ia64 specific implementation of cpu bulk removal. Add the config and make
__cpu_die/__cpu_disable work with cpumask_t.
Signed-off-by: Ashok Raj <[email protected]>
Signed-off-by: Shaohua Li <[email protected]>
---
linux-2.6.17-rc3-root/arch/ia64/Kconfig | 11 +
linux-2.6.17-rc3-root/arch/ia64/kernel/irq.c | 38 -----
linux-2.6.17-rc3-root/arch/ia64/kernel/smpboot.c | 172 ++++++++++++++++++-----
linux-2.6.17-rc3-root/arch/ia64/kernel/time.c | 5
4 files changed, 158 insertions(+), 68 deletions(-)
diff -puN arch/ia64/Kconfig~ia64-bulk-cpu-hotplug arch/ia64/Kconfig
--- linux-2.6.17-rc3/arch/ia64/Kconfig~ia64-bulk-cpu-hotplug 2006-05-07 07:46:35.000000000 +0800
+++ linux-2.6.17-rc3-root/arch/ia64/Kconfig 2006-05-07 07:46:35.000000000 +0800
@@ -270,6 +270,17 @@ config HOTPLUG_CPU
can be controlled through /sys/devices/system/cpu/cpu#.
Say N if you want to disable CPU hotplug.
+config BULK_CPU_REMOVE
+ bool "Support for bulk removal of CPUs (EXPERIMENTAL)"
+ depends on HOTPLUG_CPU && EXPERIMENTAL
+ help
+ Say Y if need the ability to remove more than one cpu during cpu
+ removal. Current mechanisms may be in-efficient when a NUMA
+ node is being removed, which would involve removing one cpu at a
+ time. This will let interrupts, timers and processes to be bound
+ to a CPU that might be removed right after the current cpu is
+ being offlined.
+
config SCHED_SMT
bool "SMT scheduler support"
depends on SMP
diff -puN arch/ia64/kernel/irq.c~ia64-bulk-cpu-hotplug arch/ia64/kernel/irq.c
--- linux-2.6.17-rc3/arch/ia64/kernel/irq.c~ia64-bulk-cpu-hotplug 2006-05-07 07:46:35.000000000 +0800
+++ linux-2.6.17-rc3-root/arch/ia64/kernel/irq.c 2006-05-07 07:46:35.000000000 +0800
@@ -114,7 +114,7 @@ unsigned int vectors_in_migration[NR_IRQ
* Since cpu_online_map is already updated, we just need to check for
* affinity that has zeros
*/
-static void migrate_irqs(void)
+void ia64_migrate_irqs(void)
{
cpumask_t mask;
irq_desc_t *desc;
@@ -159,34 +159,9 @@ static void migrate_irqs(void)
}
}
-void fixup_irqs(void)
+void ia64_fixup_irqs(void)
{
unsigned int irq;
- extern void ia64_process_pending_intr(void);
- extern void ia64_disable_timer(void);
- extern volatile int time_keeper_id;
-
- ia64_disable_timer();
-
- /*
- * Find a new timesync master
- */
- if (smp_processor_id() == time_keeper_id) {
- time_keeper_id = first_cpu(cpu_online_map);
- printk ("CPU %d is now promoted to time-keeper master\n", time_keeper_id);
- }
-
- /*
- * Phase 1: Locate irq's bound to this cpu and
- * relocate them for cpu removal.
- */
- migrate_irqs();
-
- /*
- * Phase 2: Perform interrupt processing for all entries reported in
- * local APIC.
- */
- ia64_process_pending_intr();
/*
* Phase 3: Now handle any interrupts not captured in local APIC.
@@ -199,14 +174,5 @@ void fixup_irqs(void)
__do_IRQ(irq, NULL);
}
}
-
- /*
- * Now let processor die. We do irq disable and max_xtp() to
- * ensure there is no more interrupts routed to this processor.
- * But the local timer interrupt can have 1 pending which we
- * take care in timer_interrupt().
- */
- max_xtp();
- local_irq_disable();
}
#endif
diff -puN arch/ia64/kernel/smpboot.c~ia64-bulk-cpu-hotplug arch/ia64/kernel/smpboot.c
--- linux-2.6.17-rc3/arch/ia64/kernel/smpboot.c~ia64-bulk-cpu-hotplug 2006-05-07 07:46:35.000000000 +0800
+++ linux-2.6.17-rc3-root/arch/ia64/kernel/smpboot.c 2006-05-07 07:46:35.000000000 +0800
@@ -639,24 +639,27 @@ clear_cpu_sibling_map(int cpu)
}
static void
-remove_siblinginfo(int cpu)
+remove_siblinginfo(cpumask_t remove_mask)
{
int last = 0;
+ int cpu;
- if (cpu_data(cpu)->threads_per_core == 1 &&
- cpu_data(cpu)->cores_per_socket == 1) {
- cpu_clear(cpu, cpu_core_map[cpu]);
- cpu_clear(cpu, cpu_sibling_map[cpu]);
- return;
- }
+ for_each_cpu_mask(cpu, remove_mask) {
+ if (cpu_data(cpu)->threads_per_core == 1 &&
+ cpu_data(cpu)->cores_per_socket == 1) {
+ cpu_clear(cpu, cpu_core_map[cpu]);
+ cpu_clear(cpu, cpu_sibling_map[cpu]);
+ continue;
+ }
- last = (cpus_weight(cpu_core_map[cpu]) == 1 ? 1 : 0);
+ last = (cpus_weight(cpu_core_map[cpu]) == 1 ? 1 : 0);
- /* remove it from all sibling map's */
- clear_cpu_sibling_map(cpu);
+ /* remove it from all sibling map's */
+ clear_cpu_sibling_map(cpu);
+ }
}
-extern void fixup_irqs(void);
+extern void ia64_fixup_irqs(void);
int migrate_platform_irqs(unsigned int cpu)
{
@@ -699,49 +702,154 @@ int migrate_platform_irqs(unsigned int c
}
/* must be called with cpucontrol mutex held */
+static cpumask_t cpu_dead_mask = CPU_MASK_NONE;
+static cpumask_t cpu_dead_error_mask = CPU_MASK_NONE;
+static atomic_t disable_cpu_start = ATOMIC_INIT(0); /* 1:start, 2:error */
int __cpu_disable(cpumask_t remove_mask)
{
int cpu = smp_processor_id();
+ int master = 0;
+ extern void ia64_disable_timer(void);
+ extern void ia64_enable_timer(void);
+ extern void ia64_process_pending_intr(void);
+ extern void ia64_migrate_irqs(void);
+ extern volatile int time_keeper_id;
+
+ /* are we the master cpu? */
+ if (first_cpu(remove_mask) == cpu)
+ master = 1;
+
+ ia64_disable_timer();
+ if (master) {
+ int ret = 0, cpu_tmp;
+ cpumask_t temp_online_map, old_online_map;
+
+ /*
+ * dont permit boot processor for now
+ */
+ if (cpu_isset(0, remove_mask) && !bsp_remove_ok) {
+ printk ("Your platform does not support removal of BSP\n");
+ /* let slave report the error */
+ atomic_set(&disable_cpu_start, 2);
+ smp_wmb(); /* set error first */
+ cpu_set(cpu, cpu_dead_error_mask);
+ while (!cpus_equal(cpu_dead_error_mask, remove_mask))
+ cpu_relax();
+ atomic_set(&disable_cpu_start, 0);
+ cpus_clear(cpu_dead_error_mask);
+ ia64_enable_timer();
+ return -EBUSY;
+ }
- BUG_ON(cpus_weight(remove_mask) != 1);
+ old_online_map = cpu_online_map;
+ cpus_andnot(temp_online_map, cpu_online_map, remove_mask);
+ cpu_online_map = temp_online_map;
+ /*
+ * Find a new timesync master
+ */
+ if (cpu_isset(time_keeper_id, remove_mask)) {
+ time_keeper_id = first_cpu(cpu_online_map);
+ printk ("CPU %d is now promoted to time-keeper master\n",
+ time_keeper_id);
+ }
+
+ /*
+ * Check if platform irq's can be migrated
+ */
+ for_each_cpu_mask(cpu_tmp, remove_mask) {
+ if ((ret = migrate_platform_irqs(cpu_tmp)))
+ break;
+ }
+ if (ret) {
+ cpu_online_map = old_online_map;
+ /* let slave report the error */
+ atomic_set(&disable_cpu_start, 2);
+ smp_wmb(); /* set error first */
+ cpu_set(cpu, cpu_dead_error_mask);
+ while (!cpus_equal(cpu_dead_error_mask, remove_mask))
+ cpu_relax();
+ atomic_set(&disable_cpu_start, 0);
+ cpus_clear(cpu_dead_error_mask);
+ ia64_enable_timer();
+ return -EBUSY;
+ }
+ /*
+ * Phase I: IRQ migration: migrate irqs to eligible online cpus
+ */
+ ia64_migrate_irqs();
+
+ smp_mb();
+ /* Let the party begin */
+ atomic_set(&disable_cpu_start, 1);
+ } else {
+ while (atomic_read(&disable_cpu_start) == 0)
+ cpu_relax();
+ if (atomic_read(&disable_cpu_start) == 2) {
+ ia64_enable_timer();
+ cpu_set(cpu, cpu_dead_error_mask);
+ return -EBUSY;
+ }
+ }
/*
- * dont permit boot processor for now
+ * Phase II: IRQ Migration: process any local pending interrupts
+ * that were queued up.
*/
- if (cpu == 0 && !bsp_remove_ok) {
- printk ("Your platform does not support removal of BSP\n");
- return (-EBUSY);
- }
+ ia64_process_pending_intr();
- cpu_clear(cpu, cpu_online_map);
+ /*
+ * Now let processor die. We do irq disable and max_xtp() to
+ * ensure there is no more interrupts routed to this processor.
+ * But the local timer interrupt can have 1 pending which we
+ * take care in timer_interrupt().
+ */
+ max_xtp();
+ local_irq_disable();
- if (migrate_platform_irqs(cpu)) {
- cpu_set(cpu, cpu_online_map);
- return (-EBUSY);
- }
+ cpu_clear(cpu, cpu_callin_map);
+ cpu_clear(cpu, cpu_online_map);
+ smp_mb();
+ cpu_set(cpu, cpu_dead_mask);
+ if (!master)
+ return 0;
+ /* master does cleanup */
+ while (!cpus_equal(cpu_dead_mask, remove_mask))
+ cpu_relax();
+
+ remove_siblinginfo(remove_mask);
- remove_siblinginfo(cpu);
- cpu_clear(cpu, cpu_online_map);
- fixup_irqs();
+ /*
+ * Phase III: irq migration.
+ */
+ ia64_fixup_irqs();
local_flush_tlb_all();
- cpu_clear(cpu, cpu_callin_map);
+ cpus_clear(cpu_dead_mask);
+ atomic_set(&disable_cpu_start, 0);
return 0;
}
void __cpu_die(cpumask_t remove_mask)
{
unsigned int i;
- int cpu = first_cpu(remove_mask);
+ int cpu;
for (i = 0; i < 100; i++) {
/* They ack this in play_dead by setting CPU_DEAD */
- if (per_cpu(cpu_state, cpu) == CPU_DEAD)
- {
- printk ("CPU %d is now offline\n", cpu);
- return;
+ for_each_cpu_mask(cpu, remove_mask) {
+ if (per_cpu(cpu_state, cpu) == CPU_DEAD) {
+ printk ("CPU %d is now offline\n", cpu);
+ cpu_clear(cpu, remove_mask);
+ }
}
+ if (cpus_empty(remove_mask))
+ break;
+
msleep(100);
}
- printk(KERN_ERR "CPU %u didn't die...\n", cpu);
+
+ if (!cpus_empty(remove_mask)) {
+ for_each_cpu_mask(cpu, remove_mask)
+ printk(KERN_ERR "CPU %u didn't die...\n", cpu);
+ }
}
#else /* !CONFIG_HOTPLUG_CPU */
int __cpu_disable(cpumask_t remove_mask)
diff -puN arch/ia64/kernel/time.c~ia64-bulk-cpu-hotplug arch/ia64/kernel/time.c
--- linux-2.6.17-rc3/arch/ia64/kernel/time.c~ia64-bulk-cpu-hotplug 2006-05-07 07:46:35.000000000 +0800
+++ linux-2.6.17-rc3-root/arch/ia64/kernel/time.c 2006-05-07 07:46:35.000000000 +0800
@@ -241,6 +241,11 @@ void __devinit ia64_disable_timer(void)
ia64_set_itv(1 << 16);
}
+void __devinit ia64_enable_timer(void)
+{
+ ia64_set_itv(IA64_TIMER_VECTOR);
+}
+
void __init
time_init (void)
{
_
-
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