From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756443Ab0IGK5a (ORCPT ); Tue, 7 Sep 2010 06:57:30 -0400 Received: from fgwmail7.fujitsu.co.jp ([192.51.44.37]:48682 "EHLO fgwmail7.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756211Ab0IGK50 convert rfc822-to-8bit (ORCPT ); Tue, 7 Sep 2010 06:57:26 -0400 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 From: KOSAKI Motohiro To: Pekka Enberg Subject: Re: disabling group leader perf_event Cc: kosaki.motohiro@jp.fujitsu.com, Ingo Molnar , Avi Kivity , Pekka Enberg , Tom Zanussi , =?ISO-8859-1?Q?Fr=E9d=E9ric?= Weisbecker , Steven Rostedt , Arnaldo Carvalho de Melo , Peter Zijlstra , linux-perf-users@vger.kernel.org, linux-kernel In-Reply-To: References: <20100906154737.GA4332@elte.hu> Message-Id: <20100907141319.C90D.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT X-Mailer: Becky! ver. 2.50.07 [ja] Date: Tue, 7 Sep 2010 19:57:22 +0900 (JST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > As for the intermediate form, you might want to take a look at Dalvik: > > http://www.netmite.com/android/mydroid/dalvik/docs/dalvik-bytecode.html > > and probably ParrotVM bytecode too. The thing to avoid is stack-based > instructions like in Java bytecode because although it's easy to write > interpreters for them, it makes JIT'ing harder (which needs to convert > stack-based representation to register-based) and probably doesn't > lend itself well to stack-constrained kernel code. (offtopic) Afaik, NetBSD plan to include lua interpreter in kernel. it is optimized embedded environment. (more offtopic) in kernel interpreter is needed some concern. 1) restricted stack size (typical userland VM often use >100K stack size) 2) restrected memory allocation, especially high order allocation often fail. 3) GC often makes unacceptable large lag especially on UP kernel. etc etc So, We can't apply rich interpreter (e.g. Dalvik, Parrrot) so easily. I think. personally I prefer minimum component. Thanks.