From 0cced40e7c58b1105aef3ca446da7b158a18a9a6 Mon Sep 17 00:00:00 2001 From: Hidetoshi Seto <[seto.hidetoshi@jp.fujitsu.com]> Date: Thu, 6 Aug 2009 14:51:58 -0700 Subject: [IA64] kdump: Short path to freeze CPUs 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 Acked-by: Fenghua Yu Signed-off-by: Tony Luck --- arch/ia64/kernel/crash.c | 15 ++++++--------- arch/ia64/kernel/mca.c | 15 +++++++++++++-- 2 files changed, 19 insertions(+), 11 deletions(-) (limited to 'arch/ia64') diff --git a/arch/ia64/kernel/crash.c b/arch/ia64/kernel/crash.c index 0995fdc7b29..6631a9dfafd 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 7b30d21c519..d2877a7bfe2 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); -- cgit v1.2.3