From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751170AbeEHEBc (ORCPT ); Tue, 8 May 2018 00:01:32 -0400 Received: from mail.kernel.org ([198.145.29.99]:55290 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750710AbeEHEBa (ORCPT ); Tue, 8 May 2018 00:01:30 -0400 Date: Tue, 8 May 2018 13:01:27 +0900 From: Masami Hiramatsu To: Steven Rostedt Cc: linux-kernel@vger.kernel.org, Ingo Molnar , Namhyung Kim , Tom Zanussi , Arnaldo Carvalho de Melo , linux-trace-users@vger.kernel.org, linux-kselftest@vger.kernel.org, shuah@kernel.org, Ravi Bangoria Subject: Re: [PATCH v7 00/16] tracing: probeevent: Improve fetcharg features Message-Id: <20180508130127.c9de04e9d9c93a90e9891ae0@kernel.org> In-Reply-To: <20180507113003.66045d18@gandalf.local.home> References: <152465856498.26224.16969986455942749517.stgit@devbox> <20180503181137.6d82d897@gandalf.local.home> <20180505004828.9b75b6802472f09b0d2de5b8@kernel.org> <20180504120642.354cdd1f@gandalf.local.home> <20180505113803.45700179a93091b114ec6984@kernel.org> <20180506005143.7bd9030db298fcfbade73434@kernel.org> <20180507113003.66045d18@gandalf.local.home> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.31; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 7 May 2018 11:30:03 -0400 Steven Rostedt wrote: > On Sun, 6 May 2018 00:51:43 +0900 > Masami Hiramatsu wrote: > > > OK, now I think it is a time to introduce new unified interface for dynamic events, > > tracefs/dynamic_events and make uprobe_events and kprobe_events as symbolic-links > > to the new interface file. > > So basically make one file that does all the work? > > I'm not sure we can keep the other files as symbolic links. Because we > don't want the kprobe_events showing up in the uprobe_events file, and > vice versa. We need to keep all this backward compatible. Good catch! Can't we check which file the user opened? If not, even though we can setup a filter in ops->open(). > > But I do like the idea of one file to rule them all, approach. Thanks! > > -- Steve > > > > > > Actually, there is no reason we split those 2 interfaces, since > > both have similar, but very clear syntax differences. > > > > o Uprobe event definition > > p[:[GRP/]EVENT] PATH:OFFSET [FETCHARGS] : Set a uprobe > > r[:[GRP/]EVENT] PATH:OFFSET [FETCHARGS] : Set a return uprobe (uretprobe) > > -:[GRP/]EVENT : Clear uprobe or uretprobe event > > > > o Kprobe event definition > > p[:[GRP/]EVENT] [MOD:]SYM[+offs]|MEMADDR [FETCHARGS] : Set a probe > > r[MAXACTIVE][:[GRP/]EVENT] [MOD:]SYM[+0] [FETCHARGS] : Set a return probe > > -:[GRP/]EVENT : Clear a probe > > > > At first, it is clear that those can share the parser. 2nd, it is easy to > > distinguish those, because Uprobe event must require the PATH which starts > > with '/', on the other hand, Kprobe event must NOT start with '/'. > > (both SYM and MOD will start with alphabet or '_', of course MEMADDR > > will start with digits) > > > > If we can merge those to unified dynamic_events interface, I think > > 'f[:[GRP/]EVENT] SYM(CAST)' is also acceptable, since it is no more > > only for kprobe/uprobe. We can directly add some other dynamic > > events via dynamic_events interface. ;) > > > > Thank you, > > > -- Masami Hiramatsu