[PATCH] smp_processor_id() cleanup

This patch implements a number of smp_processor_id() cleanup ideas that Arjan van de Ven and I came up with. The previous __smp_processor_id/_smp_processor_id/smp_processor_id API spaghetti was hard to follow both on the implementational and on the usage side. Some of the complexity arose from picking wrong names, some of the complexity comes from the fact that not all architectures defined __smp_processor_id. In the new code, there are two externally visible symbols: - smp_processor_id(): debug variant. - raw_smp_processor_id(): nondebug variant. Replaces all existing uses of _smp_processor_id() and __smp_processor_id(). Defined by every SMP architecture in include/asm-*/smp.h. There is one new internal symbol, dependent on DEBUG_PREEMPT: - debug_smp_processor_id(): internal debug variant, mapped to smp_processor_id(). Also, i moved debug_smp_processor_id() from lib/kernel_lock.c into a new lib/smp_processor_id.c file. All related comments got updated and/or clarified. I have build/boot tested the following 8 .config combinations on x86: {SMP,UP} x {PREEMPT,!PREEMPT} x {DEBUG_PREEMPT,!DEBUG_PREEMPT} I have also build/boot tested x64 on UP/PREEMPT/DEBUG_PREEMPT. (Other architectures are untested, but should work just fine.) Signed-off-by: Ingo Molnar <[email protected]> Signed-off-by: Arjan van de Ven <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
yshchan · Jun 22, 2005 · 39c715b · 39c715b
1 parent 8492980
commit 39c715b
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Showing 37 changed files with 119 additions and 125 deletions.
diff --git a/arch/i386/kernel/traps.c b/arch/i386/kernel/traps.c
@@ -306,7 +306,7 @@ void die(const char * str, struct pt_regs * regs, long err)
 	};
 	static int die_counter;
 
-	if (die.lock_owner != _smp_processor_id()) {
+	if (die.lock_owner != raw_smp_processor_id()) {
 		console_verbose();
 		spin_lock_irq(&die.lock);
 		die.lock_owner = smp_processor_id();

diff --git a/arch/i386/lib/delay.c b/arch/i386/lib/delay.c
@@ -34,7 +34,7 @@ inline void __const_udelay(unsigned long xloops)
 	xloops *= 4;
 	__asm__("mull %0"
 		:"=d" (xloops), "=&a" (d0)
-		:"1" (xloops),"0" (cpu_data[_smp_processor_id()].loops_per_jiffy * (HZ/4)));
+		:"1" (xloops),"0" (cpu_data[raw_smp_processor_id()].loops_per_jiffy * (HZ/4)));
         __delay(++xloops);
 }
 

diff --git a/arch/ppc/lib/locks.c b/arch/ppc/lib/locks.c
@@ -130,7 +130,7 @@ void _raw_read_lock(rwlock_t *rw)
 		while (!read_can_lock(rw)) {
 			if (--stuck == 0) {
 				printk("_read_lock(%p) CPU#%d lock %d\n",
-				       rw, _smp_processor_id(), rw->lock);
+				       rw, raw_smp_processor_id(), rw->lock);
 				stuck = INIT_STUCK;
 			}
 		}
@@ -158,7 +158,7 @@ void _raw_write_lock(rwlock_t *rw)
 		while (!write_can_lock(rw)) {
 			if (--stuck == 0) {
 				printk("write_lock(%p) CPU#%d lock %d)\n",
-				       rw, _smp_processor_id(), rw->lock);
+				       rw, raw_smp_processor_id(), rw->lock);
 				stuck = INIT_STUCK;
 			}
 		}

diff --git a/arch/ppc64/kernel/idle.c b/arch/ppc64/kernel/idle.c
@@ -292,7 +292,7 @@ static int native_idle(void)
 		if (need_resched())
 			schedule();
 
-		if (cpu_is_offline(_smp_processor_id()) &&
+		if (cpu_is_offline(raw_smp_processor_id()) &&
 		    system_state == SYSTEM_RUNNING)
 			cpu_die();
 	}

diff --git a/arch/sh/lib/delay.c b/arch/sh/lib/delay.c
@@ -24,7 +24,7 @@ inline void __const_udelay(unsigned long xloops)
 	__asm__("dmulu.l	%0, %2\n\t"
 		"sts	mach, %0"
 		: "=r" (xloops)
-		: "0" (xloops), "r" (cpu_data[_smp_processor_id()].loops_per_jiffy)
+		: "0" (xloops), "r" (cpu_data[raw_smp_processor_id()].loops_per_jiffy)
 		: "macl", "mach");
 	__delay(xloops * HZ);
 }

diff --git a/arch/sparc64/lib/delay.c b/arch/sparc64/lib/delay.c
@@ -31,7 +31,7 @@ void __const_udelay(unsigned long n)
 {
 	n *= 4;
 
-	n *= (cpu_data(_smp_processor_id()).udelay_val * (HZ/4));
+	n *= (cpu_data(raw_smp_processor_id()).udelay_val * (HZ/4));
 	n >>= 32;
 
 	__delay(n + 1);

diff --git a/arch/x86_64/lib/delay.c b/arch/x86_64/lib/delay.c
@@ -34,7 +34,7 @@ void __delay(unsigned long loops)
 
 inline void __const_udelay(unsigned long xloops)
 {
-	__delay(((xloops * cpu_data[_smp_processor_id()].loops_per_jiffy) >> 32) * HZ);
+	__delay(((xloops * cpu_data[raw_smp_processor_id()].loops_per_jiffy) >> 32) * HZ);
 }
 
 void __udelay(unsigned long usecs)

diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
@@ -171,7 +171,7 @@ static void acpi_processor_idle (void)
 	int			sleep_ticks = 0;
 	u32			t1, t2 = 0;
 
-	pr = processors[_smp_processor_id()];
+	pr = processors[raw_smp_processor_id()];
 	if (!pr)
 		return;
 

diff --git a/drivers/input/gameport/gameport.c b/drivers/input/gameport/gameport.c
@@ -134,7 +134,7 @@ static int gameport_measure_speed(struct gameport *gameport)
 	}
 
 	gameport_close(gameport);
-	return (cpu_data[_smp_processor_id()].loops_per_jiffy * (unsigned long)HZ / (1000 / 50)) / (tx < 1 ? 1 : tx);
+	return (cpu_data[raw_smp_processor_id()].loops_per_jiffy * (unsigned long)HZ / (1000 / 50)) / (tx < 1 ? 1 : tx);
 
 #else
 

diff --git a/drivers/oprofile/buffer_sync.c b/drivers/oprofile/buffer_sync.c
@@ -62,7 +62,7 @@ static int task_exit_notify(struct notifier_block * self, unsigned long val, voi
 	/* To avoid latency problems, we only process the current CPU,
 	 * hoping that most samples for the task are on this CPU
 	 */
-	sync_buffer(_smp_processor_id());
+	sync_buffer(raw_smp_processor_id());
   	return 0;
 }
 
@@ -86,7 +86,7 @@ static int munmap_notify(struct notifier_block * self, unsigned long val, void *
 		/* To avoid latency problems, we only process the current CPU,
 		 * hoping that most samples for the task are on this CPU
 		 */
-		sync_buffer(_smp_processor_id());
+		sync_buffer(raw_smp_processor_id());
 		return 0;
 	}
 

diff --git a/fs/xfs/linux-2.6/xfs_linux.h b/fs/xfs/linux-2.6/xfs_linux.h
@@ -145,10 +145,10 @@ static inline void set_buffer_unwritten_io(struct buffer_head *bh)
 #define xfs_inherit_nosymlinks	xfs_params.inherit_nosym.val
 #define xfs_rotorstep		xfs_params.rotorstep.val
 
-#ifndef __smp_processor_id
-#define __smp_processor_id()	smp_processor_id()
+#ifndef raw_smp_processor_id
+#define raw_smp_processor_id()	smp_processor_id()
 #endif
-#define current_cpu()		__smp_processor_id()
+#define current_cpu()		raw_smp_processor_id()
 #define current_pid()		(current->pid)
 #define current_fsuid(cred)	(current->fsuid)
 #define current_fsgid(cred)	(current->fsgid)

diff --git a/include/asm-alpha/smp.h b/include/asm-alpha/smp.h
@@ -43,7 +43,7 @@ extern struct cpuinfo_alpha cpu_data[NR_CPUS];
 #define PROC_CHANGE_PENALTY     20
 
 #define hard_smp_processor_id()	__hard_smp_processor_id()
-#define smp_processor_id()	(current_thread_info()->cpu)
+#define raw_smp_processor_id()	(current_thread_info()->cpu)
 
 extern cpumask_t cpu_present_mask;
 extern cpumask_t cpu_online_map;

diff --git a/include/asm-arm/smp.h b/include/asm-arm/smp.h
@@ -21,7 +21,7 @@
 # error "<asm-arm/smp.h> included in non-SMP build"
 #endif
 
-#define smp_processor_id()	(current_thread_info()->cpu)
+#define raw_smp_processor_id() (current_thread_info()->cpu)
 
 extern cpumask_t cpu_present_mask;
 #define cpu_possible_map cpu_present_mask

diff --git a/include/asm-i386/smp.h b/include/asm-i386/smp.h
@@ -51,7 +51,7 @@ extern u8 x86_cpu_to_apicid[];
  * from the initial startup. We map APIC_BASE very early in page_setup(),
  * so this is correct in the x86 case.
  */
-#define __smp_processor_id() (current_thread_info()->cpu)
+#define raw_smp_processor_id() (current_thread_info()->cpu)
 
 extern cpumask_t cpu_callout_map;
 extern cpumask_t cpu_callin_map;

diff --git a/include/asm-ia64/smp.h b/include/asm-ia64/smp.h
@@ -46,7 +46,7 @@ ia64_get_lid (void)
 #define SMP_IRQ_REDIRECTION	(1 << 0)
 #define SMP_IPI_REDIRECTION	(1 << 1)
 
-#define smp_processor_id()	(current_thread_info()->cpu)
+#define raw_smp_processor_id() (current_thread_info()->cpu)
 
 extern struct smp_boot_data {
 	int cpu_count;

diff --git a/include/asm-m32r/smp.h b/include/asm-m32r/smp.h
@@ -66,7 +66,7 @@ extern volatile int cpu_2_physid[NR_CPUS];
 #define physid_to_cpu(physid)	physid_2_cpu[physid]
 #define cpu_to_physid(cpu_id)	cpu_2_physid[cpu_id]
 
-#define smp_processor_id()	(current_thread_info()->cpu)
+#define raw_smp_processor_id()	(current_thread_info()->cpu)
 
 extern cpumask_t cpu_callout_map;
 #define cpu_possible_map cpu_callout_map

diff --git a/include/asm-mips/smp.h b/include/asm-mips/smp.h
@@ -21,7 +21,7 @@
 #include <linux/cpumask.h>
 #include <asm/atomic.h>
 
-#define smp_processor_id()	(current_thread_info()->cpu)
+#define raw_smp_processor_id() (current_thread_info()->cpu)
 
 /* Map from cpu id to sequential logical cpu number.  This will only
    not be idempotent when cpus failed to come on-line.  */

diff --git a/include/asm-parisc/smp.h b/include/asm-parisc/smp.h
@@ -51,7 +51,7 @@ extern void smp_send_reschedule(int cpu);
 
 extern unsigned long cpu_present_mask;
 
-#define smp_processor_id()	(current_thread_info()->cpu)
+#define raw_smp_processor_id()	(current_thread_info()->cpu)
 
 #endif /* CONFIG_SMP */
 

diff --git a/include/asm-ppc/smp.h b/include/asm-ppc/smp.h
@@ -44,7 +44,7 @@ extern void smp_message_recv(int, struct pt_regs *);
 #define NO_PROC_ID		0xFF            /* No processor magic marker */
 #define PROC_CHANGE_PENALTY	20
 
-#define smp_processor_id() (current_thread_info()->cpu)
+#define raw_smp_processor_id()	(current_thread_info()->cpu)
 
 extern int __cpu_up(unsigned int cpu);
 

diff --git a/include/asm-ppc64/smp.h b/include/asm-ppc64/smp.h
@@ -45,7 +45,7 @@ void generic_cpu_die(unsigned int cpu);
 void generic_mach_cpu_die(void);
 #endif
 
-#define __smp_processor_id() (get_paca()->paca_index)
+#define raw_smp_processor_id()	(get_paca()->paca_index)
 #define hard_smp_processor_id() (get_paca()->hw_cpu_id)
 
 extern cpumask_t cpu_sibling_map[NR_CPUS];

diff --git a/include/asm-s390/smp.h b/include/asm-s390/smp.h
@@ -47,7 +47,7 @@ extern int smp_call_function_on(void (*func) (void *info), void *info,
 
 #define PROC_CHANGE_PENALTY	20		/* Schedule penalty */
 
-#define smp_processor_id() (S390_lowcore.cpu_data.cpu_nr)
+#define raw_smp_processor_id()	(S390_lowcore.cpu_data.cpu_nr)
 
 extern int smp_get_cpu(cpumask_t cpu_map);
 extern void smp_put_cpu(int cpu);

diff --git a/include/asm-sh/smp.h b/include/asm-sh/smp.h
@@ -25,7 +25,7 @@ extern cpumask_t cpu_possible_map;
 
 #define cpu_online(cpu)		cpu_isset(cpu, cpu_online_map)
 
-#define smp_processor_id()	(current_thread_info()->cpu)
+#define raw_smp_processor_id()	(current_thread_info()->cpu)
 
 /* I've no idea what the real meaning of this is */
 #define PROC_CHANGE_PENALTY	20

diff --git a/include/asm-sparc/smp.h b/include/asm-sparc/smp.h
@@ -148,7 +148,7 @@ extern __inline__ int hard_smp_processor_id(void)
 }
 #endif
 
-#define smp_processor_id()	(current_thread_info()->cpu)
+#define raw_smp_processor_id()		(current_thread_info()->cpu)
 
 #define prof_multiplier(__cpu)		cpu_data(__cpu).multiplier
 #define prof_counter(__cpu)		cpu_data(__cpu).counter

diff --git a/include/asm-sparc64/smp.h b/include/asm-sparc64/smp.h
@@ -64,7 +64,7 @@ static __inline__ int hard_smp_processor_id(void)
 	}
 }
 
-#define smp_processor_id() (current_thread_info()->cpu)
+#define raw_smp_processor_id() (current_thread_info()->cpu)
 
 #endif /* !(__ASSEMBLY__) */
 

diff --git a/include/asm-um/smp.h b/include/asm-um/smp.h
@@ -8,7 +8,8 @@
 #include "asm/current.h"
 #include "linux/cpumask.h"
 
-#define smp_processor_id() (current_thread->cpu)
+#define raw_smp_processor_id() (current_thread->cpu)
+
 #define cpu_logical_map(n) (n)
 #define cpu_number_map(n) (n)
 #define PROC_CHANGE_PENALTY	15 /* Pick a number, any number */

diff --git a/include/asm-x86_64/smp.h b/include/asm-x86_64/smp.h
@@ -68,7 +68,7 @@ static inline int num_booting_cpus(void)
 	return cpus_weight(cpu_callout_map);
 }
 
-#define __smp_processor_id() read_pda(cpunumber)
+#define raw_smp_processor_id() read_pda(cpunumber)
 
 extern __inline int hard_smp_processor_id(void)
 {

diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
@@ -381,7 +381,7 @@ int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *, int, struct file *,
 
 #include <linux/topology.h>
 /* Returns the number of the current Node. */
-#define numa_node_id()		(cpu_to_node(_smp_processor_id()))
+#define numa_node_id()		(cpu_to_node(raw_smp_processor_id()))
 
 #ifndef CONFIG_DISCONTIGMEM
 

diff --git a/include/linux/smp.h b/include/linux/smp.h
@@ -92,10 +92,7 @@ void smp_prepare_boot_cpu(void);
 /*
  *	These macros fold the SMP functionality into a single CPU system
  */
-
-#if !defined(__smp_processor_id) || !defined(CONFIG_PREEMPT)
-# define smp_processor_id()			0
-#endif
+#define raw_smp_processor_id()			0
 #define hard_smp_processor_id()			0
 #define smp_call_function(func,info,retry,wait)	({ 0; })
 #define on_each_cpu(func,info,retry,wait)	({ func(info); 0; })
@@ -106,30 +103,25 @@ static inline void smp_send_reschedule(int cpu) { }
 #endif /* !SMP */
 
 /*
- * DEBUG_PREEMPT support: check whether smp_processor_id() is being
- * used in a preemption-safe way.
+ * smp_processor_id(): get the current CPU ID.
  *
- * An architecture has to enable this debugging code explicitly.
- * It can do so by renaming the smp_processor_id() macro to
- * __smp_processor_id().  This should only be done after some minimal
- * testing, because usually there are a number of false positives
- * that an architecture will trigger.
+ * if DEBUG_PREEMPT is enabled the we check whether it is
+ * used in a preemption-safe way. (smp_processor_id() is safe
+ * if it's used in a preemption-off critical section, or in
+ * a thread that is bound to the current CPU.)
  *
- * To fix a false positive (i.e. smp_processor_id() use that the
- * debugging code reports but which use for some reason is legal),
- * change the smp_processor_id() reference to _smp_processor_id(),
- * which is the nondebug variant.  NOTE: don't use this to hack around
- * real bugs.
+ * NOTE: raw_smp_processor_id() is for internal use only
+ * (smp_processor_id() is the preferred variant), but in rare
+ * instances it might also be used to turn off false positives
+ * (i.e. smp_processor_id() use that the debugging code reports but
+ * which use for some reason is legal). Don't use this to hack around
+ * the warning message, as your code might not work under PREEMPT.
  */
-#ifdef __smp_processor_id
-# if defined(CONFIG_PREEMPT) && defined(CONFIG_DEBUG_PREEMPT)
-   extern unsigned int smp_processor_id(void);
-# else
-#  define smp_processor_id() __smp_processor_id()
-# endif
-# define _smp_processor_id() __smp_processor_id()
+#ifdef CONFIG_DEBUG_PREEMPT
+  extern unsigned int debug_smp_processor_id(void);
+# define smp_processor_id() debug_smp_processor_id()
 #else
-# define _smp_processor_id() smp_processor_id()
+# define smp_processor_id() raw_smp_processor_id()
 #endif
 
 #define get_cpu()		({ preempt_disable(); smp_processor_id(); })

diff --git a/include/net/route.h b/include/net/route.h
@@ -107,7 +107,7 @@ struct rt_cache_stat
 
 extern struct rt_cache_stat *rt_cache_stat;
 #define RT_CACHE_STAT_INC(field)					  \
-		(per_cpu_ptr(rt_cache_stat, _smp_processor_id())->field++)
+		(per_cpu_ptr(rt_cache_stat, raw_smp_processor_id())->field++)
 
 extern struct ip_rt_acct *ip_rt_acct;
 

diff --git a/include/net/snmp.h b/include/net/snmp.h
@@ -128,18 +128,18 @@ struct linux_mib {
 #define SNMP_STAT_USRPTR(name)	(name[1])
 
 #define SNMP_INC_STATS_BH(mib, field) 	\
-	(per_cpu_ptr(mib[0], _smp_processor_id())->mibs[field]++)
+	(per_cpu_ptr(mib[0], raw_smp_processor_id())->mibs[field]++)
 #define SNMP_INC_STATS_OFFSET_BH(mib, field, offset)	\
-	(per_cpu_ptr(mib[0], _smp_processor_id())->mibs[field + (offset)]++)
+	(per_cpu_ptr(mib[0], raw_smp_processor_id())->mibs[field + (offset)]++)
 #define SNMP_INC_STATS_USER(mib, field) \
-	(per_cpu_ptr(mib[1], _smp_processor_id())->mibs[field]++)
+	(per_cpu_ptr(mib[1], raw_smp_processor_id())->mibs[field]++)
 #define SNMP_INC_STATS(mib, field) 	\
-	(per_cpu_ptr(mib[!in_softirq()], _smp_processor_id())->mibs[field]++)
+	(per_cpu_ptr(mib[!in_softirq()], raw_smp_processor_id())->mibs[field]++)
 #define SNMP_DEC_STATS(mib, field) 	\
-	(per_cpu_ptr(mib[!in_softirq()], _smp_processor_id())->mibs[field]--)
+	(per_cpu_ptr(mib[!in_softirq()], raw_smp_processor_id())->mibs[field]--)
 #define SNMP_ADD_STATS_BH(mib, field, addend) 	\
-	(per_cpu_ptr(mib[0], _smp_processor_id())->mibs[field] += addend)
+	(per_cpu_ptr(mib[0], raw_smp_processor_id())->mibs[field] += addend)
 #define SNMP_ADD_STATS_USER(mib, field, addend) 	\
-	(per_cpu_ptr(mib[1], _smp_processor_id())->mibs[field] += addend)
+	(per_cpu_ptr(mib[1], raw_smp_processor_id())->mibs[field] += addend)
 
 #endif
diff --git a/kernel/module.c b/kernel/module.c
@@ -379,7 +379,7 @@ static void module_unload_init(struct module *mod)
 	for (i = 0; i < NR_CPUS; i++)
 		local_set(&mod->ref[i].count, 0);
 	/* Hold reference count during initialization. */
-	local_set(&mod->ref[_smp_processor_id()].count, 1);
+	local_set(&mod->ref[raw_smp_processor_id()].count, 1);
 	/* Backwards compatibility macros put refcount during init. */
 	mod->waiter = current;
 }

diff --git a/kernel/power/smp.c b/kernel/power/smp.c
@@ -48,11 +48,11 @@ void disable_nonboot_cpus(void)
 {
 	oldmask = current->cpus_allowed;
 	set_cpus_allowed(current, cpumask_of_cpu(0));
-	printk("Freezing CPUs (at %d)", _smp_processor_id());
+	printk("Freezing CPUs (at %d)", raw_smp_processor_id());
 	current->state = TASK_INTERRUPTIBLE;
 	schedule_timeout(HZ);
 	printk("...");
-	BUG_ON(_smp_processor_id() != 0);
+	BUG_ON(raw_smp_processor_id() != 0);
 
 	/* FIXME: for this to work, all the CPUs must be running
 	 * "idle" thread (or we deadlock). Is that guaranteed? */
-Original file line number
+Diff line change
@@ Expand Up @@
     	}
     	gameport_close(gameport);
-    	return (cpu_data[_smp_processor_id()].loops_per_jiffy * (unsigned long)HZ / (1000 / 50)) / (tx < 1 ? 1 : tx);
+    	return (cpu_data[raw_smp_processor_id()].loops_per_jiffy * (unsigned long)HZ / (1000 / 50)) / (tx < 1 ? 1 : tx);
     #else
@@ Expand Down @@