From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out162-62-57-49.mail.qq.com (out162-62-57-49.mail.qq.com [162.62.57.49]) (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 6764218732B for ; Thu, 3 Apr 2025 07:05:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=162.62.57.49 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743663960; cv=none; b=MddkPgb8cN2vGuspfSKMCUNtZmKoybFpXpIGIGMo/0AlbmKW9isseicXGgNulM93tuzIxhuIG0DfOYE/YMJH4k/9QODOBaDbJzlNEKO4PcTvC5kZTZ6k1XIJlEoIQuhRY2W0UNOCuCuBUyCFkx03SovTIDJmrt4BSWNLVmq6Plc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743663960; c=relaxed/simple; bh=mHGwwiszjPz6p1aVgkTBS0vD6k297ari2KmfSue73EE=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=WmH4SwR1Cev3IlhXd2O7p1HEldl+m7JvinSJnbkv5dnKwQ+HvDT+pRcgrSa0ZFY9TskbzN0kcqBvbV32vUYJj4sPfdmKmyL7LZy35sn4++HXbxJAnnJ5fNo844Gp/qnFPlJ8yKtCuKH1iQJmZjY1EdV3ph/npvryAdqMVuQNiXo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=qq.com; spf=pass smtp.mailfrom=qq.com; dkim=pass (1024-bit key) header.d=qq.com header.i=@qq.com header.b=GoTtDTcD; arc=none smtp.client-ip=162.62.57.49 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=qq.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=qq.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=qq.com header.i=@qq.com header.b="GoTtDTcD" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=qq.com; s=s201512; t=1743663940; bh=bhVWt//b5MQhMSww4VsQj4VZ/Hr+hhUj7oNoEyoZMhY=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=GoTtDTcDAPDWHA7TbxhFgKccWxDHL5Gn3o4HV7+czHLkrsV60iMwnGdunFdoeuNqu IltbHNQ6VJQHqIZaQDizp2VlwU5qQ9h1Q0sOvYY9ELkdsllQYTfd7lzYH28p7BpkQm CdsQCf9wLhuy+7DZbOP7NKEAOWjut1fHJwv2qJH8= Received: from [10.42.13.21] ([116.128.244.169]) by newxmesmtplogicsvrsza36-0.qq.com (NewEsmtp) with SMTP id 165AE892; Thu, 03 Apr 2025 15:05:37 +0800 X-QQ-mid: xmsmtpt1743663937twb6ozg5x Message-ID: X-QQ-XMAILINFO: NUxwpkvPscRuoSR7hR69LKTJvUlW2/y5zdcPjjkuv7QVQ7Vuq1eguOMx2ABbgS vXfD71YDHvZiUoo8293e1EHrdHZyUCnxcXqSidujhpbY6ogYhEVn/Isd1cgXGzMdTDGKHNDk+7ZR GckBEgb9OGo01AdNhuxcColPDTkxyA1/H9CDrTs/kCa8L3/tqig9xKh84YcBjDIkwqF7CPsGO3v6 fdpM5T1niv7p3UEPG/tenB7sHvkslgHLtaOGgrRk9oQjOZGHgrrziMYJDwS2nu52I1tCBoRcltJL +2txeS0B18HuPpfDGB7moMSuYZGaKo3jzF34WTq0an87X+YRFwaOsg4eg1A8oEsAiFO4+lUPpYx4 48L+CFod+bkAGdDQd73VdwMoc5lsKOTpjUb/tu0ETERqiwwKng9D9F6qJcQTJMSC88G7o92tVZn1 KK6ulDoAq0PB8bRq5T6mtm8C7FFCBaSlBRYpYnfeC9XaHTiF2IotulGTqWcd49wAN66MUVeplzkI AkWk4FM7y6ewmzavrL67Ex0C2eo6W4exniOM9oQa6ARb0EEIV5HC9Abwf1cqd6yqmm/hGJcDdiIa yOwxrA4NNFG3fPGlYZxif2iURtYcPV0crr9NUnaTVH1rfIPr5T8Nn9VUNjwj5ChN3yP2dnqML8QJ ud6VIIppS4TQN43XRg2dIGHGCFFzC466xWAOBAT+KbITU6BnF4zirOKmQSldRvAZD2bzRIvmETo9 1V0Fxr32aq1wHXLx7m+3qk8qHVs7upHtZ3jM80x9BoSa9NdL2niGqpubWG2oPw8DozJZXc6WqjMg CQseCddLuks/pF2pZbig3bGVXSAx/TBBEkICrjNPlI5aAsYm1gjEZiTrF3wCjoWrjUNPHjUs3O3e 2wTHZHJEMrX+Uwt3ehCHk3uq1irq3s9PYmEWGzXgZRs+UVyQK2bDxHRylIgiZIgZ0e0C1oO4C9H+ eqCStb7pEYOn+7d66Z8w== X-QQ-XMRINFO: NyFYKkN4Ny6FSmKK/uo/jdU= X-OQ-MSGID: <2895d817-0316-4df3-9253-347e87bcb953@qq.com> Date: Thu, 3 Apr 2025 15:05:37 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 0/3] nvme: Add sysfs interface for APST configuration management To: Christoph Hellwig Cc: kbusch@kernel.org, axboe@kernel.dk, sagi@grimberg.me, chaitanyak@nvidia.com, linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org, Yaxiong Tian , alexey.bogoslavsky@wdc.com References: <20250403042504.GB22360@lst.de> Content-Language: en-US From: Yaxiong Tian In-Reply-To: <20250403042504.GB22360@lst.de> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit 在 2025/4/3 12:25, Christoph Hellwig 写道: > On Tue, Apr 01, 2025 at 05:22:06PM +0800, Yaxiong Tian wrote: >> From: Yaxiong Tian >> >> This series enhances NVMe APST (Autonomous Power State Transition) support by: >> 1. Adding warnings for PST table allocation failures > > That looks fine. > >> 2. Exposing APST tables via sysfs for runtime inspection >> 3. Providing per-controller sysfs interface for APST configuration > > Who is going to use this and how? We'll need proper tools for that, > and in general I'd prefer to have a common set of policies for APST > configurations and not random people coming up with lots of random > policies. These two patches don't fundamentally change the APST configuration policy, but rather enable users to configure various APST parameters in real-time across different devices. As mentioned in commit ("nvme: extend and modify the APST configuration algorithm"): 1）This patch only introduces partial functionality from the Windows driver - it doesn't enable dynamic regeneration of the APST table when switching between AC power and battery power. 2) Additionally, using default configurations on certain brand SSDs has been observed to increase power consumption. Therefore, when a system contains multiple drives and users require different configurations for AC vs battery power scenarios, real-time APST configuration updates across different devices become necessary.It must be said that configuring these parameters is difficult for average users, but they can still use the original default settings. However, for advanced users looking to optimize their devices, this provides them with the necessary interface. As for providing suitable tools for users, I suppose every advanced user has their own preferences and approaches. For example, one could trace device idle time statistics through trace events (e.g., nvme_complete_rq → nvme_setup_cmd) and use that data as a reference to configure apst_primary_timeout_ms. For example，The device idle time distribution under specific operating conditions is shown below (unit: nanoseconds): We can set apst_primary_timeout_ms to 32ms, which ensures that over 99% of NVMe commands remain unaffected by APST. @intervals: [512, 1K) 749 |@@@@@@@@ | [1K, 2K) 4856 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@| [2K, 4K) 1002 |@@@@@@@@@@ | [4K, 8K) 756 |@@@@@@@@ | [8K, 16K) 413 |@@@@ | [16K, 32K) 36 | | [32K, 64K) 14 | | [64K, 128K) 9 | | [128K, 256K) 13 | | [256K, 512K) 8 | | [512K, 1M) 4 | | [1M, 2M) 4 | | [2M, 4M) 3 | | [4M, 8M) 4 | | [8M, 16M) 3 | | [16M, 32M) 0 | | [32M, 64M) 6 | | [64M, 128M) 5 | | [128M, 256M) 5 | | [256M, 512M) 15 | | [512M, 1G) 7 | |