Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755315Ab2FNI4U (ORCPT ); Thu, 14 Jun 2012 04:56:20 -0400 Received: from mga02.intel.com ([134.134.136.20]:65460 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754981Ab2FNI4S convert rfc822-to-8bit (ORCPT ); Thu, 14 Jun 2012 04:56:18 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.67,351,1309762800"; d="scan'208";a="157477088" From: "Liu, Jinsong" To: Konrad Rzeszutek Wilk CC: "xen-devel@lists.xensource.com" , "linux-kernel@vger.kernel.org" Subject: RE: xen/mce - mcelog at 100% cpu Thread-Topic: xen/mce - mcelog at 100% cpu Thread-Index: AQHNSZLddQXy2gd5YkW4phd9182UzZb5g2gw Date: Thu, 14 Jun 2012 08:56:11 +0000 Message-ID: References: <20120612124015.GB559@phenom.dumpdata.com> <20120613182458.GA5813@phenom.dumpdata.com> In-Reply-To: <20120613182458.GA5813@phenom.dumpdata.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.239.127.40] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1656 Lines: 42 Konrad Rzeszutek Wilk wrote: > On Tue, Jun 12, 2012 at 08:40:15AM -0400, Konrad Rzeszutek Wilk wrote: >> On Tue, Jun 12, 2012 at 07:51:03AM +0000, Liu, Jinsong wrote: >>>> From aa2ce7440f16002266dc8464f749992d0c8ac0e5 Mon Sep 17 00:00:00 >>>> 2001 >>> From: Liu, Jinsong >>> Date: Tue, 12 Jun 2012 23:11:16 +0800 >>> Subject: [PATCH] xen/mce: schedule a workqueue to avoid sleep in >>> atomic context >>> >>> copy_to_user might sleep and print a stack trace if it is executed >>> in an atomic spinlock context. >>> >>> This patch schedule a workqueue for IRQ handler to poll the data, >>> and use mutex instead of spinlock, so copy_to_user sleep in atomic >>> context would not occur. >> >> Ah much better. Usually one also includes the report of what the >> stack trace was. So I've added that in. > > So another bug which is that mcelog is spinning at 100% CPU (and only > under Xen). > > It seems to be doing: > > ppoll([{fd=4, events=POLLIN}, {fd=3, events=POLLIN}], 2, NULL, [], 8) > = 1 ([{fd=3, revents=POLLIN}]) read(3, "", 2816) > = 0 > ppoll([{fd=4, events=POLLIN}, {fd=3, events=POLLIN}], 2, NULL, [], 8) > = 1 ([{fd=3, revents=POLLIN}]) read(3, "", 2816) > > constantly. I will debug it. I have try at my platform, but fail to reproduce it. (You still use the config you send me last time, right?) Would you tell me your step? Thanks, Jinsong-- 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/