From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 27853 invoked by alias); 14 Nov 2006 19:23:56 -0000 Received: (qmail 27846 invoked by uid 22791); 14 Nov 2006 19:23:56 -0000 X-Spam-Status: No, hits=1.6 required=5.0 tests=AWL,BAYES_20,FORGED_RCVD_HELO,RCVD_IN_NJABL_DUL,RCVD_IN_SORBS_DUL,SPF_FAIL X-Spam-Check-By: sourceware.org Received: from c-24-5-197-144.hsd1.ca.comcast.net (HELO gateway.sf.frob.com) (24.5.197.144) by sourceware.org (qpsmtpd/0.31) with ESMTP; Tue, 14 Nov 2006 19:23:50 +0000 Received: from magilla.sf.frob.com (magilla.sf.frob.com [198.49.250.228]) by gateway.sf.frob.com (Postfix) with ESMTP id 49476357B; Tue, 14 Nov 2006 11:23:48 -0800 (PST) Received: by magilla.sf.frob.com (Postfix, from userid 5281) id EDCA3180059; Tue, 14 Nov 2006 11:23:47 -0800 (PST) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit From: Roland McGrath To: Mike Mason Cc: systemtap@sources.redhat.com Subject: Re: Pointer chain paranoia In-Reply-To: Vara Prasad's message of Tuesday, 14 November 2006 11:12:16 -0800 <455A1510.7070004@us.ibm.com> X-Windows: don't get frustrated without it. Message-Id: <20061114192347.EDCA3180059@magilla.sf.frob.com> Date: Tue, 14 Nov 2006 19:25:00 -0000 X-IsSubscribed: yes Mailing-List: contact systemtap-help@sourceware.org; run by ezmlm Precedence: bulk List-Subscribe: List-Post: List-Help: , Sender: systemtap-owner@sourceware.org X-SW-Source: 2006-q4/txt/msg00427.txt.bz2 The deref macro expands to code that is quite cheap. The inline code is just the load instruction about like the compiler would normally generate. The extra code is in the exception-handling lookaside section, which adds bloat to the total .ko size but not to the normal module code paths that will ever be occupying I-cache in normal operation.