From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Kok, Auke" Subject: Re: [PATCH] vfs: Add a trace point in the mark_inode_dirty function Date: Wed, 11 Nov 2009 15:37:43 -0800 Message-ID: <4AFB4AC7.1090405@intel.com> References: <20091025225342.007138f5@infradead.org> <20091111020108.GA11423@localhost> <20091110223456.01ef355f@infradead.org> <4AFA6AEF.5060306@garzik.org> <20091111081905.270a4e55@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Arjan van de Ven , Jeff Garzik , "Wu, Fengguang" , "linux-kernel@vger.kernel.org" , "linux-fsdevel@vger.kernel.org" , Christoph Hellwig , Al Viro , "mingo@elte.hu" , Frederic Weisbecker To: "Frank Ch. Eigler" Return-path: Received: from mga02.intel.com ([134.134.136.20]:28189 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759667AbZKKXiI (ORCPT ); Wed, 11 Nov 2009 18:38:08 -0500 In-Reply-To: Sender: linux-fsdevel-owner@vger.kernel.org List-ID: Frank Ch. Eigler wrote: > Arjan van de Ven writes: > >> [...] ok let me rephrase that. What would a user DO with this inode >> number information, given that the filename is already passed on; >> what additional useful, not-infinitely-hard-to-get piece of >> information [...] > > Perhaps "infinitely hard" is the wrong criterion, but passing inode > numbers lets a tracepoint client track changes to the same file, even > though the file may be renamed/unlinked over time. If you already know what the file object is, sure. We're interested in the case where we have no clue what the file object actually is to begin with. Having a trace with a random inode number pop up and then disappear into thin air won't help much at all, especially if we can't map it back to something "real" on disk. in time. Auke