From owner-freebsd-current@FreeBSD.ORG Sun Mar 21 14:05:23 2010 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id B060E1065679; Sun, 21 Mar 2010 14:05:23 +0000 (UTC) (envelope-from mavbsd@gmail.com) Received: from fg-out-1718.google.com (fg-out-1718.google.com [72.14.220.154]) by mx1.freebsd.org (Postfix) with ESMTP id DEE0B8FC24; Sun, 21 Mar 2010 14:05:22 +0000 (UTC) Received: by fg-out-1718.google.com with SMTP id d23so158042fga.13 for ; Sun, 21 Mar 2010 07:05:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:sender:message-id:date:from :user-agent:mime-version:to:cc:subject:references:in-reply-to :content-type:content-transfer-encoding; bh=BRJ41r/r91Fq55DvNWe6LznhUMxpmLSNAg11fbo4tys=; b=c7H3BUIot8BPnUVeIqVVf7kEIL8dDdTg2RDfY4J93sKY8LqtXpFWKmHOHvrFltqe3U pZLwFk8Hdtqo9lbFzkQBFzLHqkBYpoRZce88Iu0h29lTwWn4FcRpiqEAeWjNRmW8LhDc x35+Fcfg7G6l3fiWo5i8TfxJWGp8gddNpZD0c= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=sender:message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:content-type:content-transfer-encoding; b=ofxrZSgSLrIcBX/hC8/q0gtZtPNeYhHv/QdrtnOOAtiJ599BsnD2ZTQcWI+MT+f3b/ saHVVWMwQfiScHRaHYzoce6uMewIxujxrRjnUo8ULVF3njrT2APHUYPGVTnepz9BSHom LCN97/uW2jCcRpmoU18mkJHArX0H4KBzLH7RQ= Received: by 10.87.2.15 with SMTP id e15mr1915544fgi.22.1269180321552; Sun, 21 Mar 2010 07:05:21 -0700 (PDT) Received: from mavbook.mavhome.dp.ua (pc.mavhome.dp.ua [212.86.226.226]) by mx.google.com with ESMTPS id 16sm921439fxm.0.2010.03.21.07.05.20 (version=SSLv3 cipher=RC4-MD5); Sun, 21 Mar 2010 07:05:20 -0700 (PDT) Sender: Alexander Motin Message-ID: <4BA6279E.3010201@FreeBSD.org> Date: Sun, 21 Mar 2010 16:05:18 +0200 From: Alexander Motin User-Agent: Thunderbird 2.0.0.23 (X11/20091212) MIME-Version: 1.0 To: Ivan Voras References: <1269109391.00231800.1269099002@10.7.7.3> <1269120182.00231865.1269108002@10.7.7.3> <1269120188.00231888.1269109203@10.7.7.3> <1269123795.00231922.1269113402@10.7.7.3> <1269130981.00231933.1269118202@10.7.7.3> <1269130986.00231939.1269119402@10.7.7.3> <1269134581.00231948.1269121202@10.7.7.3> <1269134585.00231959.1269122405@10.7.7.3> In-Reply-To: <1269134585.00231959.1269122405@10.7.7.3> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: freebsd-current@freebsd.org, freebsd-arch@freebsd.org Subject: Re: Increasing MAXPHYS X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 21 Mar 2010 14:05:23 -0000 Ivan Voras wrote: > Julian Elischer wrote: >> You can get better throughput by using TSC for timing because the geom >> and devstat code does a bit of timing.. Geom can be told to turn off >> it's timing but devstat can't. The 170 ktps is with TSC as timer, >> and geom timing turned off. > > I see. I just ran randomio on a gzero device and with 10 userland > threads (this is a slow 2xquad machine) I get g_up and g_down saturated > fast with ~~ 120 ktps. Randomio uses gettimeofday() for measurements. I've just got 140Ktps from two real Intel X25-M SSDs on ICH10R AHCI controller and single Core2Quad CPU. So at least on synthetic tests it is potentially reachable even with casual hardware, while it completely saturated quad-core CPU. > Hmm, it looks like it could be easy to spawn more g_* threads (and, > barring specific class behaviour, it has a fair chance of working out of > the box) but the incoming queue will need to also be broken up for > greater effect. According to "notes", looks there is a good chance to obtain races, as some places expect only one up and one down thread. -- Alexander Motin