From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from 009.lax.mailroute.net (009.lax.mailroute.net [199.89.1.12]) (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 C2D7F1D0DE6; Thu, 22 Aug 2024 19:29:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=199.89.1.12 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724354971; cv=none; b=huMud2LxsW7IhzfRbFShc7ppl3ZG/tNvLct4aLGxH/4Ms/t39QDw9XTEVYjEMFq0uegmHRc/3DXm3sAYOOwGMCLHmw4gD3Tpbi8MON5r6tRBfdjJ5nlukCWmOzhR3zUNP83x2gcDTAngRfyi2OliElVQPCpZQULOim0uxIuBl/M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724354971; c=relaxed/simple; bh=9ZEgusTWJU2HXLnzHir15+nHfQOEL9J2dmjPlBk4gZ4=; h=Message-ID:Date:MIME-Version:Subject:To:References:From: In-Reply-To:Content-Type; b=kDgVgdBAyWKK2gVCJqtJJfHOWDkG2juaVCeYCuug5TytmDhz1CaxzBZKh7UsN8htL10qWQNTMFyigTYKaKPH21HBBS85PMAiqtAJpeNQAWCqsJX4UzqegmqdtJFL4ylqVeRMA6I3oq3loY2AGGkjTQZHG62zPBbbgWbUhOFlhiI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=acm.org; spf=pass smtp.mailfrom=acm.org; dkim=pass (2048-bit key) header.d=acm.org header.i=@acm.org header.b=Q80JPWcP; arc=none smtp.client-ip=199.89.1.12 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=acm.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=acm.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=acm.org header.i=@acm.org header.b="Q80JPWcP" Received: from localhost (localhost [127.0.0.1]) by 009.lax.mailroute.net (Postfix) with ESMTP id 4WqYDT0MPfzlgVnK; Thu, 22 Aug 2024 19:29:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=acm.org; h= content-transfer-encoding:content-type:content-type:in-reply-to :from:from:content-language:references:subject:subject :user-agent:mime-version:date:date:message-id:received:received; s=mr01; t=1724354964; x=1726946965; bh=9ZEgusTWJU2HXLnzHir15+nH fQOEL9J2dmjPlBk4gZ4=; b=Q80JPWcPlkv2CO7rMQcOBV9cJQj4CxnH8yk4cRxO 1nfR9UrEJAzCs41yxpGZg2MZWpK6InAbCRglO7WakUDR4dP6dMVqJMlaIINenVTD rGn+PuDbqf59N9yxrvJq0CyK9ZHs3XK2tYrmI9RKb70tVcS0t0cUwRx/dy1/rvZq Laar2dL9MOWAc4J5YUs/zfBnhh49UdXKCAIymaCND9Kba2legHFyDhYRbFUfCF4h c/w3qL6ZtGV7m5jA3NroU3bHhypV41Wshg8HYHB/+b1Ngm5XpizUduyPJgd2pz8W UNIB+/2P3SWRDWs+ITC9BqqXG0o0j1UgeU+KWsWuZTJ6yg== X-Virus-Scanned: by MailRoute Received: from 009.lax.mailroute.net ([127.0.0.1]) by localhost (009.lax [127.0.0.1]) (mroute_mailscanner, port 10029) with LMTP id itsm-lJJiOpf; Thu, 22 Aug 2024 19:29:24 +0000 (UTC) Received: from [100.66.154.22] (unknown [104.135.204.82]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: bvanassche@acm.org) by 009.lax.mailroute.net (Postfix) with ESMTPSA id 4WqYDL0lXRzlgVnF; Thu, 22 Aug 2024 19:29:21 +0000 (UTC) Message-ID: Date: Thu, 22 Aug 2024 12:29:21 -0700 Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC 0/7] Introduce swiotlb throttling To: mhklinux@outlook.com, kbusch@kernel.org, axboe@kernel.dk, sagi@grimberg.me, James.Bottomley@HansenPartnership.com, martin.petersen@oracle.com, kys@microsoft.com, haiyangz@microsoft.com, wei.liu@kernel.org, decui@microsoft.com, robin.murphy@arm.com, hch@lst.de, m.szyprowski@samsung.com, petr@tesarici.cz, iommu@lists.linux.dev, linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org, linux-scsi@vger.kernel.org, linux-hyperv@vger.kernel.org, linux-coco@lists.linux.dev References: <20240822183718.1234-1-mhklinux@outlook.com> Content-Language: en-US From: Bart Van Assche In-Reply-To: <20240822183718.1234-1-mhklinux@outlook.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 8/22/24 11:37 AM, mhkelley58@gmail.com wrote: > Linux device drivers may make DMA map/unmap calls in contexts that > cannot block, such as in an interrupt handler. Although I really appreciate your work, what alternatives have been considered? How many drivers perform DMA mapping from atomic context? Would it be feasible to modify these drivers such that DMA mapping always happens in a context in which sleeping is allowed? Thanks, Bart.