From owner-svn-src-all@freebsd.org Sun Dec 10 02:37:01 2017 Return-Path: Delivered-To: svn-src-all@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 18781EA1B88 for ; Sun, 10 Dec 2017 02:37:01 +0000 (UTC) (envelope-from wlosh@bsdimp.com) Received: from mail-io0-x236.google.com (mail-io0-x236.google.com [IPv6:2607:f8b0:4001:c06::236]) (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 CFB4D7FD1F for ; Sun, 10 Dec 2017 02:37:00 +0000 (UTC) (envelope-from wlosh@bsdimp.com) Received: by mail-io0-x236.google.com with SMTP id d14so6220409ioc.5 for ; Sat, 09 Dec 2017 18:37:00 -0800 (PST) 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:cc; bh=bYYtyUfjZBfz/lHk/F6Ykq/bvpCGLs6g3w/7vzpI0Mw=; b=rGdpGd420A8GkNf1Ii9UbuuWYGz+prHt9eXN6ZKnz0Y3yHSDgQ5Zct35rBne5A6Lk9 f+z0WSbCsnwAg2fsTSQepSUDtSe6JJFy5v++/aF5dmvL8/Oli6UMujyGgBlcWLFdgIEO tP2LItQOGZBtg5/139Ce61GCgt4a6PLYW4cF4BBAV8Oxr9olkzCzz2l6rosxPPoW/2Yv fUK6qTGGbariVfBbRcd/UJeBe+nVFiw9ItLVDyr3gatq3QN2z9PO3HjeDetRX3YaVgPV F86hhBIVh2TMQgzfnY/IJdGIw5OxineoDueR8GfFYe3hZ53IAGwVE8Pcyovjspd4cnUj IQ7A== 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:cc; bh=bYYtyUfjZBfz/lHk/F6Ykq/bvpCGLs6g3w/7vzpI0Mw=; b=uCaQgb+B5Ic2Kybj75/AyvAFzkeuhmqzlyMx96X0Ff73Gb+65OiqMvRhM++uHCAKf+ GXUgdmCnD0bkwyi1VyaLjwoHQeHj7K4BurZ3/oZuJZkyvG4CbXfBBeAOq0vW+Mu0lHsK aG8owAXXyxCUGzJuJHremLby/naWXnzXPUa/10L7mKqyVrjsn5wOnSh8cMgN579ngr7+ V4/dTwLKPR5/ciPqRVKuGvbfK0jHA4xFJsldZnMaLh0PnFeYvnWNzzvqWDLCczatM2pM 3hPzptxqbZ+LleaYNJDLLo8N3ja9bynVNMS3um8xF7WkhJET0I1cnk1CDL1vwFDuteNm vElQ== X-Gm-Message-State: AKGB3mJbLnHMX0ngsAE7soF48fpJq0qfxCZxKXUO0sAzx/SN9gWmFvPH JqWF8oQZJh1zOWDlgADjTVU8AgVuYr9elB6YH69Htn4x X-Received: by 10.107.52.140 with SMTP id b134mt23216765ioa.291.1512873419974; Sat, 09 Dec 2017 18:36:59 -0800 (PST) MIME-Version: 1.0 Sender: wlosh@bsdimp.com Received: by 10.79.108.204 with HTTP; Sat, 9 Dec 2017 18:36:59 -0800 (PST) X-Originating-IP: [2603:300b:6:5100:1052:acc7:f9de:2b6d] In-Reply-To: References: <201712091544.vB9FiVUI096790@repo.freebsd.org> From: Warner Losh Date: Sat, 9 Dec 2017 19:36:59 -0700 X-Google-Sender-Auth: JZyf-UZrCowTgk6H0I6IhUuyru4 Message-ID: Subject: Re: svn commit: r326731 - head/sys/ufs/ffs Cc: Mark Johnston , src-committers , "svn-src-all@freebsd.org" , "svn-src-head@freebsd.org" Content-Type: text/plain; charset="UTF-8" X-Content-Filtered-By: Mailman/MimeDel 2.1.25 X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.25 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 10 Dec 2017 02:37:01 -0000 On Sat, Dec 9, 2017 at 11:03 AM, Andriy Gapon wrote: > On 09/12/2017 17:44, Mark Johnston wrote: > > Some GEOMs do not appear to handle BIO_ORDERED correctly, meaning that > the > > barrier write may not work as intended. There's a few places we send down a BIO_ORDERED BIO_FLUSH command (see softdep_synchronize for one). Will those matter? As I've noted elsewhere: I'd really like to kill BIO_ORDERED since it has too many icky effects (and BIO_FLUSH + BIO_ORDERED isn't guaranteed to do, well, anything since it can turn into a NOP in a number of places. Plus many of the implementations of BIO_ORDERED assume the drive is like SCSI and you just set the right tag to make it 'ordered'. For ATA we issue a non NCQ command, which is a full drain of outstanding commands, send this command, then start them again which really shuts down the parallelism we implemented NCQ for :(. We do similar for NVME which is even worse. There we have multiple submission queues in the hardware. To simulated it, we do a similar drain, but that's going to get in the way as we move to NUMA and systems where we try to do the I/O entirely on one CPU (both submission and completion) and ordered I/O is guaranteed lock contention. Warner