Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753007AbaGJJb7 (ORCPT ); Thu, 10 Jul 2014 05:31:59 -0400 Received: from mga02.intel.com ([134.134.136.20]:56100 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752982AbaGJJb4 (ORCPT ); Thu, 10 Jul 2014 05:31:56 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.01,636,1400050800"; d="asc'?scan'208";a="541341827" Date: Thu, 10 Jul 2014 05:01:51 -0400 From: "Chen, Gong" To: Havard Skinnemoen Cc: Borislav Petkov , Tony Luck , Linux Kernel , Ewout van Bekkum Subject: Re: [PATCH 1/6] x86-mce: Modify CMCI poll interval to adjust for small check_interval values. Message-ID: <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> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="lEGEL1/lMxI0MVQ2" Content-Disposition: inline In-Reply-To: X-PGP-Key-ID: A43922C7 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 --lEGEL1/lMxI0MVQ2 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Jul 09, 2014 at 02:24:31PM -0700, Havard Skinnemoen wrote: > Date: Wed, 9 Jul 2014 14:24:31 -0700 > From: Havard Skinnemoen > To: Borislav Petkov > Cc: Tony Luck , Linux Kernel > , Ewout van Bekkum > Subject: Re: [PATCH 1/6] x86-mce: Modify CMCI poll interval to adjust for > small check_interval values. >=20 > On Wed, Jul 9, 2014 at 12:17 PM, Borislav Petkov wrote: > > > > 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 betwe= en > > > 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? >=20 > 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 <=3D check_interval always. --lEGEL1/lMxI0MVQ2 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJTvlZ+AAoJEI01n1+kOSLHnZ0QAJ1wOsCSjsfbcynQSG+r8Nbw 51VUhupIZWSrFSPEuz9uTop7crxS+wUgCPPyrfZ17sjeGBMopRJPce7NLeK2oeux QYaiNCeFHq+W+GY1xBgLoXbOnV+0GOmZFJ9V7znm4QXmzIEhls/Oz1z+8aUYoQlI ijIeR3e2m2WCzK4GPqRKMMoUFYyXXPo5PLGrp4Pv/XBoEI20QEe3+bkKsLFOqN13 62m/RElJkFUdpRAyshYQQguj39YieOo8fHosqrpBVUumGoKkEDoQ1qUNbssw2qcD IFw4T0QGv1Pz4OsBG/qBijRp7QHduhUGBXRRD3to3YyOHm0RmOlzJ2dWRJ9O9f+s u7f/4yLAlYVbJqQIv20wQgUytJfgHKc2gyEW1M9Nd/ciAy/LR7DFOVKHT5SQ03MI 6IUqXEWLpxR8Pg12tvdPFUIsbS+IXtruNB0B1CsNJvsGW9GyMBYPx9xgfJx4UdRx Se8kdhFOCoapTT4igTx6VZs7jNRPFDZL17uIqLZ3tFer4k2RFG1TOfRORMBwD0md zsG6vGpdvcXEnD7zGSA9S6gHbD4eVwu1A4r23649JNx0Uhm3UOLd9CYm9NreFlZl NaXOAcpB+S9DVoBZf6xv891kkSlYFeSB74qYUXlQtIBLZ6uWq/pCgCDhjYRqM4VD epAYR2dTrrUF9z9qhPEm =RzCx -----END PGP SIGNATURE----- --lEGEL1/lMxI0MVQ2-- -- 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/