From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 E95802AE96; Wed, 16 Jul 2025 11:14:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752664448; cv=none; b=MB61LSw0TLFr27aMufVYj+i2ocPExD0VBNrXYK+7UP+Ep1V2Xa0AMvuYUBIcA3pNJ4T33VAUtqQnhWCaLrvAl5k+l0mCWKjgBC4FjwPysLbJDCBDfIRzHjjApOS+924TJTQdkpemV9CxqIat1OzUoXIEdQ4nsRA83HWQuasaih4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752664448; c=relaxed/simple; bh=J66qs/SXX72p0d4K0uZpcaeSmTq3Scy3eqJBX7RqLig=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=j5NCJUkbplUTpG65mpRYfjRQNUvcKXBm9cVACr3+X4cD3Y3zYogVRxMEYPOtVQt02j/XC4VCk3UNNVWw6D14Q1ADD3YX2sQRNqV2Fs2kfD3G5Xzts5sKYz8TxhoiuhlIkBwUZWq781/JorsXdSrZhCnplC00xyeCZZ4ntQfD018= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=LL1/fcFv; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="LL1/fcFv" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=cQP4FEYOudQe7oSNdm7jEn1TS7UAD20Psswd1K+XjMM=; b=LL1/fcFvUFVMocHUtmyWpc25s/ tJlzwnIzZxP1lqD7JyrMcihcByFCdWwNaPkUIOrzDJB/IHCbcB0EhCKFhf/l5RCZysIm7HFrPp2VQ MLKDQ7r5Op4YLsGLCpqddEuZhQQW16zSZLfwYqGa2n81Qj1WwHdc0xBFNI5tZRtX5TgEv8PV1D1C0 W5HPmRjpy99HkJYeioS5l7lB6CN2vCUvM6zCEzvrsQNpArOUbOlmy3mHjwNnOyM3zF1SrxnLqVIR6 yCV7jMkMYoOfaIeAlrSUnRZB/kmMYuuuT7Djr2Ke8hXjn3zR0z5PTc8DPVAuuZqI7oN++C7a0n6CN M9NSriHw==; Received: from hch by bombadil.infradead.org with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1uc05M-00000007WqV-1Cwh; Wed, 16 Jul 2025 11:14:04 +0000 Date: Wed, 16 Jul 2025 04:14:04 -0700 From: Christoph Hellwig To: Jakub Kicinski Cc: Christoph Hellwig , Dragos Tatulea , "David S. Miller" , Eric Dumazet , Paolo Abeni , Simon Horman , Andrew Lunn , Jens Axboe , parav@nvidia.com, Cosmin Ratio , Tariq Toukan , Pavel Begunkov , Mina Almasry , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, io-uring@vger.kernel.org Subject: Re: [PATCH v2 net-next] net: Allow SF devices to be used for ZC DMA Message-ID: References: <20250711092634.2733340-2-dtatulea@nvidia.com> <20250714181136.7fd53312@kernel.org> <20250715060649.03b3798c@kernel.org> Precedence: bulk X-Mailing-List: io-uring@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250715060649.03b3798c@kernel.org> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html On Tue, Jul 15, 2025 at 06:06:49AM -0700, Jakub Kicinski wrote: > On Mon, 14 Jul 2025 21:39:30 -0700 Christoph Hellwig wrote: > > > LGTM, but we need a better place for this function. netdevice.h is > > > included directly by 1.5k files, and indirectly by probably another 5k. > > > It's not a great place to put random helpers with 2 callers. > > > Maybe net/netdev_rx_queue.h and net/core/netdev_rx_queue.c? > > > I don't think it needs to be a static inline either. > > > > The whole concept is also buggy. Trying to get a dma-able device by > > walking down from an upper level construct like the netdevice can't work > > reliably. You'll need to explicitly provide the dma_device using either > > a method or a pointer to it instead of this guesswork. > > Yeah, I'm pretty sure we'll end up with a method in queue ops. > But it's not that deep, an easy thing to change. Why not get this right now instead of adding more of the hacky parent walking?