From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.ebshome.net (gate.ebshome.net [64.81.67.12]) (using TLSv1 with cipher EDH-RSA-DES-CBC3-SHA (168/168 bits)) (Client CN "gate.ebshome.net", Issuer "gate.ebshome.net" (not verified)) by ozlabs.org (Postfix) with ESMTP id 7A5D367A64 for ; Fri, 18 Feb 2005 11:43:32 +1100 (EST) Date: Thu, 17 Feb 2005 16:43:27 -0800 From: Eugene Surovegin To: Stephen Williams Message-ID: <20050218004327.GB10915@gate.ebshome.net> References: <42152ADD.8040104@icarus.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <42152ADD.8040104@icarus.com> Cc: linuxppc-embedded@ozlabs.org Subject: Re: Linux processes, tempfs and programs List-Id: Linux on Embedded PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Thu, Feb 17, 2005 at 03:38:05PM -0800, Stephen Williams wrote: > My embedded system is structured such that the main user-mode > processes that are being run are downloaded and executed on demand. > I'm currently downloading the executable to an ext3 system on the > CompactFlash, but there is really no reason to use non-volatile > memory so I'm thinking to download to a tempfs directory and > execute from there. > > But if I do that, I want to remove the program from the directory > after I start it, so that the file does not take up ram space. Will > that actually work? I'm using exec(2) to execute the program file > wherever it is downloaded. Will a subsequent unlink of the file > have a result, or will the file continue to take up space as > backing store for the executable? I think unlink will remove the file from directory (so you won't be able to see it with ls), but it will still continue to to take space - you're right it will be used as backing store, at least for read-only segments, which can be discarded if memory is tight. Even if you mlock all executable in memory, I think there will be still at least one reference to this file, which will prevent freeing tmpfs memory. -- Eugene