From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794500265; b=HD3cBoGD74xqSz+RsHKvSDrtH2lhxE5atJ0safUEyHIPTqXUmqRp4hm4HBPgDE63HJhH a1+g3tStS0cUvmU2L1+kFFrgKxO63bWGui7MN/BYJ73/yor5c2Xuo6wFt1ou3FLSrQ1jA iSJqN4kk+HnUx/ndm+nxImQi80puuapkJItGcqmjDR/bci/oCEaB7dsaUQxbNJQQZ0Xsp KS0r2bwti5dnv8lFMW0o8vrb/NeIZStG2QYnxcQBygKXIOamyjHeR0v85f10NpV4oaoqs BXoBMXtqeVtGMlO1AN/VzPuWw5cxVpz42o9IUp2BRHOPT3Oqnqp6d/GPiDxKUahXWgg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794500265; h=Received:DKIM-Signature:Date:From:To:Cc:Subject:Message-ID: In-Reply-To:References:MIME-Version:Content-Type: Content-Transfer-Encoding; bh=8l0HT/Ti+u8eRLgZezAEnobZ3Iu0FPfd7TRkU2hPmno=; b=wnMWTNO2xcIsP2D7creNgSLQ5PFWn8T6Vqs7NnSGNQj+9QxJUbC1xN4JHA6+TZPIlEFZ 7zGkUPXDVKIBYsR8m9X8eFD82JnHH8tHiKzsNRBez49MY8xVBV8eVVGapjoHfukv812UE z7SgVvSJ73wfZ3O40TDETGbPFtve1vblpj6N8FTxRkUMDM0JFxPJvQt8L+zVLKrrtySCw KDbYFn3XAYHisxav1OF6/dufFfuo4IiVBvQOFEVQ9pIVc8k6yerjzCU6IjsoNaOjz0q6q spV1FS1+XHVKAegP8EKjGUBoRdXHbWnAWPmM4Mbh62c3I5hNjBH8LA4HR/oguES/HXg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=Qc6hgnR2; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 52D2A606A31C; Thu, 12 Nov 2026 16:17:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=Qc6hgnR2 Received: by smtp.kernel.org (Postfix) with ESMTPSA id B4EEE1F000C4; Thu, 12 Nov 2026 16:17:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794500265; bh=8l0HT/Ti+u8eRLgZezAEnobZ3Iu0FPfd7TRkU2hPmno=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=Qc6hgnR2W4DJiPEIowjdv491mN7jlnpsbYKrfOoMSw3NqKSnRTilIWhx2gemPz4rR 7YQ10guacmkFz3VzfC3AyymD0tKwrz8aFcVe46pxTocfmQTiOmlYVQp8VPUZQ50Mxn JgN8ZZAElDzhbozo5ODMOwtE+ABwsb5Qb51vcNAOAf93AnCLWke2RF0DhbSYEPMzbj nwR9JEO6ChXDQI4eKXbgN/QwidkYXtZ0eSE9GblZRgBSE/wOZHAMaoJqFqYByOQkKn 3/YFAvxqBXBVZkQYlVyVE3qiz7A/hD3ahQivkGpkKclfvK85dajvB/zIk0QDaiSmUx otTxmHWNl3YJQ== Date: Thu, 12 Nov 2026 08:17:44 -0800 From: Jakub Kicinski To: Paolo Abeni Cc: Robin Murphy , m.szyprowski@samsung.com, netdev@vger.kernel.org, iommu@lists.linux.dev, joro@8bytes.org, will@kernel.org, =?UTF-8?B?QmrDtnJuIFTDtnBlbA==?= Subject: Re: [PATCH 04/11] dma-contiguous: pass the NUMA node to dma_alloc_contiguous() Message-ID: <20261112081744.3ba9cd82@kernel.org> In-Reply-To: References: <20261106184433.761422-1-kuba@kernel.org> <20261106184433.761422-5-kuba@kernel.org> X-Mailing-List: netdev@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Thu, 12 Nov 2026 16:43:51 +0100 Paolo Abeni wrote: > >> I'm possibly over-thinking here, but AFAICS there are a bunch of dma_map_ops that > >> are using dev_to_node(): > >> > >> dma_iommu_alloc_coherent() in arch/powerpc/kernel/dma-iommu.c > >> vio_dma_iommu_alloc_coherent() in arch/powerpc/platforms/pseries/vio.c > >> gart_alloc_coherent() in arch/x86/kernel/amd_gart_64.c > >> > >> With this series they will stop using the driver provided numa node. > >> Probably not a blocker but possibly worth to call out? > > > > Nothing "stops" - this series adds a *new* interface by which > > drivers can now indicate a specific preferred node, but DMA API > > backends are still free to ignore the caller-provided hint and > > continue doing whatever they want. This is already called out all > > over the series in commit messages, documentation and comments > > including the one above. > > I mean: the series also replaces the old hacks with the new APIs usage > in a few drivers, and in the above cases there could be actual > regressions. > > But I guess we could handle them if and when they will surface. I know AI helps people surface unlikely cases but we need to draw the line somewhere.