Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751744AbbBUTX6 (ORCPT ); Sat, 21 Feb 2015 14:23:58 -0500 Received: from mail-wi0-f174.google.com ([209.85.212.174]:51320 "EHLO mail-wi0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751448AbbBUTX5 (ORCPT ); Sat, 21 Feb 2015 14:23:57 -0500 Date: Sat, 21 Feb 2015 20:23:52 +0100 From: Ingo Molnar To: Borislav Petkov Cc: Andy Lutomirski , Oleg Nesterov , Rik van Riel , x86@kernel.org, linux-kernel@vger.kernel.org, Linus Torvalds Subject: Re: [RFC PATCH] x86, fpu: Use eagerfpu by default on all CPUs Message-ID: <20150221192352.GA10027@gmail.com> References: <20150221093150.GA27841@gmail.com> <20150221163840.GA32073@pd.tnic> <20150221172914.GB32073@pd.tnic> <20150221183952.GD8406@gmail.com> <20150221191527.GC32073@pd.tnic> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150221191527.GC32073@pd.tnic> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 859 Lines: 28 * Borislav Petkov wrote: > > I'd sleep a lot better if we had some runtime debug > > flag to be able to do run-to-run comparisons on the > > same booted up kernel, or so. > > Let me take a look whether we could so some knob... The > nice thing is, code uses use_eager_fpu() to check stuff > so we should be able to clear the cpufeature flag. Either that, or you could quickly hack those checks to use panic_timeout, add an 'extern int panic_timeout;' and after bootup do: echo 0 > /proc/sys/kernel/panic echo 1 > /proc/sys/kernel/panic to switch between the modes? Thanks, Ingo -- 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/