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 8240F308F05; Mon, 27 Apr 2026 22:44:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777329872; cv=none; b=q/TSrzFRt6jKdAHq47NxCtKV9jT6pSz/J1tpD4//G+BrMUk4Wdzi1BU5E+zV4h82T+l8vqEDigA/fSSA2IjsroL51PAUsvmRcnF6GRj2Dtl+k5aKxbdzpBU8i/gDnszBCDBplQGj7Yg+qzzvmffcJxEYp6IY18VXahCvnj8CUTQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777329872; c=relaxed/simple; bh=R4LMRbc5mg+8UIeUjMdT+Efo6WUGtul9TLdlExK2ELg=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=b4I7Zo4AwGZQTno7qf7eXzV/7kFVPUuITcE82Py3Sa+r1x1fdKwopcKRG9v/yjZehScNvb6DFBCplKpqebH/LmNJ8SmE+w8KUSbsfdTrWBYRBROxFwaN+/exxMcg4rKmi88UarAjjc2tg5q4HNT4WrtYfTtVBTgdFHCDbkRcuHk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=c6RgOq+V; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="c6RgOq+V" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BD4E5C19425; Mon, 27 Apr 2026 22:44:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1777329872; bh=R4LMRbc5mg+8UIeUjMdT+Efo6WUGtul9TLdlExK2ELg=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=c6RgOq+VoUwVn47JnHkDjnuu/vZqEpPZOlm1WZEXW/vRsvPtcEGYyFKv9mV4QRI4g sHTuo03n9gQ59wKHHTU91b6z0CY/HRapOAxL2u/H9v68niu59kvE7L5CJ2Iy6q5Fcz kZd2yb5mLU38GFtoTykuyYSTBnimjRDQyc3jh7DMUtOdDR3mxaT+iXvNAGF1i8Trea iBZ4c3jzhxByCX3W8ZYweQjMeL1Muhoo7vEde1Ax8Q7FfB/RsIs7uz1aGjkDSFpWCl r8WFeBXaND+y38YxAN8HcdklDfKfu+lLMFdQ1u/b4uYKWE6Ulb9sPXLQ7YyM35dihO /dYNut8aAZ1Ng== Date: Mon, 27 Apr 2026 15:44:29 -0700 From: Jakub Kicinski To: Dipayaan Roy Cc: kys@microsoft.com, haiyangz@microsoft.com, wei.liu@kernel.org, decui@microsoft.com, andrew+netdev@lunn.ch, davem@davemloft.net, edumazet@google.com, pabeni@redhat.com, leon@kernel.org, longli@microsoft.com, kotaranov@microsoft.com, horms@kernel.org, shradhagupta@linux.microsoft.com, ssengar@linux.microsoft.com, ernis@linux.microsoft.com, shirazsaleem@microsoft.com, linux-hyperv@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-rdma@vger.kernel.org, stephen@networkplumber.org, jacob.e.keller@intel.com, dipayanroy@microsoft.com, leitao@debian.org, kees@kernel.org, john.fastabend@gmail.com, hawk@kernel.org, bpf@vger.kernel.org, daniel@iogearbox.net, ast@kernel.org, sdf@fomichev.me, yury.norov@gmail.com Subject: Re: [RFC PATCH net-next] net: mana: Force single RX buffer per page under SWIOTLB bounce modes Message-ID: <20260427154429.6a141824@kernel.org> In-Reply-To: References: Precedence: bulk X-Mailing-List: bpf@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 Mon, 27 Apr 2026 07:41:11 -0700 Dipayaan Roy wrote: > In both cases, sub-page RX buffer fragments allocated via page_pool may > not be compatible with bounce buffering in this mode, leading to failures > in the RX path. What does it mean to not be compatible with swiotlb? Normally that indicates that DMA API is mis-used.