Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752401AbaGJRRA (ORCPT ); Thu, 10 Jul 2014 13:17:00 -0400 Received: from mail-ob0-f170.google.com ([209.85.214.170]:58260 "EHLO mail-ob0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752371AbaGJRQ6 (ORCPT ); Thu, 10 Jul 2014 13:16:58 -0400 MIME-Version: 1.0 In-Reply-To: <20140710090150.GB10182@gchen.bj.intel.com> References: <1404925766-32253-1-git-send-email-hskinnemoen@google.com> <1404925766-32253-2-git-send-email-hskinnemoen@google.com> <20140709191747.GB5249@pd.tnic> <20140710090150.GB10182@gchen.bj.intel.com> Date: Thu, 10 Jul 2014 10:16:56 -0700 Message-ID: Subject: Re: [PATCH 1/6] x86-mce: Modify CMCI poll interval to adjust for small check_interval values. From: Havard Skinnemoen To: "Chen, Gong" Cc: Borislav Petkov , Tony Luck , Linux Kernel , Ewout van Bekkum Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jul 10, 2014 at 2:01 AM, Chen, Gong wrote: > On Wed, Jul 09, 2014 at 02:24:31PM -0700, Havard Skinnemoen wrote: >> On Wed, Jul 9, 2014 at 12:17 PM, Borislav Petkov wrote: >> > Why min 3 polls? How do you come up with exactly that frequency? >> >> The idea is that if we make it equal to check_interval, it might >> bounce back and forth a lot. So we need to divide by something, and 8 >> seems like a nice, safe value, and it seems to work well. We're not >> opposed to considering other values, of course (e.g. 2 and 4 might >> work well too, but with somewhat higher risk of ping-ponging). > That value looks chosen a little bit at will. How about updating > CMCI_POLL_INTERVAL when check_interval is changed to ensure > CMCI_POLL_INTERVAL <= check_interval always. I guess that would work equally well, but we still need to determine the magic number of how much less we want CMCI_POLL_INTERVAL to be. Havard -- 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/