2002-08-17 13:08:02

by Luca Barbieri

[permalink] [raw]
Subject: [PATCH] [2.5] is_smp() and can_be_smp()

Will be used by another patch that I'll post in the near future.
For i386 cpucount is used rather than computing the hweight of
cpu_online_map since it's faster and already there.
Ideally the same should be done for all architectures in both these
macros and num_online_cpus and num_possible_cpus.


diff --exclude-from=/home/ldb/src/linux-exclude -urNdp a/include/asm-i386/smp.h b/include/asm-i386/smp.h
--- a/include/asm-i386/smp.h 2002-08-13 19:36:13.000000000 +0200
+++ b/include/asm-i386/smp.h 2002-08-17 14:45:50.000000000 +0200
@@ -95,6 +95,10 @@ extern inline unsigned int num_online_cp
return hweight32(cpu_online_map);
}

+extern int cpucount;
+#define is_smp() (cpucount)
+#define can_be_smp() (cpucount)
+
extern inline int any_online_cpu(unsigned int mask)
{
if (mask & cpu_online_map)
diff --exclude-from=/home/ldb/src/linux-exclude -urNdp a/include/linux/smp.h b/include/linux/smp.h
--- a/include/linux/smp.h 2002-08-13 19:58:12.000000000 +0200
+++ b/include/linux/smp.h 2002-08-16 04:57:31.000000000 +0200
@@ -78,6 +78,19 @@ extern int register_cpu_notifier(struct
extern void unregister_cpu_notifier(struct notifier_block *nb);

int cpu_up(unsigned int cpu);
+
+#ifndef is_smp
+#define is_smp() (num_online_cpus() > 1)
+#endif
+
+#ifndef can_be_smp
+#ifdef num_possible_cpus
+#define can_be_smp() (num_possible_cpus() > 1)
+#else
+#define can_be_smp() is_smp()
+#endif
+#endif
+
#else /* !SMP */

/*
@@ -96,6 +109,8 @@ static inline void smp_send_reschedule_a
#define cpu_online_map 1
#define cpu_online(cpu) ({ cpu; 1; })
#define num_online_cpus() 1
+#define is_smp() 0
+#define can_be_smp() 0
#define __per_cpu_data
#define per_cpu(var, cpu) var
#define this_cpu(var) var


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