From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A520A1FB0; Thu, 20 Jul 2023 04:29:41 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1284CC433C7; Thu, 20 Jul 2023 04:29:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1689827381; bh=00793e+DVIX+KzxECbpJoJSmHqRjPxWfvFAIRLmu5OA=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=lGl4yoxCXG41iA0WBnzxDW4JqpYchqiEsKe/VNW6L/qU6UGFO0ogtp3fuAC4r1um7 iYQh1T6+hImHQQNvTaKBU+rDhBSD67g4nEKwJi8l2B2r7u2KvoquSSDlSAP2q0q8Ui A3EfdWFfkVs8HdRr8NxhJfeDc21tt9TQe0Fsg9/UlXEBOyWrMlkaR562Of//eGyWsn Ib5OkPFx65BMxlypb9N0lzKSx+e3ifn8i726AdE/2j7vuVqsdJ1zBOAG8+EHX+PY0T kSmfESVk0CyowibqH1c4ilI1Gnk74Lk1NoKUu/v7hjTvpXsUh7/S5Gv5oT8hHDAG9b 6c3/HW/ju95xA== Date: Wed, 19 Jul 2023 21:29:39 -0700 From: Jakub Kicinski To: Haiyang Zhang Cc: "linux-hyperv@vger.kernel.org" , "netdev@vger.kernel.org" , Dexuan Cui , KY Srinivasan , Paul Rosswurm , "olaf@aepfle.de" , "vkuznets@redhat.com" , "davem@davemloft.net" , "wei.liu@kernel.org" , "edumazet@google.com" , "pabeni@redhat.com" , "leon@kernel.org" , Long Li , "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 , "hawk@kernel.org" , "tglx@linutronix.de" , "shradhagupta@linux.microsoft.com" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH V2,net-next] net: mana: Add page pool for RX buffers Message-ID: <20230719212939.6da38bc0@kernel.org> In-Reply-To: <1689716837-22859-1-git-send-email-haiyangz@microsoft.com> References: <1689716837-22859-1-git-send-email-haiyangz@microsoft.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Tue, 18 Jul 2023 21:48:01 +0000 Haiyang Zhang wrote: > Add page pool for RX buffers for faster buffer cycle and reduce CPU > usage. > > The standard page pool API is used. > @@ -1437,8 +1437,12 @@ static void mana_rx_skb(void *buf_va, struct mana_rxcomp_oob *cqe, > > act = mana_run_xdp(ndev, rxq, &xdp, buf_va, pkt_len); > > - if (act == XDP_REDIRECT && !rxq->xdp_rc) > + if (act == XDP_REDIRECT && !rxq->xdp_rc) { > + if (from_pool) > + page_pool_release_page(rxq->page_pool, > + virt_to_head_page(buf_va)); IIUC you should pass the page_pool as the last argument to xdp_rxq_info_reg_mem_model() and then the page will be recycled by the core, you shouldn't release it. Not to mention the potential race in releasing the page _after_ giving its ownership to someone else. > - page = dev_alloc_page(); > + if (is_napi) { > + page = page_pool_dev_alloc_pages(rxq->page_pool); > + *from_pool = true; > + } else { > + page = dev_alloc_page(); FWIW if you're only calling this outside NAPI during init, when NAPI can't yet run, I _think_ it's okay to use page_pool_dev_alloc.. > + pprm.pool_size = RX_BUFFERS_PER_QUEUE; > + pprm.napi = &cq->napi; > + pprm.dev = gc->dev; > + pprm.dma_dir = DMA_FROM_DEVICE; If you're not setting PP_FLAG_DMA_MAP you don't have to fill in .dev and .dma_dir -- pw-bot: cr