From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755606Ab3LDACV (ORCPT ); Tue, 3 Dec 2013 19:02:21 -0500 Received: from mga02.intel.com ([134.134.136.20]:1239 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754662Ab3LDACS (ORCPT ); Tue, 3 Dec 2013 19:02:18 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.93,821,1378882800"; d="scan'208";a="438034817" From: Andi Kleen To: Alexei Starovoitov Cc: Ingo Molnar , Steven Rostedt , Peter Zijlstra , "H. Peter Anvin" , Thomas Gleixner , Masami Hiramatsu , Tom Zanussi , Jovi Zhangwei , Eric Dumazet , linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH tip 0/5] tracing filters with BPF References: <1386044930-15149-1-git-send-email-ast@plumgrid.com> Date: Tue, 03 Dec 2013 16:01:59 -0800 In-Reply-To: <1386044930-15149-1-git-send-email-ast@plumgrid.com> (Alexei Starovoitov's message of "Mon, 2 Dec 2013 20:28:45 -0800") Message-ID: <87fvq9cwlk.fsf@tassilo.jf.intel.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Alexei Starovoitov writes: Can you do some performance comparison compared to e.g. ktap? How much faster is it? While it sounds interesting, I would strongly advise to make this capability only available to root. Traditionally lots of complex byte code languages which were designed to be "safe" and verifiable weren't really. e.g. i managed to crash things with "safe" systemtap multiple times. And we all know what happened to Java. So the likelyhood of this having some hole somewhere (either in the byte code or in some library function) is high. -Andi