From: "Fenghua Yu" <fenghua.yu@intel.com>
To: "Ingo Molnar" <mingo@elte.hu>,
"Thomas Gleixner" <tglx@linutronix.de>,
"H Peter Anvin" <hpa@zytor.com>,
"Linus Torvalds" <torvalds@linux-foundation.org>,
"Andrew Morton" <akpm@linux-foundation.org>,
"Asit K Mallick" <asit.k.mallick@intel.com>,
"Tony Luck" <tony.luck@intel.com>,
"Arjan van de Ven" <arjan.van.de.ven@intel.com>,
"Suresh B Siddha" <suresh.b.siddha@intel.com>,
"Len Brown" <len.brown@intel.com>,
"Randy Dunlap" <rdunlap@xenotime.net>,
"Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>,
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
Peter Zijlstra <peterz@infradead.org>,
"Chen Gong" <gong.chen@linux.intel.com>,
"linux-kernel" <linux-kernel@vger.kernel.org>,
"linux-pm" <linux-pm@vger.kernel.org>, "x86" <x86@kernel.org>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Subject: [PATCH v5 04/12] x86/smpboot.c: Don't offline CPU0 if any irq can not be migrated out of it and remove CPU0 check in smp_callin()
Date: Wed, 11 Jan 2012 09:04:45 -0800 [thread overview]
Message-ID: <1326301493-28760-5-git-send-email-fenghua.yu@intel.com> (raw)
In-Reply-To: <1326301493-28760-1-git-send-email-fenghua.yu@intel.com>
From: Fenghua Yu <fenghua.yu@intel.com>
Don't offline CPU0 if any irq can not be migrated out of it.
Call identify_boot_cpu_online() for CPU0 in smp_callin() and continue to online
CPU0 in native_cpu_up().
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
---
arch/x86/kernel/smpboot.c | 42 +++++++++++++++++++++++++++++++++++-------
1 files changed, 35 insertions(+), 7 deletions(-)
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 66d250c..a3c4be3 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -136,8 +136,8 @@ EXPORT_PER_CPU_SYMBOL(cpu_info);
atomic_t init_deasserted;
/*
- * Report back to the Boot Processor.
- * Running on AP.
+ * Report back to the Boot Processor during boot time or to the caller processor
+ * during CPU online.
*/
static void __cpuinit smp_callin(void)
{
@@ -230,6 +230,13 @@ static void __cpuinit smp_callin(void)
pr_debug("Stack at about %p\n", &cpuid);
/*
+ * This function won't run on the BSP during boot time. It run
+ * on BSP only when BSP is offlined and onlined again.
+ */
+ if (cpuid == 0)
+ identify_boot_cpu_online();
+
+ /*
* This must be done before setting cpu_online_mask
* or calling notify_cpu_starting.
*/
@@ -845,7 +852,7 @@ int __cpuinit native_cpu_up(unsigned int cpu)
pr_debug("++++++++++++++++++++=_---CPU UP %u\n", cpu);
- if (apicid == BAD_APICID || apicid == boot_cpu_physical_apicid ||
+ if (apicid == BAD_APICID ||
!physid_isset(apicid, phys_cpu_present_map) ||
(!x2apic_mode && apicid >= 255)) {
printk(KERN_ERR "%s: bad cpu %d\n", __func__, cpu);
@@ -1291,12 +1298,33 @@ int native_cpu_disable(void)
* Perhaps use cpufreq to drop frequency, but that could go
* into generic code.
*
- * We won't take down the boot processor on i386 due to some
+ * We won't take down the boot processor on x86 if some
* interrupts only being able to be serviced by the BSP.
- * Especially so if we're not using an IOAPIC -zwane
+ * Especially so if we're not using an IOAPIC
*/
- if (cpu == 0)
- return -EBUSY;
+ if (cpu == 0) {
+ int irq;
+ struct irq_desc *desc;
+ struct irq_data *data;
+ struct irq_chip *chip;
+
+ for_each_irq_desc(irq, desc) {
+ raw_spin_lock(&desc->lock);
+ if (!irq_has_action(irq)) {
+ raw_spin_unlock(&desc->lock);
+ continue;
+ }
+
+ data = irq_desc_get_irq_data(desc);
+ chip = irq_data_get_irq_chip(data);
+ if (!chip->irq_set_affinity) {
+ pr_debug("irq%d can't move out of BSP\n", irq);
+ raw_spin_unlock(&desc->lock);
+ return -EBUSY;
+ }
+ raw_spin_unlock(&desc->lock);
+ }
+ }
clear_local_APIC();
--
1.6.0.3
next prev parent reply other threads:[~2012-01-11 17:28 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-11 17:04 [PATCH v5 0/12] x86: Arbitrary CPU hot(un)plug support Fenghua Yu
2012-01-11 17:04 ` [PATCH v5 01/12] Documentations/cpu-hotplug.tx, kernel-parameters.txt: Add x86 CPU0 online/offline feature Fenghua Yu
2012-01-11 17:04 ` [PATCH v5 02/12] x86/Kconfig: Add config switch for CPU0 hotplug Fenghua Yu
2012-01-11 17:04 ` [PATCH v5 03/12] x86/topology.c: Support functions for CPU0 online/offline Fenghua Yu
2012-01-16 17:35 ` Ben Hutchings
2012-01-24 22:31 ` Yu, Fenghua
2012-01-24 22:52 ` Ben Hutchings
2012-01-24 23:00 ` Yu, Fenghua
2012-01-11 17:04 ` Fenghua Yu [this message]
2012-01-11 17:04 ` [PATCH v5 05/12] x86/power/cpu.c: Don't hibernate/suspend if CPU0 is offline Fenghua Yu
2012-01-11 17:04 ` [PATCH v5 06/12] x86/head_64.S: Define start_cpu0 Fenghua Yu
2012-01-11 17:04 ` [PATCH v5 07/12] x86/head_32.S: " Fenghua Yu
2012-01-11 17:04 ` [PATCH v5 08/12] x86/smpboot.c: Wake up CPU0 via NMI instead of INITs Fenghua Yu
2012-01-12 12:31 ` Brian Gerst
2012-01-11 17:04 ` [PATCH v5 09/12] x86/common.c: Init CPU0 data during CPU0 online Fenghua Yu
2012-01-11 17:04 ` [PATCH v5 10/12] x86/mtrr/main.c: Ask the first online CPU to save mtrr Fenghua Yu
2012-01-12 12:33 ` Brian Gerst
2012-01-16 0:07 ` H. Peter Anvin
2012-01-25 17:58 ` Yu, Fenghua
2012-01-25 19:01 ` Yu, Fenghua
2012-01-11 17:04 ` [PATCH v5 11/12] x86/i387.c: Thread xstate is initialized only on CPU0 once Fenghua Yu
2012-01-11 17:04 ` [PATCH v5 12/12] x86/topology.c: debug CPU0 hotplug Fenghua Yu
2012-01-15 15:24 ` Jiang Liu
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