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authorRusty Russell <rusty@rustcorp.com.au>2009-03-17 14:50:34 +1030
committerIngo Molnar <mingo@elte.hu>2009-03-18 09:40:35 +0100
commit30e1e6d1af2b67558bccf322af2b3e0676b209ae (patch)
treedae658631d0bb038c373cc2ba34ecf43f31ebd25 /arch/x86/kernel/process.c
parent082edb7bf443eb8eda15b482d16ad9dd8137ad24 (diff)
downloadblackbird-op-linux-30e1e6d1af2b67558bccf322af2b3e0676b209ae.tar.gz
blackbird-op-linux-30e1e6d1af2b67558bccf322af2b3e0676b209ae.zip
cpumask: fix CONFIG_CPUMASK_OFFSTACK=y cpu hotunplug crash
Impact: Fix cpu offline when CONFIG_MAXSMP=y Changeset bc9b83dd1f66402b870301c3c7117b9c1484abb4 "cpumask: convert c1e_mask in arch/x86/kernel/process.c to cpumask_var_t" contained a bug: c1e_mask is manipulated even if C1E isn't detected (and hence not allocated). This is simply fixed by checking for NULL (which gcc optimizes out anyway of CONFIG_CPUMASK_OFFSTACK=n, since it knows ce1_mask can never be NULL). In addition, fix a leak where select_idle_routine re-allocates (and re-clears) c1e_mask on every cpu init. Reported-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Mike Travis <travis@sgi.com> LKML-Reference: <200903171450.34549.rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel/process.c')
-rw-r--r--arch/x86/kernel/process.c14
1 files changed, 11 insertions, 3 deletions
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 6638294cec8d..78533a519d8f 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -479,7 +479,8 @@ static int c1e_detected;
void c1e_remove_cpu(int cpu)
{
- cpumask_clear_cpu(cpu, c1e_mask);
+ if (c1e_mask != NULL)
+ cpumask_clear_cpu(cpu, c1e_mask);
}
/*
@@ -556,13 +557,20 @@ void __cpuinit select_idle_routine(const struct cpuinfo_x86 *c)
pm_idle = mwait_idle;
} else if (check_c1e_idle(c)) {
printk(KERN_INFO "using C1E aware idle routine\n");
- alloc_cpumask_var(&c1e_mask, GFP_KERNEL);
- cpumask_clear(c1e_mask);
pm_idle = c1e_idle;
} else
pm_idle = default_idle;
}
+void __init init_c1e_mask(void)
+{
+ /* If we're using c1e_idle, we need to allocate c1e_mask. */
+ if (pm_idle == c1e_idle) {
+ alloc_cpumask_var(&c1e_mask, GFP_KERNEL);
+ cpumask_clear(c1e_mask);
+ }
+}
+
static int __init idle_setup(char *str)
{
if (!str)
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