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=1793732897; b=pbYoxp2JTFEYgxFzRZlG7vTkUCmwGJDoVwUu+bS0hOTmsBZtqKXZYqvXQ9bqjlREtAcH oPujxdVMqfZsHdRKf6UtsobKE5wSA2eKuYqA6OOxoXHebvhnPJZnQEWyolL1n/5oHUHJ4 j0DCP6bQRV2gvd7IeydZQRvWhgDeL5Io4eY4TMKijyEjIw63gKGZU/ujo9rsPpIw76Nx1 D5NSqpv1R3i+aVMgME6y93Uz2jO3TPGIB9yAzDZSD2EXxq/Miwoi/szdePx2WT/Ph27N9 eYAIUqjIN8gU/r+ZTeSHM1g3ZqmR+HmHPxLf8HXIbnht4s2ypkzy54w/s07uQv1VQ+g== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793732897; h=Received:DKIM-Signature:Date:From:To:Cc:Subject:Message-ID: References:MIME-Version:Content-Type:Content-Disposition:In-Reply-To; bh=z7grRwM8WCPf1zlbK4nUUkkFYLNOkxsXBBTP+mvK+4c=; b=KKOZZmyLp09/8zoSbcIJBTJZal8kwco1W5qzUIFQZpUEvVpNXYFhGYp3YZMUszyPpePJ Xreo779IHgV7D9YXFKGporXkyVu3GgQn+H7e/SnNozELytTQ17kN9uM4WsQit8M6r6ZZZ sA2KXtXhtkXeMF0kgqVmWDEvAITAuQhmBcEm5wX8EHr66iXNFHaPcLpooDKJ8Jbf6SUea zf9aKL9pmFSNTIZwM2iQiPCou7tbzYPbr4LpR45iD/GTdvAlMOpXsE3a3RuA71Gu1hMHO 1L9ktDyuYmpDjIjIQyNoZbhmx1W86Xiel1qgciM+nxBK4TRnmx+KC/Z4fGV1SGhxrSA== 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=O3TKZXNe; 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 7EAF8606A32F for ; Tue, 3 Nov 2026 19:08:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=O3TKZXNe Received: by smtp.kernel.org (Postfix) with ESMTPSA id CEADF1F000C1; Tue, 3 Nov 2026 19:08:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793732897; bh=z7grRwM8WCPf1zlbK4nUUkkFYLNOkxsXBBTP+mvK+4c=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=O3TKZXNecHe8eRQZymbl357ja5s5/vT3IHeQm6MhGvHFK5QPNE1fbbRac2ZmF5/+G crXqtNDZShkO1BeegusGfu+7n1ivVwRJYd7HpXE0W/+QqHZNcxwf9iZQcsrSJQVpkS OoXYciWFNtuFTZVcIY644I0MWCIy39JCY2sS9N3BJ54GFvYGRk5zaRrCwgcDCtcaWw sfvC6rdBPl5o3owyWUMcfQQ7U7q87cNkiceT+UBGml531OeRCHvImchlNj+j2fgMA9 HYZ5KlXD5ffyOa430iXwFGPZQo9YwfR9QSjY6JcO1LN5KbpkF1dKrOOMvMQ++CDod5 uvFTiT2lPsENA== Date: Tue, 3 Nov 2026 12:08:15 -0700 From: Keith Busch To: Liao Xuan Cc: axboe@kernel.dk, hch@lst.de, sagi@grimberg.me, linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org, default avatarZheng Tan Subject: Re: [PATCH 1/3] nvme: Add adaptive PCIe link rate switching function Message-ID: References: <85a11a4085d04a2823c04059702630cf34abf6d4.1790134954.git.liaoxuan@open-hieco.net> X-Mailing-List: linux-kernel@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-Disposition: inline In-Reply-To: <85a11a4085d04a2823c04059702630cf34abf6d4.1790134954.git.liaoxuan@open-hieco.net> On Tue, Nov 03, 2026 at 02:25:43PM +0800, Liao Xuan wrote: > Add support for dynamically adjusting the PCIe link rate of NVMe > devices based on I/O activity. The link is downgraded to a > configurable minimum rate during periods of low activity to save > power, and upgraded to the maximum supported rate as soon as the > workload exceeds a computed threshold, so that peak performance is > maintained under load. Pretty sure PCIe ASPM L1 states would save more power than downgrading the link rate, as well as have better entry/exit latency than a software driven monitor and link retrain.