Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757254AbZGIHTR (ORCPT ); Thu, 9 Jul 2009 03:19:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755475AbZGIHTD (ORCPT ); Thu, 9 Jul 2009 03:19:03 -0400 Received: from fgwmail7.fujitsu.co.jp ([192.51.44.37]:54577 "EHLO fgwmail7.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752635AbZGIHTB (ORCPT ); Thu, 9 Jul 2009 03:19:01 -0400 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 Message-ID: <4A5599D2.7080604@jp.fujitsu.com> Date: Thu, 09 Jul 2009 16:18:42 +0900 From: Hidetoshi Seto User-Agent: Thunderbird 2.0.0.22 (Windows/20090605) MIME-Version: 1.0 To: linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org CC: Vivek Goyal , Haren Myneni , kexec@lists.infradead.org, "Luck, Tony" , "Yu, Fenghua" Subject: [PATCH v2 7/7] ia64, kdump: Short path to freeze CPUs References: <4A39E247.4030908@jp.fujitsu.com> <4A5595F3.2050609@jp.fujitsu.com> In-Reply-To: <4A5595F3.2050609@jp.fujitsu.com> Content-Type: text/plain; charset=ISO-2022-JP Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4291 Lines: 111 Setting monarch_cpu = -1 to let slaves frozen might not work, because there might be slaves being late, not entered the rendezvous yet. Such slaves might be caught in while (monarch_cpu == -1) loop. Use kdump_in_progress instead of monarch_cpus to break INIT rendezvous and let all slaves enter DIE_INIT_SLAVE_LEAVE smoothly. And monarch no longer need to manage rendezvous if once kdump_in_progress is set, catch the monarch in DIE_INIT_MONARCH_ENTER then. Signed-off-by: Hidetoshi Seto Cc: Vivek Goyal Cc: Haren Myneni Cc: kexec@lists.infradead.org --- arch/ia64/kernel/crash.c | 15 ++++++--------- arch/ia64/kernel/mca.c | 15 +++++++++++++-- 2 files changed, 19 insertions(+), 11 deletions(-) diff --git a/arch/ia64/kernel/crash.c b/arch/ia64/kernel/crash.c index 0995fdc..6631a9d 100644 --- a/arch/ia64/kernel/crash.c +++ b/arch/ia64/kernel/crash.c @@ -127,14 +127,13 @@ machine_crash_shutdown(struct pt_regs *pt) * If an INIT is asserted here: * - All receivers might be slaves, since some of cpus could already * be frozen and INIT might be masked on monarch. In this case, - * all slaves will park in while (monarch_cpu == -1) loop before - * DIE_INIT_SLAVE_ENTER that for waiting monarch enters. - * => TBD: freeze all slaves + * all slaves will be frozen soon since kdump_in_progress will let + * them into DIE_INIT_SLAVE_LEAVE. * - One might be a monarch, but INIT rendezvous will fail since * at least this cpu already have INIT masked so it never join * to the rendezvous. In this case, all slaves and monarch will - * be frozen after timeout of the INIT rendezvous. - * => TBD: freeze them without waiting timeout + * be frozen soon with no wait since the INIT rendezvous is skipped + * by kdump_in_progress. */ kdump_smp_send_stop(); /* not all cpu response to IPI, send INIT to freeze them */ @@ -187,6 +186,7 @@ kdump_init_notifier(struct notifier_block *self, unsigned long val, void *data) break; /* fall through */ case DIE_INIT_SLAVE_LEAVE: + case DIE_INIT_MONARCH_ENTER: case DIE_MCA_RENDZVOUS_LEAVE: unw_init_running(kdump_cpu_freeze, NULL); break; @@ -217,7 +217,6 @@ kdump_init_notifier(struct notifier_block *self, unsigned long val, void *data) if (kdump_on_init && (nd->sos->rv_rc != 1)) { if (atomic_inc_return(&kdump_in_progress) != 1) kdump_freeze_monarch = 1; - *(nd->monarch_cpu) = -1; } break; case DIE_INIT_MONARCH_LEAVE: @@ -228,10 +227,8 @@ kdump_init_notifier(struct notifier_block *self, unsigned long val, void *data) case DIE_MCA_MONARCH_LEAVE: /* *(nd->data) indicate if MCA is recoverable */ if (kdump_on_fatal_mca && !(*(nd->data))) { - if (atomic_inc_return(&kdump_in_progress) == 1) { - *(nd->monarch_cpu) = -1; + if (atomic_inc_return(&kdump_in_progress) == 1) machine_kdump_on_init(); - } /* We got fatal MCA while kdump!? No way!! */ } break; diff --git a/arch/ia64/kernel/mca.c b/arch/ia64/kernel/mca.c index 7b30d21..d2877a7 100644 --- a/arch/ia64/kernel/mca.c +++ b/arch/ia64/kernel/mca.c @@ -1682,14 +1682,25 @@ ia64_init_handler(struct pt_regs *regs, struct switch_stack *sw, if (!sos->monarch) { ia64_mc_info.imi_rendez_checkin[cpu] = IA64_MCA_RENDEZ_CHECKIN_INIT; + +#ifdef CONFIG_KEXEC + while (monarch_cpu == -1 && !atomic_read(&kdump_in_progress)) + udelay(1000); +#else while (monarch_cpu == -1) - cpu_relax(); /* spin until monarch enters */ + cpu_relax(); /* spin until monarch enters */ +#endif NOTIFY_INIT(DIE_INIT_SLAVE_ENTER, regs, (long)&nd, 1); NOTIFY_INIT(DIE_INIT_SLAVE_PROCESS, regs, (long)&nd, 1); +#ifdef CONFIG_KEXEC + while (monarch_cpu != -1 && !atomic_read(&kdump_in_progress)) + udelay(1000); +#else while (monarch_cpu != -1) - cpu_relax(); /* spin until monarch leaves */ + cpu_relax(); /* spin until monarch leaves */ +#endif NOTIFY_INIT(DIE_INIT_SLAVE_LEAVE, regs, (long)&nd, 1); -- 1.6.0 -- 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/