Author: jhb
Date: Fri Jun 11 15:56:18 2010
New Revision: 209050
URL: http://svn.freebsd.org/changeset/base/209050
Log:
Add helper macros to iterate over available CPUs in the system.
CPU_FOREACH(i) iterates over the CPU IDs of all available CPUs. The
CPU_FIRST() and CPU_NEXT(i) macros can also be used to iterate over
available CPU IDs. CPU_NEXT(i) wraps around to CPU_FIRST() rather than
returning some sort of terminator.
Requested by: rwatson
Reviewed by: attilio
Modified:
head/sys/sys/smp.h
Modified: head/sys/sys/smp.h
==============================================================================
--- head/sys/sys/smp.h Fri Jun 11 15:55:18 2010 (r209049)
+++ head/sys/sys/smp.h Fri Jun 11 15:56:18 2010 (r209050)
@@ -91,6 +91,44 @@ extern cpumask_t all_cpus;
*/
#define CPU_ABSENT(x_cpu) ((all_cpus & (1 << (x_cpu))) == 0)
+/*
+ * Macros to iterate over non-absent CPUs. CPU_FOREACH() takes an
+ * integer iterator and iterates over the available set of CPUs.
+ * CPU_FIRST() returns the id of the first non-absent CPU. CPU_NEXT()
+ * returns the id of the next non-absent CPU. It will wrap back to
+ * CPU_FIRST() once the end of the list is reached. The iterators are
+ * currently implemented via inline functions.
+ */
+#define CPU_FOREACH(i)
\
+ for ((i) = 0; (i) <= mp_maxid; (i)++) \
+ if (!CPU_ABSENT((i)))
+
+static __inline int
+cpu_first(void)
+{
+ int i;
+
+ for (i = 0;; i++)
+ if (!CPU_ABSENT(i))
+ return (i);
+}
+
+static __inline int
+cpu_next(int i)
+{
+
+ for (;;) {
+ i++;
+ if (i > mp_maxid)
+ i = 0;
+ if (!CPU_ABSENT(i))
+ return (i);
+ }
+}
+
+#define CPU_FIRST() cpu_first()
+#define CPU_NEXT(i) cpu_next((i))
+
#ifdef SMP
/*
* Machine dependent functions used to initialize MP support.
_______________________________________________
svn-src-head@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/svn-src-head
To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
