > > +{ > > + struct page *page; > > + void *va; > > + > > + /* Reuse XDP dropped page if available */ > > + if (rxq->xdp_save_va) { > > + va = rxq->xdp_save_va; > > + rxq->xdp_save_va = NULL; > > + } else { > > + page = dev_alloc_page(); > > Documentation/networking/page_pool.rst > 10 Basic use involves replacing alloc_pages() calls with the > 11 page_pool_alloc_pages() call. Drivers should use > page_pool_dev_alloc_pages() > 12 replacing dev_alloc_pages(). > > General question, is this sentence applicable to all new code or only > for XDP related paths?
Quote from the context before that sentence --
============= Page Pool API ============= The page_pool allocator is optimized for the XDP mode that uses one frame per-page, but it can fallback on the regular page allocator APIs. Basic use involves replacing alloc_pages() calls with the page_pool_alloc_pages() call. Drivers should use page_pool_dev_alloc_pages() replacing dev_alloc_pages().
--unquote
So the page pool is optimized for the XDP, and that sentence is applicable to drivers that have set up page pool for XDP optimization. static inline struct page *page_pool_dev_alloc_pages(struct page_pool *pool) //need a pool been set up
Back to our mana driver, we don't have page pool setup yet. (will consider in the future) So we cannot call page_pool_dev_alloc_pages(pool) in this place yet.
Thanks, - Haiyang
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