2005-11-18 19:30:43

by John Hawkes

[permalink] [raw]
Subject: [PATCH] fix bug in sn/ia64 for sparse CPU numbering

The kernel's use of the for_each_*cpu(i) macros has allowed for sparse CPU
numbering. When I hacked the kernel to test sparse cpu_present_map[] and
cpu_possible_map[] cpumasks, I discovered one remaining spot, in
sn_hwperf_ioctl() during sn initialization, that needs to be fixed.

This is a patch against 2.6.14.

Signed-off-by: John Hawkes <[email protected]>
Signed-off-by: Dean Roe <[email protected]>

Index: linux/arch/ia64/sn/kernel/sn2/sn_hwperf.c
===================================================================
--- linux.orig/arch/ia64/sn/kernel/sn2/sn_hwperf.c 2005-11-09 16:51:25.000000000 -0800
+++ linux/arch/ia64/sn/kernel/sn2/sn_hwperf.c 2005-11-10 09:45:30.000000000 -0800
@@ -743,13 +743,14 @@
if ((r = sn_hwperf_enum_objects(&nobj, &objs)) == 0) {
memset(p, 0, a.sz);
for (i = 0; i < nobj; i++) {
+ int cpuobj_index = 0;
if (!SN_HWPERF_IS_NODE(objs + i))
continue;
node = sn_hwperf_obj_to_cnode(objs + i);
for_each_online_cpu(j) {
if (node != cpu_to_node(j))
continue;
- cpuobj = (struct sn_hwperf_object_info *) p + j;
+ cpuobj = (struct sn_hwperf_object_info *) p + cpuobj_index++;
slice = 'a' + cpuid_to_slice(j);
cdata = cpu_data(j);
cpuobj->id = j;