lkml.org 
[lkml]   [2003]   [Feb]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH][2.5][2/5] CPU Hotplug i386 core
 arch/i386/kernel/irq.c     |   18 ++++++++++++
arch/i386/kernel/process.c | 39 ++++++++++++++++++++++++++-
arch/i386/kernel/smp.c | 18 ++++++++++--
arch/i386/kernel/smpboot.c | 63 ++++++++++++++++++++++++++++++++++++++++++---
include/asm-i386/smp.h | 4 ++
5 files changed, 133 insertions(+), 9 deletions(-)

Index: linux-2.5.61-trojan/include/asm-i386/smp.h
===================================================================
RCS file: /build/cvsroot/linux-2.5.61/include/asm-i386/smp.h,v
retrieving revision 1.1.1.1
diff -u -r1.1.1.1 smp.h
--- linux-2.5.61-trojan/include/asm-i386/smp.h 15 Feb 2003 12:32:04 -0000 1.1.1.1
+++ linux-2.5.61-trojan/include/asm-i386/smp.h 15 Feb 2003 19:31:05 -0000
@@ -100,6 +100,10 @@
}

#endif
+
+extern int __cpu_disable(void);
+extern void __cpu_die(unsigned int cpu);
+
#endif /* !__ASSEMBLY__ */

#define NO_PROC_ID 0xFF /* No processor magic marker */
Index: linux-2.5.61-trojan/arch/i386/kernel/irq.c
===================================================================
RCS file: /build/cvsroot/linux-2.5.61/arch/i386/kernel/irq.c,v
retrieving revision 1.1.1.1
diff -u -r1.1.1.1 irq.c
--- linux-2.5.61-trojan/arch/i386/kernel/irq.c 15 Feb 2003 12:32:09 -0000 1.1.1.1
+++ linux-2.5.61-trojan/arch/i386/kernel/irq.c 15 Feb 2003 21:23:09 -0000
@@ -870,6 +870,24 @@
return full_count;
}

+void migrate_irqs_from(unsigned int cpu)
+{
+ unsigned long mask = cpu_online_map & ~(1UL << cpu);
+ unsigned int irq;
+
+ for (irq = 0; irq < NR_IRQS; irq++) {
+ if (!irq_desc[irq].handler->set_affinity)
+ continue;
+
+ irq_affinity[irq] &= mask;
+ if (irq_affinity[irq] == 0) {
+ irq_affinity[irq] = mask;
+ printk(KERN_INFO "dying cpu%d has irq%d affined to it, setting to %lx\n",
+ cpu, irq, mask);
+ }
+ irq_desc[irq].handler->set_affinity(irq, mask);
+ }
+}
#endif

static int prof_cpu_mask_read_proc (char *page, char **start, off_t off,
Index: linux-2.5.61-trojan/arch/i386/kernel/process.c
===================================================================
RCS file: /build/cvsroot/linux-2.5.61/arch/i386/kernel/process.c,v
retrieving revision 1.1.1.1
diff -u -r1.1.1.1 process.c
--- linux-2.5.61-trojan/arch/i386/kernel/process.c 15 Feb 2003 12:32:09 -0000 1.1.1.1
+++ linux-2.5.61-trojan/arch/i386/kernel/process.c 17 Feb 2003 06:47:05 -0000
@@ -36,7 +36,7 @@
#include <linux/mc146818rtc.h>
#include <linux/module.h>
#include <linux/kallsyms.h>
-
+#include <linux/brlock.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/system.h>
@@ -46,6 +46,7 @@
#include <asm/i387.h>
#include <asm/irq.h>
#include <asm/desc.h>
+#include <asm/tlbflush.h>
#ifdef CONFIG_MATH_EMULATION
#include <asm/math_emu.h>
#endif
@@ -80,6 +81,8 @@
hlt_counter--;
}

+DECLARE_PER_CPU(int, cpu_die);
+
/*
* We use this if we don't have any better
* idle routine..
@@ -127,6 +130,36 @@
}
}

+#if defined(CONFIG_HOTPLUG) && defined(CONFIG_SMP)
+static inline void maybe_play_dead(void)
+{
+ if (unlikely(__get_cpu_var(cpu_die))) {
+ printk("Cpu %u Dust Dust Dust\n", smp_processor_id());
+ /* Ack it */
+ __get_cpu_var(cpu_die) = 2;
+
+ /* Death loop */
+ local_irq_disable();
+ while (__get_cpu_var(cpu_die))
+ cpu_relax();
+ local_irq_enable();
+
+ /* Now, we missed any cache flush IPIs, so be safe. */
+ local_flush_tlb();
+
+ /* Ack it by setting online bit */
+ br_write_lock_irq(BR_CPU_LOCK);
+ set_bit(smp_processor_id(), &cpu_online_map);
+ br_write_unlock_irq(BR_CPU_LOCK);
+ printk("Cpu %u arisen\n", smp_processor_id());
+ }
+}
+#else
+static inline void maybe_play_dead(void)
+{
+}
+#endif /*CONFIG_HOTPLUG*/
+
/*
* The idle thread. There's no useful work to be
* done, so just try to conserve power and have a
@@ -141,8 +174,10 @@
if (!idle)
idle = default_idle;
irq_stat[smp_processor_id()].idle_timestamp = jiffies;
- while (!need_resched())
+ while (!need_resched()) {
+ maybe_play_dead();
idle();
+ }
schedule();
}
}
Index: linux-2.5.61-trojan/arch/i386/kernel/smp.c
===================================================================
RCS file: /build/cvsroot/linux-2.5.61/arch/i386/kernel/smp.c,v
retrieving revision 1.1.1.1
diff -u -r1.1.1.1 smp.c
--- linux-2.5.61-trojan/arch/i386/kernel/smp.c 15 Feb 2003 12:32:09 -0000 1.1.1.1
+++ linux-2.5.61-trojan/arch/i386/kernel/smp.c 15 Feb 2003 19:31:05 -0000
@@ -19,6 +19,7 @@
#include <linux/mc146818rtc.h>
#include <linux/cache.h>
#include <linux/interrupt.h>
+#include <linux/brlock.h>

#include <asm/mtrr.h>
#include <asm/pgalloc.h>
@@ -350,13 +351,18 @@
*/
if (!cpumask)
BUG();
- if ((cpumask & cpu_online_map) != cpumask)
+ if ((cpumask & cpu_callout_map) != cpumask)
BUG();
if (cpumask & (1 << smp_processor_id()))
BUG();
if (!mm)
BUG();

+ /* CPUs might have gone offline: don't worry about them. */
+ cpumask &= cpu_online_map;
+ if (!cpumask)
+ return;
+
/*
* i'm not happy about this global shared spinlock in the
* MM hot path, but we'll see how contended it is.
@@ -515,10 +521,15 @@
*/
{
struct call_data_struct data;
- int cpus = num_online_cpus()-1;
+ int cpus;

- if (!cpus)
+ br_read_lock(BR_CPU_LOCK);
+ cpus = num_online_cpus()-1;
+
+ if (!cpus) {
+ br_read_unlock(BR_CPU_LOCK);
return 0;
+ }

data.func = func;
data.info = info;
@@ -542,6 +553,7 @@
barrier();
spin_unlock(&call_lock);

+ br_read_unlock(BR_CPU_LOCK);
return 0;
}

Index: linux-2.5.61-trojan/arch/i386/kernel/smpboot.c
===================================================================
RCS file: /build/cvsroot/linux-2.5.61/arch/i386/kernel/smpboot.c,v
retrieving revision 1.1.1.1
diff -u -r1.1.1.1 smpboot.c
--- linux-2.5.61-trojan/arch/i386/kernel/smpboot.c 15 Feb 2003 12:32:09 -0000 1.1.1.1
+++ linux-2.5.61-trojan/arch/i386/kernel/smpboot.c 16 Feb 2003 19:56:16 -0000
@@ -45,6 +45,8 @@

#include <linux/delay.h>
#include <linux/mc146818rtc.h>
+#include <linux/brlock.h>
+#include <linux/percpu.h>
#include <asm/pgalloc.h>
#include <asm/tlbflush.h>
#include <asm/desc.h>
@@ -64,9 +66,10 @@
/* Bitmask of currently online CPUs */
unsigned long cpu_online_map;

-static volatile unsigned long cpu_callin_map;
+/* Initialize, although master cpu never calls in */
+static volatile unsigned long cpu_callin_map = 1;
volatile unsigned long cpu_callout_map;
-static unsigned long smp_commenced_mask;
+static unsigned long smp_commenced_mask = 1;

/* Per CPU bogomips and other parameters */
struct cpuinfo_x86 cpu_data[NR_CPUS] __cacheline_aligned;
@@ -456,7 +461,9 @@
* the local TLBs too.
*/
local_flush_tlb();
+ br_write_lock_irq(BR_CPU_LOCK);
set_bit(smp_processor_id(), &cpu_online_map);
+ br_write_unlock_irq(BR_CPU_LOCK);
wmb();
return cpu_idle();
}
@@ -1130,10 +1136,11 @@
set_bit(smp_processor_id(), &cpu_callout_map);
}

+DEFINE_PER_CPU(int, cpu_die) = { 0 };
+
int __devinit __cpu_up(unsigned int cpu)
{
- /* This only works at boot for x86. See "rewrite" above. */
- if (test_bit(cpu, &smp_commenced_mask)) {
+ if (test_bit(cpu, &smp_commenced_mask) && cpu_online(cpu)) {
local_irq_enable();
return -ENOSYS;
}
@@ -1144,12 +1151,61 @@
return -EIO;
}

+ /* Already up, and in maybe_play_dead now? */
+ if (test_bit(cpu, &smp_commenced_mask)) {
+ per_cpu(cpu_die, cpu) = 0;
+ wmb();
+ wake_idle_cpu(cpu);
+ while (!cpu_online(cpu))
+ yield();
+ printk("Cpu %u says it's online\n", cpu);
+ return 0;
+ }
+
local_irq_enable();
/* Unleash the CPU! */
set_bit(cpu, &smp_commenced_mask);
while (!test_bit(cpu, &cpu_online_map))
mb();
return 0;
+}
+
+int __cpu_disable(void)
+{
+ br_write_lock_irq(BR_CPU_LOCK);
+ cpu_online_map &= ~(1UL << smp_processor_id());
+ br_write_unlock_irq(BR_CPU_LOCK);
+
+ printk("Disabled cpu %u\n", smp_processor_id());
+ return 0;
+}
+
+extern void migrate_irqs_from(unsigned int cpu);
+
+void __cpu_die(unsigned int cpu)
+{
+ unsigned int start;
+
+ /* Final threads can take some time to actually clean up */
+ while (!idle_cpu(cpu))
+ yield();
+
+ /* The irq affinity code is generic, now we just need a kernel/irq.c
+ * notice that we don't add it again on cpu_up, this is to avoid
+ * botching up current affinity and it would have to be moved later
+ * since we can't do this at boot hmm FIXME... -Zwane */
+ migrate_irqs_from(cpu);
+
+ per_cpu(cpu_die, cpu) = 1;
+ wmb();
+ for (start = jiffies; time_before(jiffies, start + HZ); ) {
+ wake_idle_cpu(cpu);
+ /* They ack this in maybe_play_dead by incrementing it. */
+ if (per_cpu(cpu_die, cpu) == 2)
+ return;
+ yield();
+ }
+ printk(KERN_ERR "CPU %u didn't die...\n", cpu);
}

void __init smp_cpus_done(unsigned int max_cpus)
-
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/
\
 
 \ /
  Last update: 2005-03-22 13:33    [W:0.041 / U:22.756 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site