One liner to fix num_cpus == 0 on SMP kernel w/ UP box
Index: linux-2.5.60/arch/s390x/kernel/smp.c
===================================================================
RCS file: /build/cvsroot/linux-2.5.60/arch/s390x/kernel/smp.c,v
retrieving revision 1.1.1.1
diff -u -r1.1.1.1 smp.c
--- linux-2.5.60/arch/s390x/kernel/smp.c 10 Feb 2003 22:15:48 -0000 1.1.1.1
+++ linux-2.5.60/arch/s390x/kernel/smp.c 14 Feb 2003 12:23:34 -0000
@@ -101,28 +101,34 @@
* in the system.
*/
-int smp_call_function (void (*func) (void *info), void *info, int nonatomic,
- int wait)
/*
- * [SUMMARY] Run a function on all other CPUs.
- * <func> The function to run. This must be fast and non-blocking.
- * <info> An arbitrary pointer to pass to the function.
- * <nonatomic> currently unused.
- * <wait> If true, wait (atomically) until function has completed on other CPUs.
- * [RETURNS] 0 on success, else a negative status code. Does not return until
- * remote CPUs are nearly ready to execute <<func>> or are or have executed.
+ * smp_call_function_on_cpu - Runs func on all processors in the mask
+ *
+ * @func: The function to run. This must be fast and non-blocking.
+ * @info: An arbitrary pointer to pass to the function.
+ * @wait: If true, wait (atomically) until function has completed on other CPUs.
+ * @mask: The bitmask of CPUs to call the function
+ *
+ * Returns 0 on success, else a negative status code. Does not return until
+ * remote CPUs are nearly ready to execute func or have executed it.
*
* You must not call this function with disabled interrupts or from a
* hardware interrupt handler or from a bottom half handler.
*/
+
+int smp_call_function_on_cpu (void (*func) (void *info), void *info, int wait,
+ unsigned long mask)
{
struct call_data_struct data;
- int cpus = num_online_cpus()-1;
+ int cpu, i, num_cpus;
- /* FIXME: get cpu lock -hc */
- if (cpus <= 0)
+ cpu = get_cpu();
+ mask &= ~(1UL << cpu);
+ num_cpus = hweight64(mask);
+ if (num_cpus == 0) {
+ put_cpu_no_resched();
return 0;
-
+ }
data.func = func;
data.info = info;
atomic_set(&data.started, 0);
@@ -133,18 +139,28 @@
spin_lock(&call_lock);
call_data = &data;
/* Send a message to all other CPUs and wait for them to respond */
- smp_ext_bitcall_others(ec_call_function);
+ for (i = 0; i < NR_CPUS; i++) {
+ if (cpu_online(i) && ((1UL << i) & mask))
+ smp_ext_bitcall(i, ec_call_function);
+ }
/* Wait for response */
- while (atomic_read(&data.started) != cpus)
+ while (atomic_read(&data.started) != num_cpus)
barrier();
if (wait)
- while (atomic_read(&data.finished) != cpus)
+ while (atomic_read(&data.finished) != num_cpus)
barrier();
- spin_unlock(&call_lock);
+ spin_unlock(&call_lock);
+ put_cpu_no_resched();
return 0;
+}
+
+int smp_call_function (void (*func) (void *info), void *info, int nonatomic,
+ int wait)
+{
+ return smp_call_function_on_cpu(func, info, wait, cpu_online_map);
}
static inline void do_send_stop(void)
-
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This archive was generated by hypermail 2b29 : Sat Feb 15 2003 - 22:00:53 EST