Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759379Ab3EWPzp (ORCPT ); Thu, 23 May 2013 11:55:45 -0400 Received: from mx1.redhat.com ([209.132.183.28]:57785 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758788Ab3EWPzo (ORCPT ); Thu, 23 May 2013 11:55:44 -0400 Date: Thu, 23 May 2013 11:55:32 -0400 From: Dave Jones To: Ming Lei Cc: Takashi Iwai , "H. Peter Anvin" , Linux Kernel , x86@kernel.org, fenghua.yu@intel.com Subject: Re: microcode loading got really slow. Message-ID: <20130523155532.GE16419@redhat.com> Mail-Followup-To: Dave Jones , Ming Lei , Takashi Iwai , "H. Peter Anvin" , Linux Kernel , x86@kernel.org, fenghua.yu@intel.com References: <20130523144800.GB16419@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 880 Lines: 20 On Thu, May 23, 2013 at 11:27:08PM +0800, Ming Lei wrote: > > Yes, in your case, everything is fine in the kernel itself. And no > > microcode update is needed for new CPU, thus no firmware. > > Can the driver decide if the CPU need microcode? Or there will > be the microcode for the CPU in future? The kernel can't know. The microcode updates are asynchonously released from the kernel. I might be running a months old kernel, and get a new microcode tomorrow. The kernel handles this by looking for a file with a name matching the cpu family/model/stepping. (See how they are formed in /lib/firmware/intel-ucode/*) DAve -- 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/