This patch is in regard to bugme.osdl.org bug 619, link here:
http://bugme.osdl.org/show_bug.cgi?id=619
This is the second of two patches to fix this bug. This patch fills in
include/linux/topology.h (created in the last patch) with a couple
#defines. The patch also creates a generic_hweight64() in
include/linux/bitops.h, which we've been lacking for a while. It then
uses these new macros in sched.c to ensure that if a node has no CPUs,
it is not used in scheduling decisions.
[mcd@arrakis src]$ diffstat ~/patches/node_online.patch
include/linux/bitops.h | 27 +++++++++++++++++++++++++++
include/linux/topology.h | 7 +++++++
kernel/sched.c | 2 +-
3 files changed, 35 insertions(+), 1 deletion(-)
Cheers!
-Matt
diff -Nur --exclude-from=/home/mcd/.dontdiff linux-2.5.69-add_linux_topo/include/linux/bitops.h linux-2.5.69-node_online_fix/include/linux/bitops.h
--- linux-2.5.69-add_linux_topo/include/linux/bitops.h Sun May 4 16:53:42 2003
+++ linux-2.5.69-node_online_fix/include/linux/bitops.h Mon May 5 18:00:00 2003
@@ -107,6 +107,33 @@
return (res & 0x0F) + ((res >> 4) & 0x0F);
}
+#if (BITS_PER_LONG == 64)
+
+static inline unsigned int generic_hweight64(unsigned int w)
+{
+ unsigned int res = (w & 0x5555555555555555) + ((w >> 1) & 0x5555555555555555);
+ res = (res & 0x3333333333333333) + ((res >> 2) & 0x3333333333333333);
+ res = (res & 0x0F0F0F0F0F0F0F0F) + ((res >> 4) & 0x0F0F0F0F0F0F0F0F);
+ res = (res & 0x00FF00FF00FF00FF) + ((res >> 8) & 0x00FF00FF00FF00FF);
+ res = (res & 0x0000FFFF0000FFFF) + ((res >> 16) & 0x0000FFFF0000FFFF);
+ return (res & 0x00000000FFFFFFFF) + ((res >> 32) & 0x00000000FFFFFFFF);
+}
+
+#define hweight_long(w) generic_hweight64(w)
+
+#endif /* BITS_PER_LONG == 64 */
+
+#if (BITS_PER_LONG == 32)
+
+static inline unsigned int generic_hweight64(unsigned int *w)
+{
+ return generic_hweight32(w[0]) + generic_hweight32(w[1]);
+}
+
+#define hweight_long(w) generic_hweight32(w)
+
+#endif /* BITS_PER_LONG == 32 */
+
#include <asm/bitops.h>
diff -Nur --exclude-from=/home/mcd/.dontdiff linux-2.5.69-add_linux_topo/include/linux/topology.h linux-2.5.69-node_online_fix/include/linux/topology.h
--- linux-2.5.69-add_linux_topo/include/linux/topology.h Mon May 5 17:43:35 2003
+++ linux-2.5.69-node_online_fix/include/linux/topology.h Mon May 5 18:10:29 2003
@@ -27,6 +27,13 @@
#ifndef _LINUX_TOPOLOGY_H
#define _LINUX_TOPOLOGY_H
+#include <linux/bitops.h>
#include <asm/topology.h>
+#define nr_cpus_node(node) (hweight_long(node_to_cpumask(node)))
+
+#define for_each_node_with_cpus(node) \
+ for (node = 0; node < numnodes; node++) \
+ if (nr_cpus_node(node)
+
#endif /* _LINUX_TOPOLOGY_H */
diff -Nur --exclude-from=/home/mcd/.dontdiff linux-2.5.69-add_linux_topo/kernel/sched.c linux-2.5.69-node_online_fix/kernel/sched.c
--- linux-2.5.69-add_linux_topo/kernel/sched.c Sun May 4 16:53:37 2003
+++ linux-2.5.69-node_online_fix/kernel/sched.c Mon May 5 18:10:58 2003
@@ -802,7 +802,7 @@
return best_cpu;
minload = 10000000;
- for (i = 0; i < numnodes; i++) {
+ for_each_node_with_cpus(i) {
load = atomic_read(&node_nr_running[i]);
if (load < minload) {
minload = load;
-
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This archive was generated by hypermail 2b29 : Wed May 07 2003 - 22:00:24 EST