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2.6.2-rc2-mm2 CPU Hotplug: i386 support

PATCH In review Rusty Russell 1 participant 1 message Jan 31, 2004

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Rusty Russell

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PATCH 4/4 2.6.2-rc2-mm2 CPU Hotplug: i386 support

This is the i386 portion: we've basically been using it to stress the core code, unlike the PPC64 which actually has hotplug CPUs (but this is better, because we can plug/unplug REALLY fast to find races).

As such, it's a curiousity, and a little rough (doesn't allow boot CPU to go down, for example). But great for playing with the code.

The main change is that the IPI-sending types of code have been changed to use a cpumask_t rather than a count, since cpus may appear and vanish and we don't want to hold a lock.

Name: Hotplug CPU Patch: i386 support: -mm Version
Author: Matt Fleming, Zwane Mwaikambo, Dipankar Sarma, Vatsa Vaddagiri
Status: Experimental
Depends: Hotcpu-mm/hotcpu-with-kthread-simple-mm.patch.gz
Depends: Hotcpu/hotcpu-cpu_active_map.patch.gz
Version: -mm

D: i386 hotplug CPU support, as modified by Dipankar and Vatsa.

arch/i386/Kconfig +9 -0
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .26398-linux-2.6.2-rc2-mm2/arch/i386/Kconfig .26398-linux-2.6.2-rc2-mm2.updated/arch/i386/Kconfig
@@ -1229,6 +1229,15 @@ config HOTPLUG
 	  agent" (/sbin/hotplug) to load modules and set up software needed
 	  to use devices as you hotplug them.
 
+config HOTPLUG_CPU
+	bool "Support for hot-pluggable CPUs (EXPERIMENTAL)"
+	depends on SMP && HOTPLUG && EXPERIMENTAL
+	---help---
+	  Say Y here to experiment with turning CPUs off and on.  CPUs
+	  can be controlled through /sys/devices/system/cpu.
+
+	  Say N.
+
 source "drivers/pcmcia/Kconfig"
 
 source "drivers/pci/hotplug/Kconfig"
arch/i386/kernel/irq.c +69 -0

93 lines not on this page · raw message

arch/i386/kernel/process.c +58 -0

82 lines not on this page · raw message

arch/i386/kernel/smp.c +52 -24

148 lines not on this page · raw message

arch/i386/kernel/smpboot.c +109 -2

164 lines not on this page · raw message

include/asm-i386/cpu.h +2 -0
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .26398-linux-2.6.2-rc2-mm2/include/asm-i386/cpu.h .26398-linux-2.6.2-rc2-mm2.updated/include/asm-i386/cpu.h
@@ -4,6 +4,7 @@
 #include <linux/device.h>
 #include <linux/cpu.h>
 #include <linux/topology.h>
+#include <linux/percpu.h>
 
 #include <asm/node.h>
 

@@ -23,4 +24,5 @@ static inline int arch_register_cpu(int 
 	return register_cpu(&cpu_devices[num].cpu, num, parent);
 }
 
+DECLARE_PER_CPU(int, cpu_state);
 #endif /* _ASM_I386_CPU_H_ */
include/asm-i386/smp.h +6 -0
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .26398-linux-2.6.2-rc2-mm2/include/asm-i386/smp.h .26398-linux-2.6.2-rc2-mm2.updated/include/asm-i386/smp.h
@@ -9,6 +9,7 @@
 #include <linux/kernel.h>
 #include <linux/threads.h>
 #include <linux/cpumask.h>
+#include <linux/spinlock.h>
 #endif
 
 #ifdef CONFIG_X86_LOCAL_APIC

@@ -52,6 +53,7 @@ extern void zap_low_mappings (void);
  */
 #define smp_processor_id() (current_thread_info()->cpu)
 
+extern spinlock_t call_lock;
 extern cpumask_t cpu_callout_map;
 #define cpu_possible_map cpu_callout_map
 

@@ -84,6 +86,10 @@ static __inline int logical_smp_processo
 }
 
 #endif
+
+extern int __cpu_disable(void);
+extern void __cpu_die(unsigned int cpu);
+
 #endif /* !__ASSEMBLY__ */
 
 #define NO_PROC_ID		0xFF		/* No processor magic marker */

--
Anyone who quotes me in their sig is an idiot. -- Rusty Russell.