diff options
author | David Woodhouse <David.Woodhouse@intel.com> | 2008-07-11 14:36:25 +0100 |
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committer | David Woodhouse <David.Woodhouse@intel.com> | 2008-07-11 14:36:25 +0100 |
commit | a8931ef380c92d121ae74ecfb03b2d63f72eea6f (patch) | |
tree | 980fb6b019e11e6cb1ece55b7faff184721a8053 /kernel/rcuclassic.c | |
parent | 90574d0a4d4b73308ae54a2a57a4f3f1fa98e984 (diff) | |
parent | e5a5816f7875207cb0a0a7032e39a4686c5e10a4 (diff) |
Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
Diffstat (limited to 'kernel/rcuclassic.c')
-rw-r--r-- | kernel/rcuclassic.c | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/kernel/rcuclassic.c b/kernel/rcuclassic.c index f4ffbd0f306..a38895a5b8e 100644 --- a/kernel/rcuclassic.c +++ b/kernel/rcuclassic.c @@ -89,8 +89,22 @@ static void force_quiescent_state(struct rcu_data *rdp, /* * Don't send IPI to itself. With irqs disabled, * rdp->cpu is the current cpu. + * + * cpu_online_map is updated by the _cpu_down() + * using stop_machine_run(). Since we're in irqs disabled + * section, stop_machine_run() is not exectuting, hence + * the cpu_online_map is stable. + * + * However, a cpu might have been offlined _just_ before + * we disabled irqs while entering here. + * And rcu subsystem might not yet have handled the CPU_DEAD + * notification, leading to the offlined cpu's bit + * being set in the rcp->cpumask. + * + * Hence cpumask = (rcp->cpumask & cpu_online_map) to prevent + * sending smp_reschedule() to an offlined CPU. */ - cpumask = rcp->cpumask; + cpus_and(cpumask, rcp->cpumask, cpu_online_map); cpu_clear(rdp->cpu, cpumask); for_each_cpu_mask(cpu, cpumask) smp_send_reschedule(cpu); |