From owner-freebsd-current@FreeBSD.ORG Thu Feb 17 01:51:07 2005 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id D170516A4CE for ; Thu, 17 Feb 2005 01:51:07 +0000 (GMT) Received: from smtphost.cis.strath.ac.uk (smtphost.cis.strath.ac.uk [130.159.196.96]) by mx1.FreeBSD.org (Postfix) with ESMTP id 339A743D5D for ; Thu, 17 Feb 2005 01:51:07 +0000 (GMT) (envelope-from chodgins@cis.strath.ac.uk) Received: from [192.168.0.4] (chrishodgins.force9.co.uk [84.92.20.141]) j1H1oPRL009537; Thu, 17 Feb 2005 01:50:27 GMT Message-ID: <4213F98D.7020304@cis.strath.ac.uk> Date: Thu, 17 Feb 2005 01:55:25 +0000 From: Chris Hodgins User-Agent: Mozilla Thunderbird 1.0 (X11/20050204) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Julian Elischer References: <1108584730.95661.12.camel@server.mcneil.com> <20050216201716.GA28436@odin.ac.hmc.edu> <4213B3C8.3090508@centtech.com> <1108588393.12275.9.camel@server.mcneil.com> <20050216214031.GA2787@odin.ac.hmc.edu> <4213D3AA.70809@elischer.org> In-Reply-To: <4213D3AA.70809@elischer.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-CIS-MailScanner-Information: Please contact support@cis.strath.ac.uk for more information X-CIS-MailScanner: Found to be clean X-CIS-MailScanner-SpamCheck: not spam, SpamAssassin (score=0, required 6) X-CIS-MailScanner-From: chodgins@cis.strath.ac.uk cc: Eric Anderson cc: current@freebsd.org Subject: Re: where did all my memory go? (file system cache) X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 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: Thu, 17 Feb 2005 01:51:08 -0000 Julian Elischer wrote: > slightly off topic but.. > > Brooks Davis wrote: > >> On Wed, Feb 16, 2005 at 01:13:13PM -0800, Sean McNeil wrote: >> >> >> The concept that most of your memory should be entierly free when the >> system is not under load is simply wrong. The simplistic world view of >> memory being allocated to a specific task or entierly free simply isn't >> correct for all that it makes for nice graphs anyone can pretend they >> understand. You can produce some sort of aproximation of the output you >> see on other systems by modifying the program to include inactive memory >> in free memory. That's what I did with Ganglia. >> > > what I really want is a way to FORce certain pages out of cache. > In particular I need to verify teh correctness of the version on 2ndary > storage.. > > what I want is: > > int fd = open("myfile",...); > write1GBfiletodisk(fd, data); > ioctl(fd, PURGEFROMCACHE); > perform_md5(fd); > > and be sure that teh MD5 is that of what is on the disk. > not what is in RAM. > >> >> -- Brooks >> >> >> > > _______________________________________________ > freebsd-current@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-current > To unsubscribe, send any mail to "freebsd-current-unsubscribe@freebsd.org" > IANAE but could you not use the O_DIRECT flag with open? O_DIRECT eliminate or reduce cache effects HTH Chris