[PATCH 1/2] Make for_each_cpu() Iterator More Friendly

From: Rusty Russell
Date: Tue Dec 30 2003 - 20:33:35 EST

Please apply. Applies against 2.6.0-mm2 and 2.6.0-bk3. Yay!

Anton: breaks PPC64, as it needs cpu_possible_mask, but fix is already
in Ameslab tree.

Name: Make for_each_cpu() more friendly.
Author: Rusty Russell
Status: Booted on 2.6.0

D: The for_each_cpu() and for_each_online_cpu() iterators take a mask,
D: and noone uses them that way (except for arch/i386/mach-voyager, which
D: uses for_each_cpu(cpu_online_mask). Make them more usable iterators,
D: by dropping the "mask" arg.
D:
D: This requires that archs provide a cpu_possible_mask: most do,
D: but PPC64 doesn't, so it is broken by this patch. The other archs
D: use a #define to define it in asm/smp.h.
D:
D: Most places doing loops over cpus testing for cpu_online() should use
D: for_each_cpu: it is synonymous at the moment, but with the CPU hotplug patch
D: the difference becomes important.
D:
D: Followup patches will convert users.
D:
D: Thanks!
D: Rusty.

diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .18232-linux-2.6.0-bk3/arch/i386/mach-voyager/voyager_smp.c .18232-linux-2.6.0-bk3.updated/arch/i386/mach-voyager/voyager_smp.c
--- .18232-linux-2.6.0-bk3/arch/i386/mach-voyager/voyager_smp.c 2003-11-24 15:42:27.000000000 +1100
+++ .18232-linux-2.6.0-bk3.updated/arch/i386/mach-voyager/voyager_smp.c 2003-12-31 11:39:42.000000000 +1100
@@ -130,7 +130,7 @@ send_QIC_CPI(__u32 cpuset, __u8 cpi)
{
int cpu;

- for_each_cpu(cpu, cpu_online_map) {
+ for_each_online_cpu(cpu) {
if(cpuset & (1<<cpu)) {
#ifdef VOYAGER_DEBUG
if(!cpu_isset(cpu, cpu_online_map))
@@ -1465,7 +1465,7 @@ send_CPI(__u32 cpuset, __u8 cpi)
cpuset &= 0xff; /* only first 8 CPUs vaild for VIC CPI */
if(cpuset == 0)
return;
- for_each_cpu(cpu, cpu_online_map) {
+ for_each_online_cpu(cpu) {
if(cpuset & (1<<cpu))
set_bit(cpi, &vic_cpi_mailbox[cpu]);
}
@@ -1579,7 +1579,7 @@ enable_vic_irq(unsigned int irq)
VDEBUG(("VOYAGER: enable_vic_irq(%d) CPU%d affinity 0x%lx\n",
irq, cpu, cpu_irq_affinity[cpu]));
spin_lock_irqsave(&vic_irq_lock, flags);
- for_each_cpu(real_cpu, cpu_online_map) {
+ for_each_online_cpu(real_cpu) {
if(!(voyager_extended_vic_processors & (1<<real_cpu)))
continue;
if(!(cpu_irq_affinity[real_cpu] & mask)) {
@@ -1720,7 +1720,7 @@ after_handle_vic_irq(unsigned int irq)
int i;
__u8 cpu = smp_processor_id();
__u8 real_cpu;
- int mask;
+ int mask; /* Um... initialize me??? --RR */

printk("VOYAGER SMP: CPU%d lost interrupt %d\n",
cpu, irq);
@@ -1809,7 +1809,7 @@ set_vic_irq_affinity(unsigned int irq, c
* bus) */
return;

- for_each_cpu(cpu, cpu_online_map) {
+ for_each_online_cpu(cpu) {
unsigned long cpu_mask = 1 << cpu;

if(cpu_mask & real_mask) {
@@ -1875,7 +1875,7 @@ voyager_smp_dump()
int old_cpu = smp_processor_id(), cpu;

/* dump the interrupt masks of each processor */
- for_each_cpu(cpu, cpu_online_map) {
+ for_each_online_cpu(cpu) {
__u16 imr, isr, irr;
unsigned long flags;

diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .18232-linux-2.6.0-bk3/include/asm-alpha/smp.h .18232-linux-2.6.0-bk3.updated/include/asm-alpha/smp.h
--- .18232-linux-2.6.0-bk3/include/asm-alpha/smp.h 2003-09-29 10:25:56.000000000 +1000
+++ .18232-linux-2.6.0-bk3.updated/include/asm-alpha/smp.h 2003-12-31 11:39:43.000000000 +1100
@@ -48,8 +48,8 @@ extern struct cpuinfo_alpha cpu_data[NR_
extern cpumask_t cpu_present_mask;
extern cpumask_t cpu_online_map;
extern int smp_num_cpus;
+#define cpu_possible_map cpu_present_map

-#define cpu_possible(cpu) cpu_isset(cpu, cpu_present_mask)
#define cpu_online(cpu) cpu_isset(cpu, cpu_online_map)

extern int smp_call_function_on_cpu(void (*func) (void *info), void *info,int retry, int wait, unsigned long cpu);
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .18232-linux-2.6.0-bk3/include/asm-i386/smp.h .18232-linux-2.6.0-bk3.updated/include/asm-i386/smp.h
--- .18232-linux-2.6.0-bk3/include/asm-i386/smp.h 2003-09-22 10:28:12.000000000 +1000
+++ .18232-linux-2.6.0-bk3.updated/include/asm-i386/smp.h 2003-12-31 11:39:43.000000000 +1100
@@ -53,8 +53,7 @@ extern void zap_low_mappings (void);
#define smp_processor_id() (current_thread_info()->cpu)

extern cpumask_t cpu_callout_map;
-
-#define cpu_possible(cpu) cpu_isset(cpu, cpu_callout_map)
+#define cpu_possible_map cpu_callout_map

/* We don't mark CPUs online until __cpu_up(), so we need another measure */
static inline int num_booting_cpus(void)
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .18232-linux-2.6.0-bk3/include/asm-ia64/smp.h .18232-linux-2.6.0-bk3.updated/include/asm-ia64/smp.h
--- .18232-linux-2.6.0-bk3/include/asm-ia64/smp.h 2003-09-22 10:27:36.000000000 +1000
+++ .18232-linux-2.6.0-bk3.updated/include/asm-ia64/smp.h 2003-12-31 11:39:43.000000000 +1100
@@ -48,7 +48,7 @@ extern volatile int ia64_cpu_to_sapicid[

extern unsigned long ap_wakeup_vector;

-#define cpu_possible(cpu) cpu_isset(cpu, phys_cpu_present_map)
+#define cpu_possible_map phys_cpu_present_map

/*
* Function to map hard smp processor id to logical id. Slow, so don't use this in
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .18232-linux-2.6.0-bk3/include/asm-mips/smp.h .18232-linux-2.6.0-bk3.updated/include/asm-mips/smp.h
--- .18232-linux-2.6.0-bk3/include/asm-mips/smp.h 2003-09-22 10:27:36.000000000 +1000
+++ .18232-linux-2.6.0-bk3.updated/include/asm-mips/smp.h 2003-12-31 11:39:43.000000000 +1100
@@ -48,8 +48,8 @@ extern struct call_data_struct *call_dat

extern cpumask_t phys_cpu_present_map;
extern cpumask_t cpu_online_map;
+#define cpu_possible_map phys_cpu_present_map

-#define cpu_possible(cpu) cpu_isset(cpu, phys_cpu_present_map)
#define cpu_online(cpu) cpu_isset(cpu, cpu_online_map)

static inline unsigned int num_online_cpus(void)
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .18232-linux-2.6.0-bk3/include/asm-parisc/smp.h .18232-linux-2.6.0-bk3.updated/include/asm-parisc/smp.h
--- .18232-linux-2.6.0-bk3/include/asm-parisc/smp.h 2003-09-22 10:27:36.000000000 +1000
+++ .18232-linux-2.6.0-bk3.updated/include/asm-parisc/smp.h 2003-12-31 11:39:43.000000000 +1100
@@ -54,7 +54,7 @@ extern unsigned long cpu_present_mask;
#define smp_processor_id() (current_thread_info()->cpu)
#define cpu_online(cpu) cpu_isset(cpu, cpu_online_map)

-#define cpu_possible(cpu) cpu_isset(cpu, cpu_present_mask)
+#define cpu_possible_map cpu_present_map

#endif /* CONFIG_SMP */

diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .18232-linux-2.6.0-bk3/include/asm-ppc/smp.h .18232-linux-2.6.0-bk3.updated/include/asm-ppc/smp.h
--- .18232-linux-2.6.0-bk3/include/asm-ppc/smp.h 2003-09-22 10:27:36.000000000 +1000
+++ .18232-linux-2.6.0-bk3.updated/include/asm-ppc/smp.h 2003-12-31 11:39:43.000000000 +1100
@@ -48,7 +48,6 @@ extern void smp_local_timer_interrupt(st
#define smp_processor_id() (current_thread_info()->cpu)

#define cpu_online(cpu) cpu_isset(cpu, cpu_online_map)
-#define cpu_possible(cpu) cpu_isset(cpu, cpu_possible_map)

extern int __cpu_up(unsigned int cpu);

diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .18232-linux-2.6.0-bk3/include/asm-s390/smp.h .18232-linux-2.6.0-bk3.updated/include/asm-s390/smp.h
--- .18232-linux-2.6.0-bk3/include/asm-s390/smp.h 2003-09-29 10:26:01.000000000 +1000
+++ .18232-linux-2.6.0-bk3.updated/include/asm-s390/smp.h 2003-12-31 11:39:43.000000000 +1100
@@ -49,7 +49,6 @@ extern cpumask_t cpu_possible_map;
#define smp_processor_id() (S390_lowcore.cpu_data.cpu_nr)

#define cpu_online(cpu) cpu_isset(cpu, cpu_online_map)
-#define cpu_possible(cpu) cpu_isset(cpu, cpu_possible_map)

extern __inline__ __u16 hard_smp_processor_id(void)
{
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .18232-linux-2.6.0-bk3/include/asm-sh/smp.h .18232-linux-2.6.0-bk3.updated/include/asm-sh/smp.h
--- .18232-linux-2.6.0-bk3/include/asm-sh/smp.h 2003-09-22 10:23:00.000000000 +1000
+++ .18232-linux-2.6.0-bk3.updated/include/asm-sh/smp.h 2003-12-31 11:39:43.000000000 +1100
@@ -16,7 +16,6 @@
extern unsigned long cpu_online_map;

#define cpu_online(cpu) (cpu_online_map & (1 << (cpu)))
-#define cpu_possible(cpu) (cpu_online(cpu))

#define smp_processor_id() (current_thread_info()->cpu)

diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .18232-linux-2.6.0-bk3/include/asm-sparc64/smp.h .18232-linux-2.6.0-bk3.updated/include/asm-sparc64/smp.h
--- .18232-linux-2.6.0-bk3/include/asm-sparc64/smp.h 2003-09-22 10:27:37.000000000 +1000
+++ .18232-linux-2.6.0-bk3.updated/include/asm-sparc64/smp.h 2003-12-31 11:39:43.000000000 +1100
@@ -33,7 +33,7 @@
extern unsigned char boot_cpu_id;

extern cpumask_t phys_cpu_present_map;
-#define cpu_possible(cpu) cpu_isset(cpu, phys_cpu_present_map)
+#define cpu_possible_map phys_cpu_present_map

#define cpu_online(cpu) cpu_isset(cpu, cpu_online_map)

diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .18232-linux-2.6.0-bk3/include/asm-um/smp.h .18232-linux-2.6.0-bk3.updated/include/asm-um/smp.h
--- .18232-linux-2.6.0-bk3/include/asm-um/smp.h 2003-09-22 10:27:37.000000000 +1000
+++ .18232-linux-2.6.0-bk3.updated/include/asm-um/smp.h 2003-12-31 11:39:43.000000000 +1100
@@ -20,7 +20,7 @@ extern int hard_smp_processor_id(void);
#define cpu_online(cpu) cpu_isset(cpu, cpu_online_map)

extern int ncpus;
-#define cpu_possible(cpu) (cpu < ncpus)
+

extern inline void smp_cpus_done(unsigned int maxcpus)
{
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .18232-linux-2.6.0-bk3/include/asm-x86_64/smp.h .18232-linux-2.6.0-bk3.updated/include/asm-x86_64/smp.h
--- .18232-linux-2.6.0-bk3/include/asm-x86_64/smp.h 2003-11-24 15:42:33.000000000 +1100
+++ .18232-linux-2.6.0-bk3.updated/include/asm-x86_64/smp.h 2003-12-31 11:39:43.000000000 +1100
@@ -57,8 +57,7 @@ void smp_stop_cpu(void);
*/

extern cpumask_t cpu_callout_map;
-
-#define cpu_possible(cpu) cpu_isset(cpu, cpu_callout_map)
+#define cpu_possible_map cpu_callout_map
#define cpu_online(cpu) cpu_isset(cpu, cpu_online_map)

static inline int num_booting_cpus(void)
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .18232-linux-2.6.0-bk3/include/linux/cpumask.h .18232-linux-2.6.0-bk3.updated/include/linux/cpumask.h
--- .18232-linux-2.6.0-bk3/include/linux/cpumask.h 2003-12-31 10:04:40.000000000 +1100
+++ .18232-linux-2.6.0-bk3.updated/include/linux/cpumask.h 2003-12-31 11:40:59.000000000 +1100
@@ -8,32 +8,28 @@
#ifdef CONFIG_SMP

extern cpumask_t cpu_online_map;
+extern cpumask_t cpu_possible_map;

#define num_online_cpus() cpus_weight(cpu_online_map)
#define cpu_online(cpu) cpu_isset(cpu, cpu_online_map)
+#define cpu_possible(cpu) cpu_isset(cpu, cpu_possible_map)
+
+#define for_each_cpu_mask(cpu, mask) \
+ for (cpu = first_cpu_const(mask); \
+ cpu < NR_CPUS; \
+ cpu = next_cpu_const(cpu, mask))
+
+#define for_each_cpu(cpu) for_each_cpu_mask(cpu, cpu_possible_map)
+#define for_each_online_cpu(cpu) for_each_cpu_mask(cpu, cpu_online_map)
#else
#define cpu_online_map cpumask_of_cpu(0)
#define num_online_cpus() 1
#define cpu_online(cpu) ({ BUG_ON((cpu) != 0); 1; })
-#endif
-
-static inline int next_online_cpu(int cpu, cpumask_t map)
-{
- do
- cpu = next_cpu_const(cpu, mk_cpumask_const(map));
- while (cpu < NR_CPUS && !cpu_online(cpu));
- return cpu;
-}
-
-#define for_each_cpu(cpu, map) \
- for (cpu = first_cpu_const(mk_cpumask_const(map)); \
- cpu < NR_CPUS; \
- cpu = next_cpu_const(cpu,mk_cpumask_const(map)))
+#define cpu_possible(cpu) ({ BUG_ON((cpu) != 0); 1; })

-#define for_each_online_cpu(cpu, map) \
- for (cpu = first_cpu_const(mk_cpumask_const(map)); \
- cpu < NR_CPUS; \
- cpu = next_online_cpu(cpu,map))
+#define for_each_cpu(cpu) for (cpu = 0; cpu < 1; cpu++)
+#define for_each_online_cpu(cpu) for (cpu = 0; cpu < 1; cpu++)
+#endif

extern int __mask_snprintf_len(char *buf, unsigned int buflen,
const unsigned long *maskp, unsigned int maskbytes);
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .18232-linux-2.6.0-bk3/include/linux/smp.h .18232-linux-2.6.0-bk3.updated/include/linux/smp.h
--- .18232-linux-2.6.0-bk3/include/linux/smp.h 2003-09-22 10:27:37.000000000 +1000
+++ .18232-linux-2.6.0-bk3.updated/include/linux/smp.h 2003-12-31 11:39:43.000000000 +1100
@@ -103,7 +103,6 @@ void smp_prepare_boot_cpu(void);
#define on_each_cpu(func,info,retry,wait) ({ func(info); 0; })
static inline void smp_send_reschedule(int cpu) { }
#define num_booting_cpus() 1
-#define cpu_possible(cpu) ({ BUG_ON((cpu) != 0); 1; })
#define smp_prepare_boot_cpu() do {} while (0)

#endif /* !SMP */

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