From owner-svn-src-head@freebsd.org Fri Oct 27 02:27:23 2017 Return-Path: Delivered-To: svn-src-head@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id C7553E5946D for ; Fri, 27 Oct 2017 02:27:23 +0000 (UTC) (envelope-from wlosh@bsdimp.com) Received: from mail-io0-x232.google.com (mail-io0-x232.google.com [IPv6:2607:f8b0:4001:c06::232]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 7B50872CC6 for ; Fri, 27 Oct 2017 02:27:23 +0000 (UTC) (envelope-from wlosh@bsdimp.com) Received: by mail-io0-x232.google.com with SMTP id n137so9659896iod.6 for ; Thu, 26 Oct 2017 19:27:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bsdimp-com.20150623.gappssmtp.com; s=20150623; h=mime-version:sender:in-reply-to:references:from:date:message-id :subject:to:cc; bh=5A/zArWkcoyc5lO3mVaaxETHcHp4N0Km2sZe50S7r/U=; b=F7xZdIFWV+dxZwBS38/8gVljP1IoliKnBzFNGG2jSQr9npbAD/RsVrb4NfDig7Sjx+ GW6eqaSeBdxRPYkyA454v7YDrI/EQkzgkQxeir2PknCGlM7wD4GJkK5r51D/jJh51CfX sDTQuN4RQp9NTEFAN1/jUnOQTQofpitl4VqaZrMSA8S5cC+ehpmq/BO1WUwhLurMbkCc x+AR0X0gg5+6FNElUCCyV1TjXwtFeXWc/GqPo3aaw+0juIh3ZyfG64YNb2Geg81c5HDf 7J6AKFGKgAZvpRRoGuJCZImw1/eSORoy6h9zmMGxONpmM64AUjNz6OYL4mOUAadOg1Uw qATQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:sender:in-reply-to:references:from :date:message-id:subject:to:cc; bh=5A/zArWkcoyc5lO3mVaaxETHcHp4N0Km2sZe50S7r/U=; b=BoBGabKljWMKgfKwOfUnQlHmWfHUytMX1kU2LN9NClLXDbxw76kRx9kVn3bdGOqDgr 3RZry7268hqVHVitIc63Lst9C5AyAlQr0K+gKGp1nxJKnMijZW6bwTZ5iOxgD7iOlGJU JNm5x5PcdH42GYonOj2seaU2uRSnoEkxH1uUwq3K0eHkLLaGdg6uDuOofVRwhXRyep+w 0AUwNvaJJPcPZ3EdLoAxfKhWDIjWyRQOsqTxM+vzU5T4it4PxsPILOFz2eol7LZYQ4Bp pC++wVf+OTZePew/vd66aJGSz1TzhPSpbPdF5KEsYceLxn7yO64ZXhc+H1YviwcooEPY zpdA== X-Gm-Message-State: AMCzsaVlBZRwkts6k5x0/ucAOSDuQXxZNfAacc7SQvv6h8KfoF1UB40Z 9+VsTGCJV7SWoq+AKpO4Rar3ISv2Dt9KC4jGOYro9A== X-Google-Smtp-Source: ABhQp+TZr0IKK6gHF1s91p1ENIMbP2BxCuJKepKblC0Nl+3JQ109J0cg9dklVAmi/sQQGerJuRKOS98Q/PcVLamDWWQ= X-Received: by 10.36.184.5 with SMTP id m5mr1388046ite.69.1509071242870; Thu, 26 Oct 2017 19:27:22 -0700 (PDT) MIME-Version: 1.0 Sender: wlosh@bsdimp.com Received: by 10.79.57.22 with HTTP; Thu, 26 Oct 2017 19:27:22 -0700 (PDT) X-Originating-IP: [2603:300b:6:5100:68f3:90da:7630:94a5] In-Reply-To: References: <201710262253.v9QMrovZ009495@repo.freebsd.org> From: Warner Losh Date: Thu, 26 Oct 2017 20:27:22 -0600 X-Google-Sender-Auth: oCv8gFfkDYP9n-6k1fof6AEM694 Message-ID: Subject: Re: svn commit: r325026 - head/sys/cam/ata To: Alan Somers Cc: Warner Losh , "src-committers@freebsd.org" , "svn-src-all@freebsd.org" , "svn-src-head@freebsd.org" Content-Type: text/plain; charset="UTF-8" X-Content-Filtered-By: Mailman/MimeDel 2.1.23 X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 27 Oct 2017 02:27:23 -0000 On Thu, Oct 26, 2017 at 5:35 PM, Warner Losh wrote: > > > On Thu, Oct 26, 2017 at 5:04 PM, Alan Somers wrote: > >> On Thu, Oct 26, 2017 at 4:53 PM, Warner Losh wrote: >> > Author: imp >> > Date: Thu Oct 26 22:53:49 2017 >> > New Revision: 325026 >> > URL: https://svnweb.freebsd.org/changeset/base/325026 >> > >> > Log: >> > Always send STANDBY IMMEDIATE when shutting down >> > >> > To save SMART data and for a drive to understand that it's been nicely >> > shutdown, we need to send a STANDBY IMMEDIATE. Modify adaspindown to >> > use a local CCB on the stack. When we're panicing, used >> > xpt_polled_action rather than cam_periph_runccb so that we can SEND >> > IMMEDIATE after we've shutdown the scheduler. >> > >> > Sponsored by: Netflix >> > Reviewed by: scottl@, gallatin@ >> > Differential Revision: https://reviews.freebsd.org/D12799 >> > >> > Modified: >> > head/sys/cam/ata/ata_da.c >> >> Will this put the drive into a standby state just prior to a warm >> reboot? That could cause lengthy delays on the new boot while the >> drives spin up. That behavior caused a problem when the mpr driver >> did it to a JBOD full of 96 SATA drives. On the new boot, each drive >> spun up one at a time while they were being probed. Eventually the >> system paniced because run_interrupt_driven_hooks timed out. With >> mpr, I was able to fix the problem by setting hw.mpr.enable_ssu=0. >> > > That's a good question. The standard is silent about what, exactly, the > Standby state means. We already allow this to be disabled, and this commit > doesn't change that. It looks like IDLE IMMEDIATE also forces SMART media > non volatile to be flushed out. > > What do you suggest? > I see two paths forward. We need to flush the NV SMART data at reboot time. SSDs that we use, at least, consider it an unclean shutdown if you don't Idle the drive on reboot because part of that process does a COMINIT/COMRESET and if the drive is in the Active state, it ticks up the counter (and with at least one vendor can lose NV SMART data). So, path forward #1 is that we do STANDBY IMMEDIATE for SSDs in the RB_REBOOT case or all drives in the other cases. For HDD and RB_REBOOT we do only a IDLE IMMEDIATE which shouldn't spin the drives down. This seems to bake in what we know about storage devices and is easiest for the user. If we get it right, it's easier for the user. If we get it wrong, the user can disable all spin downs. Path forward #2 is to just make what we send a sysctl. This is unsatisfying and error-prone, but gives the most flexibility. I don't like this. I'd be curious if there's another viable path forward I'm not seeing that you might know. FWIW, we don't connect HDDs to our AHCI ports (they are all on MPT/MPS/MPR HBAs), so we've not seen any issues in the 6 or so months we've had this in the tree. Warner