Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756180AbaGITR6 (ORCPT ); Wed, 9 Jul 2014 15:17:58 -0400 Received: from mail.skyhub.de ([78.46.96.112]:41894 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755810AbaGITRz (ORCPT ); Wed, 9 Jul 2014 15:17:55 -0400 Date: Wed, 9 Jul 2014 21:17:47 +0200 From: Borislav Petkov To: Havard Skinnemoen Cc: Tony Luck , linux-kernel@vger.kernel.org, Ewout van Bekkum Subject: Re: [PATCH 1/6] x86-mce: Modify CMCI poll interval to adjust for small check_interval values. Message-ID: <20140709191747.GB5249@pd.tnic> References: <1404925766-32253-1-git-send-email-hskinnemoen@google.com> <1404925766-32253-2-git-send-email-hskinnemoen@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <1404925766-32253-2-git-send-email-hskinnemoen@google.com> 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 On Wed, Jul 09, 2014 at 10:09:21AM -0700, Havard Skinnemoen wrote: > From: Ewout van Bekkum > > The CMCI poll interval was updated to pick the minimum interval between > the original 30 seconds and the check_interval divided by 8 (minimum of > 3 polls). Why min 3 polls? How do you come up with exactly that frequency? > This resolves a bug where the CMCI storm handler is unable to return to > interrupt mode from polling mode, if the check_interval shorter than the > CMCI poll interval. This problem is caused by the mce_timer_fn function > which only allows the poll interval to be incremented up to the > check_interval, while the mce_intel_adjust_timer function requires the > poll interval to be greater than the CMCI poll interval before leaving > the CMCI_STORM_ACTIVE state. Interesting. So it seems you guys want to set the check_interval to something < 30 secs. Out of curiosity, what is your use case which requires such small check_interval setting? Maybe we need to redesign and simplify this intervals thing to make it more user-friendly... Btw, on a related note, we're working on a small mechanism which collects correctable errors in the kernel and when a certain count for a physical error address has been reached, we soft-offline that page. We'd appreciate it if you guys took a look and told us whether it makes sense to you: http://lkml.kernel.org/r/1404242623-10094-1-git-send-email-bp@alien8.de Thanks. -- Regards/Gruss, Boris. Sent from a fat crate under my desk. Formatting is fine. -- -- 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/