Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751201AbZIJEp7 (ORCPT ); Thu, 10 Sep 2009 00:45:59 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750916AbZIJEp7 (ORCPT ); Thu, 10 Sep 2009 00:45:59 -0400 Received: from mail-yw0-f175.google.com ([209.85.211.175]:59418 "EHLO mail-yw0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750842AbZIJEp6 (ORCPT ); Thu, 10 Sep 2009 00:45:58 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=subject:from:to:cc:in-reply-to:references:content-type:date :message-id:mime-version:x-mailer:content-transfer-encoding; b=fZQNKeysWQNqCSzkJT2urAZfVO8Qqh0kHN+hflj8DXdXni+WYBXJZ0ZbPEXg/v9y3z 1y/IP+Zc77Yx1WH9Tg3JH5jFFq6x0CGt1HwOCMOYlnnMSrCKQ3mBO4xYHJjS+oGMhYbn tFl0i/YbdCEharLZ0VkjAj2ZjkZ+Z7HtIDGtI= Subject: Re: [PATCH 4/6] perf_counter: Add PERF_COUNTER_IOC_SET_FILTER ioctl From: Tom Zanussi To: Li Zefan Cc: Peter Zijlstra , Ingo Molnar , Steven Rostedt , Frederic Weisbecker , Jason Baron , LKML In-Reply-To: <4AA71080.7030503@cn.fujitsu.com> References: <4AA4C04D.1050201@cn.fujitsu.com> <4AA4C0B3.3070300@cn.fujitsu.com> <1252341871.7959.37.camel@laptop> <20090907164852.GA6485@elte.hu> <1252342545.7959.42.camel@laptop> <1252393315.10919.4.camel@tropicana> <4AA71080.7030503@cn.fujitsu.com> Content-Type: text/plain Date: Wed, 09 Sep 2009 23:45:57 -0500 Message-Id: <1252557957.6431.2.camel@tropicana> Mime-Version: 1.0 X-Mailer: Evolution 2.24.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1441 Lines: 39 On Wed, 2009-09-09 at 10:18 +0800, Li Zefan wrote: > >>>> Hrm,.. not at all sure about this.. what are the ABI implications? > >>> I think the ABI should be fine if it's always a sub-set of C syntax. > >>> That would be C expressions initially. Hm? > >> Right, so I've no clue what filter expressions look like, and the > >> changelog doesn't help us at all. It doesn't mention its a well > >> considered decision to henceforth freeze the expression syntax. > >> > >> Of course, since filters so far only work with tracepoint things, and > >> since you can only come by tracepoint things through debugfs, and since > >> anything debugfs is basically a free-for-all ABI-less world, we might be > >> good, but then this is a very ill-defined ioctl() indeed. > >> > >> So please, consider this well -- there might not be a second chance. > >> > > > > I've been meaning to write up something about the event filters - here's > > a first stab that hopefully helps explain them... > > > > Great! > > Reviewed-by: Li Zefan > > Could you add your SOB and send it to Ingo? > > Some nitpicks below: Sure, I'll send a new version shortly - thanks for the suggestions. Tom -- 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/