Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933373AbZKXUrP (ORCPT ); Tue, 24 Nov 2009 15:47:15 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933027AbZKXUrO (ORCPT ); Tue, 24 Nov 2009 15:47:14 -0500 Received: from mx1.redhat.com ([209.132.183.28]:44518 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933025AbZKXUrN (ORCPT ); Tue, 24 Nov 2009 15:47:13 -0500 Date: Tue, 24 Nov 2009 21:41:52 +0100 From: Oleg Nesterov To: Andi Kleen Cc: Alexey Dobriyan , Ananth Mavinakayanahalli , Christoph Hellwig , "Frank Ch. Eigler" , Ingo@firstfloor.org, "Molnar References: <20091124200220.GA5828@redhat.com> <87my2bwtno.fsf@basil.nowhere.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87my2bwtno.fsf@basil.nowhere.org> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1436 Lines: 42 On 11/24, Andi Kleen wrote: > > Oleg Nesterov writes: > > > From: Roland McGrath > > > > This adds the utrace facility, a new modular interface in the kernel > > for implementing user thread tracing and debugging. This fits on top > > of the tracehook_* layer, so the new code is well-isolated. > > Could we just drop the tracehook layer if this finally merged > and call the low level functions directly? Not sure I understand. Tracehooks are trivial inline wrappers on top utrace calls, > It might have been reasonably early on when it was still out of tree, > but longer term when it's integrated having strange opaque hooks > like that just makes the coder harder to read and maintain. Well, I don't think the code will be better if we remove tracehooks. For example. tracehook_report_syscall_entry() has a lot of callers in arch/, each callsite should be changed to do if ((task_utrace_flags(current) & UTRACE_EVENT(SYSCALL_ENTRY)) && utrace_report_syscall_entry(regs)) ret = -1; // this depends on machine instead of simply calling tracehook_report_syscall_entry(). What is the point? But again, perhaps I misunderstood you. Oleg. -- 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/