Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S272295AbTG3BCS (ORCPT ); Tue, 29 Jul 2003 21:02:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S272315AbTG3BCS (ORCPT ); Tue, 29 Jul 2003 21:02:18 -0400 Received: from unity.unh.edu ([132.177.137.40]:42369 "EHLO unity.unh.edu") by vger.kernel.org with ESMTP id S272295AbTG3BCR (ORCPT ); Tue, 29 Jul 2003 21:02:17 -0400 Date: Tue, 29 Jul 2003 21:02:12 -0400 From: Samuel Thibault To: Alan Cox Cc: Linux Kernel Mailing List Subject: Re: [RFC] single return paradigm Message-ID: <20030730010212.GD3100@bouh.unh.edu> Reply-To: Samuel Thibault Mail-Followup-To: Alan Cox , Linux Kernel Mailing List References: <20030726221655.GB1148@bouh.unh.edu> <1059302602.12754.3.camel@dhcp22.swansea.linux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1059302602.12754.3.camel@dhcp22.swansea.linux.org.uk> User-Agent: Mutt/1.4i-nntp X-MailScanner-Information: http://pubpages.unh.edu/notes/mailfiltering.html X-MailScanner: Found to be clean X-MailScanner-SpamCheck: not spam, SpamAssassin (score=-8.3, required 5, BAYES_10, IN_REP_TO, QUOTED_EMAIL_TEXT, REFERENCES, REPLY_WITH_QUOTES, USER_AGENT_MUTT) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1261 Lines: 27 Le dim 27 jui 2003 11:43:22 GMT, Alan Cox a tapot? sur son clavier : > On Sad, 2003-07-26 at 23:16, Samuel Thibault wrote: > > The "single return" paradigm of drivers/char/vt.c:tioclinux() surprised > > me at first glance. But I'm now trying to maintain a patch which adds > > probes at entry and exit of functions for performance instrumenting > > gcc will already dop that for you Indeed. The thing is that this automatic call only gives you the function address and its caller site (yes, it couldn't give much more), so you have to lookup symbols in the System.map, you can't do this with modules (at least for non-exported functions which don't appear in /proc/ksyms), and you can't get the return code. I'll yet add this possibility for quickly adding tracing to a particular file by just adding CFLAGS_file.o=-finstrument-functions to the Makefile, before progressively replacing it by hand-written probes with the wanted parameters. The single-exit issue still remains then. Thanks anyway, Regards, Samuel - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/