From owner-freebsd-fs@FreeBSD.ORG Mon Oct 3 20:09:34 2011 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 9F878106566C for ; Mon, 3 Oct 2011 20:09:34 +0000 (UTC) (envelope-from ivoras@gmail.com) Received: from mail-wy0-f182.google.com (mail-wy0-f182.google.com [74.125.82.182]) by mx1.freebsd.org (Postfix) with ESMTP id E67E28FC16 for ; Mon, 3 Oct 2011 20:09:33 +0000 (UTC) Received: by wyj26 with SMTP id 26so4817293wyj.13 for ; Mon, 03 Oct 2011 13:09:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:from:date :x-google-sender-auth:message-id:subject:to:cc:content-type :content-transfer-encoding; bh=v+wrECGMQ/wvtWPw0FH89c24T35s4PDe6zmGiv6QkKs=; b=c+rmDcG8RBdSg9UZx4tz45qtPjiKyDad0cw49e6ugV2K/JVabHl2nVtAWLl1spmXP0 ePAwsrd8V3/S0e2DluBGrH7aY6495017qiKs+ZW5sMzjFa7P9moDRmBAjlcdcJGBLYsQ e4IHAHrxxgpA4bXoRHl58oBnNETuldWOG4ZSQ= Received: by 10.227.6.199 with SMTP id a7mr351176wba.74.1317670679086; Mon, 03 Oct 2011 12:37:59 -0700 (PDT) MIME-Version: 1.0 Sender: ivoras@gmail.com Received: by 10.180.107.130 with HTTP; Mon, 3 Oct 2011 12:37:19 -0700 (PDT) In-Reply-To: References: <20111002020231.GA70864@icarus.home.lan> From: Ivan Voras Date: Mon, 3 Oct 2011 21:37:19 +0200 X-Google-Sender-Auth: fZpGeGIJiYUVw5uw8GGU3Jt6Dgg Message-ID: To: Xin LI Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Cc: freebsd-fs@freebsd.org Subject: Re: is TMPFS still highly experimental? X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 03 Oct 2011 20:09:34 -0000 On 3 October 2011 20:37, Xin LI wrote: > It's mostly "normal" configuration -- 6GB RAM, 14GB swap, ZFS as /usr; > Initialized with pgbench -i -s 500 pgbench. Ok, this should be enough ~~ 7 GB database on a 6 GB machine. >> =C2=A0 =C2=A0 =C2=A0 =C2=A0- run pgbench & observe the results. > > pgbench -t 20000 -c 64 -S pgbench > > Can't seem to reproduce: > > # df -Httmpfs > Filesystem =C2=A0 =C2=A0Size =C2=A0 =C2=A0Used =C2=A0 Avail Capacity =C2= =A0Mounted on > tmpfs =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A010G =C2=A0 =C2=A0 69k =C2=A0 =C2= =A0 10G =C2=A0 =C2=A0 0% =C2=A0 =C2=A0/tmp > > Any suggestions? Can't think of anything to add :) I don't think increasing the database size would affect it much. Comparing what you did to my original report at http://www.mail-archive.com/freebsd-current@freebsd.org/msg126491.html, it seems like that bug is gone! But my machine was one of the bigger ones (for that time) - AFAIK 24 GB RAM and many cores (16?). Maybe there is some race condition which is exposed on large machines. >> This should create really bad contention problem for memory between >> postgresql and ZFS, which should manifest itself in tmpfs shrinking to 0 >> bytes free. >> >> If you don't get this problem then great, it might be solved! I don't have the equipment now to test it myself but I agree that based on what you posted it looks solved.