Messages in this thread Patch in this message | | | From | John Kacur <> | Subject | [PATCH RT] rcu: Fix build break | Date | Fri, 13 Apr 2012 12:54:21 +0200 |
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A build break can occur with the following config options enabled
CONFIG_PREEMPT_RT_FULL CONFIG_RCU_FAST_NO_HZ CONFIG_RCU_CPU_STALL_INFO
This occurs because symbols in print_cpu_stall_fast_no_hz() such as rcu_idle_gp_timer are not accessible with CONFIG_PREEMPT_RT_FULL and results in the following type of build errors:
kernel/rcutree_plugin.h: In function ‘print_cpu_stall_fast_no_hz’: kernel/rcutree_plugin.h:2195: error: ‘rcu_idle_gp_timer’ undeclared (first use in this function)
This patch fixes the build break by limiting the to the function rcu_needs_cpu() instead of to the entire !defined(CONFIG_RCU_FAST_NO_NZ) section
as was intended in the original rcu: Make ksoftirqd do RCU quiescent states patch.
Signed-off-by: John Kacur <jkacur@redhat.com> --- kernel/rcutree_plugin.h | 5 +++++ 1 files changed, 5 insertions(+), 0 deletions(-)
diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h index 14acafc..2844d7d 100644 --- a/kernel/rcutree_plugin.h +++ b/kernel/rcutree_plugin.h @@ -1914,6 +1914,9 @@ int rcu_needs_cpu(int cpu) { return rcu_cpu_has_callbacks(cpu); } +#endif /* !defined(CONFIG_RCU_FAST_NO_HZ) || defined(CONFIG_PREEMPT_RT_FULL) */ + +#if !defined(CONFIG_RCU_FAST_NO_HZ) /* * Because we do not have RCU_FAST_NO_HZ, don't bother initializing for it. @@ -1984,6 +1987,7 @@ static DEFINE_PER_CPU(struct hrtimer, rcu_idle_gp_timer); static ktime_t rcu_idle_gp_wait; /* If some non-lazy callbacks. */ static ktime_t rcu_idle_lazy_gp_wait; /* If only lazy callbacks. */ +#ifndef CONFIG_PREEMPT_RT_FULL /* * Allow the CPU to enter dyntick-idle mode if either: (1) There are no * callbacks on this CPU, (2) this CPU has not yet attempted to enter @@ -2001,6 +2005,7 @@ int rcu_needs_cpu(int cpu) /* Otherwise, RCU needs the CPU only if it recently tried and failed. */ return per_cpu(rcu_dyntick_holdoff, cpu) == jiffies; } +#endif /* #ifndef CONFIG_PREEMPT_RT_FULL */ /* * Does the specified flavor of RCU have non-lazy callbacks pending on -- 1.7.2.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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