Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754746Ab2FFHvg (ORCPT ); Wed, 6 Jun 2012 03:51:36 -0400 Received: from mga03.intel.com ([143.182.124.21]:8138 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751733Ab2FFHve (ORCPT ); Wed, 6 Jun 2012 03:51:34 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.71,315,1320652800"; d="scan'208";a="152223127" Message-ID: <4FCF0C03.9010400@linux.intel.com> Date: Wed, 06 Jun 2012 15:51:31 +0800 From: Chen Gong User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:12.0) Gecko/20120428 Thunderbird/12.0.1 MIME-Version: 1.0 To: Thomas Gleixner , "Luck, Tony" , "bp@amd64.org" , LKML Subject: Re: [tip:x86/urgent] x86/mce: Fix the MCE poll timer logic References: <1338863702-9245-1-git-send-email-gong.chen@linux.intel.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3099 Lines: 79 于 2012/6/6 15:10, tip-bot for Chen Gong 写道: > Commit-ID: 958fb3c51295764599d6abce87e1a01ace897a3e > Gitweb: http://git.kernel.org/tip/958fb3c51295764599d6abce87e1a01ace897a3e > Author: Chen Gong > AuthorDate: Tue, 5 Jun 2012 10:35:02 +0800 > Committer: Ingo Molnar > CommitDate: Wed, 6 Jun 2012 08:28:21 +0200 > > x86/mce: Fix the MCE poll timer logic > > In commit 82f7af09 ("x86/mce: Cleanup timer mess), Thomas just > forgot the "/ 2" there while cleaning up. > > Signed-off-by: Chen Gong > Acked-by: Thomas Gleixner > Cc: bp@amd64.org > Cc: tony.luck@intel.com > Link: http://lkml.kernel.org/r/1338863702-9245-1-git-send-email-gong.chen@linux.intel.com > Signed-off-by: Ingo Molnar > --- > arch/x86/kernel/cpu/mcheck/mce.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c > index 0a687fd..a97f3c4 100644 > --- a/arch/x86/kernel/cpu/mcheck/mce.c > +++ b/arch/x86/kernel/cpu/mcheck/mce.c > @@ -1274,7 +1274,7 @@ static void mce_timer_fn(unsigned long data) > */ > iv = __this_cpu_read(mce_next_interval); > if (mce_notify_irq()) > - iv = max(iv, (unsigned long) HZ/100); > + iv = max(iv / 2, (unsigned long) HZ/100); > else > iv = min(iv * 2, round_jiffies_relative(check_interval * HZ)); > __this_cpu_write(mce_next_interval, iv); > -- > 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/ In fact, there still exists another potential issue: static void __mcheck_cpu_init_timer(void) { struct timer_list *t = &__get_cpu_var(mce_timer); unsigned long iv = __this_cpu_read(mce_next_interval); setup_timer(t, mce_timer_fn, smp_processor_id()); if (mce_ignore_ce) return; __this_cpu_write(mce_next_interval, iv); if (!iv) return; ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Because the 2nd patch is not merged yet, so here iv is zero when this function is called, which means at the beginning, the poll timers are not registered until some other conditions trigger *add_timer_on*. t->expires = round_jiffies(jiffies + iv); add_timer_on(t, smp_processor_id()); } Another potential issue is in this function two smp_processor_id() are called. If conext changes during this procedure (I'm not sure if it can hapen, besides secondary_cpu kickoff, online/offline will call these functions, even in virtualization envrionment, etc.). So I think it will be better saving the value in the beginning of this function. Make sense? -- 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/