cpu_mask_t

PATCH New Rusty Russell 1 participant 1 message Jul 10, 2002

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Rusty Russell

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2002-07-10 08:29 UTC #0 lore raw

PATCH 1/1 cpu_mask_t

This fixes the last of my cpu_online_map damage, completing the abstraction.

Please apply,
Rusty.

Name: CPU mask patch
Author: Rusty Russell
Status: Trivial

D: This patch adds a cpu_mask_t for easy future expansion of cpu masks,
D: and an easy "migrate_to_cpu()" call for simple in-kernel affinity. It
D: also changes any_online_cpu to return NR_CPUS on failure, like
D: find_first_bit.

include/linux/init_task.h +1 -1

diff -urN -I $.*$ --exclude TAGS -X /home/rusty/current-dontdiff --minimal linux-2.5.25/include/linux/init_task.h working-2.5.25-cpumask/include/linux/init_task.h
@@ -48,7 +48,7 @@
     prio:		MAX_PRIO-20,					
     static_prio:	MAX_PRIO-20,					
     policy:		SCHED_OTHER,					
-    cpus_allowed:	-1,						
+    cpus_allowed:	CPU_MASK_ALL,					
     mm:			NULL,						
     active_mm:		&init_mm,					
     run_list:		LIST_HEAD_INIT(tsk.run_list),

include/linux/sched.h +12 -5

diff -urN -I $.*$ --exclude TAGS -X /home/rusty/current-dontdiff --minimal linux-2.5.25/include/linux/sched.h working-2.5.25-cpumask/include/linux/sched.h
@@ -20,6 +20,7 @@
 #include <asm/page.h>
 #include <asm/ptrace.h>
 #include <asm/mmu.h>
+#include <asm/current.h>
 
 #include <linux/smp.h>
 #include <linux/sem.h>

@@ -263,7 +264,7 @@
 	unsigned long sleep_timestamp;
 
 	unsigned long policy;
-	unsigned long cpus_allowed;
+	cpu_mask_t cpus_allowed;
 	unsigned int time_slice;
 
 	struct list_head tasks;

@@ -407,9 +408,17 @@
 #define _STK_LIM	(8*1024*1024)
 
 #if CONFIG_SMP
-extern void set_cpus_allowed(task_t *p, unsigned long new_mask);
+extern void set_cpus_allowed(task_t *p, cpu_mask_t new_mask);
+static inline void migrate_to_cpu(unsigned int cpu)
+{
+	cpu_mask_t mask = CPU_MASK_NONE;
+	BUG_ON(!cpu_online(cpu));
+	__set_bit(cpu, (unsigned long *)&mask);
+	set_cpus_allowed(current, mask);
+}
 #else
-# define set_cpus_allowed(p, new_mask) do { } while (0)
+#define set_cpus_allowed(p, new_mask) do { } while (0)
+#define migrate_to_cpu(cpu) do { BUG_ON((cpu) != 0); } while(0)
 #endif
 
 extern void set_user_nice(task_t *p, long nice);

@@ -475,8 +484,6 @@
 /* per-UID process charging. */
 extern struct user_struct * alloc_uid(uid_t);
 extern void free_uid(struct user_struct *);
-
-#include <asm/current.h>
 
 extern unsigned long itimer_ticks;
 extern unsigned long itimer_next;

include/linux/smp.h +5 -2

diff -urN -I $.*$ --exclude TAGS -X /home/rusty/current-dontdiff --minimal linux-2.5.25/include/linux/smp.h working-2.5.25-cpumask/include/linux/smp.h
@@ -86,13 +86,16 @@
 #define smp_call_function(func,info,retry,wait)	({ 0; })
 static inline void smp_send_reschedule(int cpu) { }
 static inline void smp_send_reschedule_all(void) { }
-#define cpu_online_map				1
 #define cpu_online(cpu)				1
 #define num_online_cpus()			1
 #define __per_cpu_data
 #define per_cpu(var, cpu)			var
 #define this_cpu(var)				var
-
+typedef unsigned long cpu_mask_t;
+#define CPU_MASK_ALL 1
+#define CPU_MASK_NONE 0
+#define cpu_online_mask(res,mask) do { *(res) = ((mask) & 1); } while(0)
+#define any_online_cpu(mask) (((mask) & 1) ? 0 : 1)
 #endif /* !SMP */
 
 #define get_cpu()	({ preempt_disable(); smp_processor_id(); })

arch/ppc64/kernel/rtasd.c +2 -3

diff -urN -I $.*$ --exclude TAGS -X /home/rusty/current-dontdiff --minimal linux-2.5.25/arch/ppc64/kernel/rtasd.c working-2.5.25-cpumask/arch/ppc64/kernel/rtasd.c
@@ -221,7 +221,7 @@
 #endif
 
 	cpu = 0;
-	set_cpus_allowed(current, 1UL << cpu_logical_map(cpu));
+	migrate_to_cpu(cpu);
 
 	while(1) {
 		do {

@@ -255,8 +255,7 @@
 			cpu = 0;
 		}
 
-		set_cpus_allowed(current, 1UL << cpu_logical_map(cpu));
-
+		migrate_to_cpu(cpu);
 
 		/* Check all cpus for pending events before sleeping*/
 		if (!first_pass) {

include/asm-i386/smp.h +17 -8

diff -urN -I $.*$ --exclude TAGS -X /home/rusty/current-dontdiff --minimal linux-2.5.25/include/asm-i386/smp.h working-2.5.25-cpumask/include/asm-i386/smp.h
@@ -99,14 +99,6 @@
 	return hweight32(cpu_online_map);
 }
 
-extern inline int any_online_cpu(unsigned int mask)
-{
-	if (mask & cpu_online_map)
-		return __ffs(mask & cpu_online_map);
-
-	return -1;
-}
-
 static __inline int hard_smp_processor_id(void)
 {
 	/* we don't want to mark this access volatile - bad code generation */

@@ -117,6 +109,23 @@
 {
 	/* we don't want to mark this access volatile - bad code generation */
 	return GET_APIC_LOGICAL_ID(*(unsigned long *)(APIC_BASE+APIC_LDR));
+}
+
+/* This has to be bitop capable, so for most archs, an unsigned long */
+typedef unsigned long cpu_mask_t;
+#define CPU_MASK_ALL (~0UL)
+#define CPU_MASK_NONE (0UL)
+
+static inline void cpu_online_mask(cpu_mask_t *res, cpu_mask_t mask)
+{
+	*res = (mask & cpu_online_map);
+}
+
+static inline unsigned int any_online_cpu(cpu_mask_t mask)
+{
+	if (mask & cpu_online_map)
+		return __ffs(mask & cpu_online_map);
+	return NR_CPUS;
 }
 
 #endif /* !__ASSEMBLY__ */

include/asm-ia64/smp.h +12 -2

diff -urN -I $.*$ --exclude TAGS -X /home/rusty/current-dontdiff --minimal linux-2.5.25/include/asm-ia64/smp.h working-2.5.25-cpumask/include/asm-ia64/smp.h
@@ -51,12 +51,22 @@
 	return hweight64(cpu_online_map);
 }
 
-extern inline int any_online_cpu(unsigned int mask)
+/* This has to be bitop capable, so for most archs, an unsigned long */
+typedef unsigned long cpu_mask_t;
+#define CPU_MASK_ALL (~0UL)
+#define CPU_MASK_NONE (0UL)
+
+static inline void cpu_online_mask(cpu_mask_t *res, cpu_mask_t mask)
+{
+	*res = (mask & cpu_online_map);
+}
+
+static inline unsigned int any_online_cpu(cpu_mask_t mask)
 {
 	if (mask & cpu_online_map)
 		return __ffs(mask & cpu_online_map);
 
-	return -1;
+	return NR_CPUS;
 }
 
 /*

include/asm-ppc/smp.h +11 -2

diff -urN -I $.*$ --exclude TAGS -X /home/rusty/current-dontdiff --minimal linux-2.5.25/include/asm-ppc/smp.h working-2.5.25-cpumask/include/asm-ppc/smp.h
@@ -54,12 +54,21 @@
 	return hweight32(cpu_online_map);
 }
 
-extern inline int any_online_cpu(unsigned int mask)
+typedef unsigned long cpu_mask_t;
+#define CPU_MASK_ALL (~0UL)
+#define CPU_MASK_NONE (0UL)
+
+static inline void cpu_online_mask(cpu_mask_t *res, cpu_mask_t mask)
+{
+	*res = (mask & cpu_online_map);
+}
+
+static inline unsigned int any_online_cpu(cpu_mask_t mask)
 {
 	if (mask & cpu_online_map)
 		return __ffs(mask & cpu_online_map);
 
-	return -1;
+	return NR_CPUS;
 }
 
 extern int smp_hw_index[];

kernel/sched.c +23 ~~-21~~

133 lines not on this page · raw message

kernel/softirq.c +1 -2

diff -urN -I $.*$ --exclude TAGS -X /home/rusty/current-dontdiff --minimal linux-2.5.25/kernel/softirq.c working-2.5.25-cpumask/kernel/softirq.c
@@ -370,8 +370,7 @@
 	current->flags |= PF_IOTHREAD;
 	sigfillset(&current->blocked);
 
-	/* Migrate to the right CPU */
-	set_cpus_allowed(current, 1UL << cpu);
+	migrate_to_cpu(cpu);
 	if (smp_processor_id() != cpu)
 		BUG();

Documentation/sched-coding.txt +4 -1

diff -urN -I $.*$ --exclude TAGS -X /home/rusty/current-dontdiff --minimal linux-2.5.25/Documentation/sched-coding.txt working-2.5.25-cpumask/Documentation/sched-coding.txt
@@ -103,7 +103,10 @@
 	Sets the "nice" value of task p to the given value.
 int setscheduler(pid_t pid, int policy, struct sched_param *param)
 	Sets the scheduling policy and parameters for the given pid.
-void set_cpus_allowed(task_t *p, unsigned long new_mask)
+void migrate_to_cpu(unsigned int cpu)
+	Migrates the current task to the cpu and nails it there.  This
+	is a more convenient form of:
+void set_cpus_allowed(task_t *p, cpu_mask_t new_mask)
 	Sets a given task's CPU affinity and migrates it to a proper cpu.
 	Callers must have a valid reference to the task and assure the
 	task not exit prematurely.  No locks can be held during the call.

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