Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754065Ab1EXHi4 (ORCPT ); Tue, 24 May 2011 03:38:56 -0400 Received: from casper.infradead.org ([85.118.1.10]:47029 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753940Ab1EXHix (ORCPT ); Tue, 24 May 2011 03:38:53 -0400 Subject: Re: [PATCH v3] x86, vt-d: enable x2apic opt out From: David Woodhouse To: "Valdis.Kletnieks@vt.edu" Cc: Youquan Song , "Song, Youquan" , "linux-kernel@vger.kernel.org" , "akpm@linux-foundation.org" , "mingo@elte.hu" , "tglx@linutronix.de" , "hpa@zytor.com" , "hpa@linux.intel.com" , "Kay, Allen M" , "Siddha, Suresh B" , "Sankaran, Rajesh" , "Mallick, Asit K" , "Liu, Kent" Date: Tue, 24 May 2011 08:38:47 +0100 In-Reply-To: <17321.1306210686@localhost> References: <1306161148-3987-1-git-send-email-youquan.song@intel.com> <7457.1306203521@localhost> <20110524153614.GA19080@linux-youquan.bj.intel.com> <17321.1306210686@localhost> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.0.1 (3.0.1-1.fc15) Content-Transfer-Encoding: 7bit Message-ID: <1306222728.2627.49.camel@i7.infradead.org> Mime-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1194 Lines: 27 On Tue, 2011-05-24 at 05:18 +0100, Valdis.Kletnieks@vt.edu wrote: > Do we want an actual WARN there, complete with stack traceback and > all? > > Or did you intend a pr_warn or printk(KERN_WARNING or similar? The traceback has been very useful in other BIOS issues, because it gets tracked and counted on kerneloops.org along with platform identification. So we have been able to track down the major offenders of some of the most egregious BIOS stupidities and make *some* progress on getting them to improve the untested dross they habitually turn out. On *this* occasion perhaps a printk might suffice. After all, this X2APIC_OPT_OUT was invented specifically as a way to allow the BIOS engineers to get away without fixing their bugs. But then again, it would also be useful to track how many people are doing it, and I cannot think of a *legitimate* reason for a BIOS having to set it. So on balance I'm happier with the WARN(). -- dwmw2 -- 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/