From owner-freebsd-fs@freebsd.org Thu Sep 6 08:11:44 2018 Return-Path: Delivered-To: freebsd-fs@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 506FAFF3180 for ; Thu, 6 Sep 2018 08:11:44 +0000 (UTC) (envelope-from marklmi@yahoo.com) Received: from sonic301-21.consmr.mail.gq1.yahoo.com (sonic301-21.consmr.mail.gq1.yahoo.com [98.137.64.147]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id D032F8C33A for ; Thu, 6 Sep 2018 08:11:43 +0000 (UTC) (envelope-from marklmi@yahoo.com) X-YMail-OSG: XRcrgKQVM1mSWPBGlNVW429e7n3UiCsXGzwYeoGMYyWhgUwESPFoe72B5WjZ8KL laLOaL9H0kTvTs4a2ZVsRj5vFORo09j4mQjOWQ_bkF7AFcVXnQ1joV2W127qJXHR4XZqQUC0S9RQ 50nDvf6YaEGFbQlvkYaajb5GmS9yrzx9i2ARPKxnKuge7noNIMfI40PvQR49IhZ3f6xRjO7YtCb1 EbkGNRTteVM_TPW9zw58k3BekvYPK4xBRMpF7.rCNQMfO7yv6w3bNjPXs04DcGgvhPt0N4t3oGmr XE.DBaDixyMWEteiWJ1KhwdJb6zJ1LUpaX9bz248_G1jTwbGJ9yyTnAl9l61ScYjQPuiNoR6RV3j RB5nRMcF4CcJ9jpiE3Fje1aYhCEA8dJvSyUEo9s3rOlWon3X5REgk4N4j8Ht3pCCBw3p.EcvHuaY rZj_BLwhpJO0bd6SUBp8uF08VIpl48t4uTbCG.EEIIxHbKKbzfVr9g8HcadWXlCZ5wX3rQD9r8it cn8yWwuU0sJ4UrAlBH.0MWzm6_7vjYGf.IHgGQ7jshuC9Mc2Dsh0V9VAz55SDi7.vWJY9.2FDxal 1AHdyBxSEWU9wHn4YgX2si1JxCmHY64cRK9RwxGQ.JKWibW0Hm.3j2uc6YJsD6YpNeORIhuWeCjY nDk3Avm43pJ8gBjOWc82aWbHO5q4L9xYP5twcps7km6WUwDcJzmbN99Okj11YeqDcITnA3NwNR2F aO49tMeVMYIoVZZ0kmehKIy.5SfYhBwD7GsNZHPscOzA.S6E24LGcPAPH2gYSsbUB4NZDpUNm_VW hpVFknI97BVwdiC2Mahc0ZrumWm2p5fz38dcvZZNfrgkX9aBU7Ue7DPZksf0YpbW_ew6Ugt.ib82 D6qhgOWHv2bw84v1PFvBI.neq.3T3J5kM6PEl_fPPzGKVLUplUzGv2B7cwprhJzk9CRYj1wp0u7l ozG31aJtyn56rpLdajMTgewNDe3WRPIsvTym6xDQzg1SxCOqH9EovP96zfF6vY4kM8CmutH2e6h6 Khwv47j9_ Received: from sonic.gate.mail.ne1.yahoo.com by sonic301.consmr.mail.gq1.yahoo.com with HTTP; Thu, 6 Sep 2018 08:11:35 +0000 Received: from ip70-189-131-151.lv.lv.cox.net (EHLO [192.168.0.105]) ([70.189.131.151]) by smtp430.mail.gq1.yahoo.com (Oath Hermes SMTP Server) with ESMTPA ID 26140bc27fd95585bacf261bc215ab57; Thu, 06 Sep 2018 08:11:31 +0000 (UTC) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 11.5 \(3445.9.1\)) Subject: Re: CFT: TRIM Consolodation on UFS/FFS filesystems From: Mark Millard In-Reply-To: <20180906001217.GB818@www.zefox.net> Date: Thu, 6 Sep 2018 01:11:30 -0700 Cc: FreeBSD Filesystems , bob prohaska Content-Transfer-Encoding: quoted-printable Message-Id: <97765759-B81A-44F0-98A0-F7B9D05F7432@yahoo.com> References: <201809052207.w85M7GS2000773@chez.mckusick.com> <20180906001217.GB818@www.zefox.net> To: Kirk McKusick X-Mailer: Apple Mail (2.3445.9.1) X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.27 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 06 Sep 2018 08:11:44 -0000 [Just correcting a bad claim about the timing of the two buildworld runs that were referenced. It could be misleading to Kirk for his requested information.] On 2018-Sep-5, at 5:12 PM, bob prohaska wrote: > On Wed, Sep 05, 2018 at 03:07:16PM -0700, Kirk McKusick wrote: >>=20 >> It is a bit tricky to just turn off TRIM and then measure it, because >> in the immediate aftermath of its having been used, it will leave >> behind a legacy of easier to use flash areas yet not have the cost >> of keeping them cleaned up. So, it might initially look like enabling >> TRIM is a bad idea. Thus you would have to run many installworlds >> without TRIM enabled to see what the long-term result of not using >> TRIM turns out to be. >>=20 >=20 > Just for fun I ran a (somewhat absurd) -j4 buildworld on RPI3 using 6 = GB of swap, > three on USB and three on microSD, just to see if anything interesting = (bad) happened.=20 > The process took about 24 hours, and the oversuppy of swap didn't = cause any obvious=20 > problems. Next I turned on TRIM and re-ran the buildworld script. =20 >=20 > There were no obvious problems, but the process took about an extra = hour. buildworld did not take an hour longer for one vs. the other based on the timestamps in the log files: trim off: World build started on Sun Sep 2 20:28:12 PDT 2018 . . . World build completed on Mon Sep 3 21:35:47 PDT 2018 So somewhat over 25 hours 7 minutes. trim on: World build started on Tue Sep 4 00:02:36 PDT 2018 . . . World build completed on Wed Sep 5 01:12:47 PDT 2018 So somewhat over 25 hours 10 minutes. I get an under 5 minute difference from those timestamps. > Since /var, /tmp and /usr were all on USB there was no hope TRIM could = be > any help on the busy filesystems. TRIM was enabled on microSD, but it = had > little to do. There does seem to be a modest penalty for using TRIM = when > it can't help much. >=20 > Is there any hope of implementing something like TRIM for USB on the = Pi? > It appears that congestion on USB is a serious bottlneck from time to = time > just for traffic with /tmp and /usr. Adding swap to the mix makes it = worse. >=20 > Log files are at > http://www.zefox.net/~fbsd/rpi3/swaptests/r338342/3gbsd_3gbusb/ > in case they're of interest. =3D=3D=3D Mark Millard marklmi at yahoo.com ( dsl-only.net went away in early 2018-Mar)