Attachment 153977 Details for Bug 236929 – PATCH 3 (revised again): Fix cpu_hotplug_lock deadly embrace

[patch] PATCH 3 (revised again): Fix cpu_hotplug_lock deadly embrace

linux-2.6.9-xen-hotplug-suspend-resume3.patch (text/plain), 4.61 KB, created by Chris Lalancette on 2007-05-02 19:17:34 UTC

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Creator: Chris Lalancette

Created: 2007-05-02 19:17:34 UTC

Size: 4.61 KB

patch

obsolete

>diff -urp linux-2.6.9.hotplug-cleanup/drivers/xen/core/cpu_hotplug.c linux-2.6.9/drivers/xen/core/cpu_hotplug.c
>--- linux-2.6.9.hotplug-cleanup/drivers/xen/core/cpu_hotplug.c	2007-04-30 10:02:06.000000000 -0400
>+++ linux-2.6.9/drivers/xen/core/cpu_hotplug.c	2007-04-30 10:03:43.000000000 -0400
>@@ -122,30 +122,19 @@ arch_initcall(setup_vcpu_hotplug_event);
> 
> int smp_suspend(void)
> {
>-	int i, err;
>-
>-	lock_cpu_hotplug();
>-
>-	/*
>-	 * Take all other CPUs offline. We hold the hotplug mutex to
>-	 * avoid other processes bringing up CPUs under our feet.
>-	 */
>-	while (num_online_cpus() > 1) {
>-		unlock_cpu_hotplug();
>-		for_each_online_cpu(i) {
>-			if (i == 0)
>-				continue;
>-			err = cpu_down(i);
>-			if (err) {
>-				printk(KERN_CRIT "Failed to take all CPUs "
>-				       "down: %d.\n", err);
>-				for_each_possible_cpu(i)
>-					vcpu_hotplug(i);
>-				return err;
>-			}
>-		}
>-		lock_cpu_hotplug();
>-	}
>+	int cpu, err;
>+	for_each_online_cpu(cpu) {
>+		if (cpu == 0)
>+			continue;
>+		err = cpu_down(cpu);
>+		if (err) {
>+			printk(KERN_CRIT "Failed to take all CPUs "
>+			       "down: %d.\n", err);
>+			for_each_possible_cpu(cpu)
>+				vcpu_hotplug(cpu);
>+			return err;
>+ 		}
>+ 	}
> 
> 	return 0;
> }
>@@ -155,11 +144,6 @@ void smp_resume(void)
> 	int cpu;
> 
> 	for_each_possible_cpu(cpu)
>-		cpu_initialize_context(cpu);
>-
>-	unlock_cpu_hotplug();
>-
>-	for_each_possible_cpu(cpu)
> 		vcpu_hotplug(cpu);
> }
> 
>diff -urp linux-2.6.9.hotplug-cleanup/drivers/xen/core/reboot.c linux-2.6.9/drivers/xen/core/reboot.c
>--- linux-2.6.9.hotplug-cleanup/drivers/xen/core/reboot.c	2007-04-30 09:54:59.000000000 -0400
>+++ linux-2.6.9/drivers/xen/core/reboot.c	2007-04-30 10:03:43.000000000 -0400
>@@ -118,6 +118,10 @@ static void post_suspend(void)
> 	extern unsigned long *pfn_to_mfn_frame_list_list;
> 	extern unsigned long *pfn_to_mfn_frame_list[];
> 
>+#ifdef CONFIG_SMP
>+	cpu_initialized_map = cpu_online_map;
>+#endif
>+
> 	set_fixmap(FIX_SHARED_INFO, xen_start_info->shared_info);
> 
> 	HYPERVISOR_shared_info = (shared_info_t *)fix_to_virt(FIX_SHARED_INFO);
>diff -urp linux-2.6.9.hotplug-cleanup/drivers/xen/core/smpboot.c linux-2.6.9/drivers/xen/core/smpboot.c
>--- linux-2.6.9.hotplug-cleanup/drivers/xen/core/smpboot.c	2007-04-30 10:02:06.000000000 -0400
>+++ linux-2.6.9/drivers/xen/core/smpboot.c	2007-04-30 10:03:43.000000000 -0400
>@@ -45,8 +45,6 @@ extern void cpu_idle(void);
> 
> extern void fixup_irqs(cpumask_t);
> 
>-extern cpumask_t cpu_initialized;
>-
> /* Number of siblings per CPU package */
> int smp_num_siblings = 1;
> int phys_proc_id[NR_CPUS]; /* Package ID of each logical CPU */
>@@ -58,6 +56,7 @@ cpumask_t cpu_online_map;
> EXPORT_SYMBOL(cpu_online_map);
> cpumask_t cpu_possible_map;
> EXPORT_SYMBOL(cpu_possible_map);
>+cpumask_t cpu_initialized_map;
> 
> struct cpuinfo_x86 cpu_data[NR_CPUS] __cacheline_aligned;
> EXPORT_SYMBOL(cpu_data);
>@@ -173,7 +172,7 @@ static void cpu_bringup_and_idle(void)
> 	cpu_idle();
> }
> 
>-void cpu_initialize_context(unsigned int cpu)
>+static void cpu_initialize_context(unsigned int cpu)
> {
> 	vcpu_guest_context_t ctxt;
> 	struct task_struct *idle = idle_task(cpu);
>@@ -183,7 +182,7 @@ void cpu_initialize_context(unsigned int
> 	struct Xgt_desc_struct *gdt_descr = &cpu_gdt_descr[cpu];
> #endif
> 
>-	if (cpu == 0)
>+	if (cpu_test_and_set(cpu, cpu_initialized_map))
> 		return;
> 
> 	memset(&ctxt, 0, sizeof(ctxt));
>@@ -271,6 +270,8 @@ void __init smp_prepare_cpus(unsigned in
> 
> 	xen_smp_intr_init(0);
> 
>+	cpu_initialized_map = cpumask_of_cpu(0);
>+
> 	/* Restrict the possible_map according to max_cpus. */
> 	while ((num_possible_cpus() > 1) && (num_possible_cpus() > max_cpus)) {
> 		for (cpu = NR_CPUS-1; !cpu_isset(cpu, cpu_possible_map); cpu--)
>@@ -432,6 +433,8 @@ int __devinit __cpu_up(unsigned int cpu)
> 	if (rc)
> 		return rc;
> 
>+	cpu_initialize_context(cpu);
>+
> #ifdef CONFIG_SMP_ALTERNATIVES
> 	if (num_online_cpus() == 1)
> 		prepare_for_smp();
>diff -urp linux-2.6.9.hotplug-cleanup/include/xen/cpu_hotplug.h linux-2.6.9/include/xen/cpu_hotplug.h
>--- linux-2.6.9.hotplug-cleanup/include/xen/cpu_hotplug.h	2007-04-30 09:54:59.000000000 -0400
>+++ linux-2.6.9/include/xen/cpu_hotplug.h	2007-04-30 10:03:43.000000000 -0400
>@@ -4,14 +4,15 @@
> #include <linux/kernel.h>
> #include <linux/cpumask.h>
> 
>-#if defined(CONFIG_HOTPLUG_CPU)
>-
>-#if defined(CONFIG_X86)
>-void cpu_initialize_context(unsigned int cpu);
>+#if defined(CONFIG_X86) && defined(CONFIG_SMP)
>+extern cpumask_t cpu_initialized_map;
>+#define cpu_set_initialized(cpu) cpu_set(cpu, cpu_initialized_map)
> #else
>-#define cpu_initialize_context(cpu)	((void)0)
>+#define cpu_set_initialized(cpu) ((void)0)
> #endif
> 
>+#if defined(CONFIG_HOTPLUG_CPU)
>+
> int cpu_up_check(unsigned int cpu);
> void init_xenbus_allowed_cpumask(void);
> int smp_suspend(void);

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Attachments on bug 236929: 153275 | 153276 | 153277 | 153278 | 153350 | 153821 | 153881 | 153962 | 153977