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| author | Paul E. McKenney <paul.mckenney@linaro.org> | 2013-02-11 05:48:58 +0100 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2013-03-26 16:04:44 +0100 |
| commit | dae6e64d2bcfd4b06304ab864c7e3a4f6b5fedf4 (patch) | |
| tree | 79172d32aab5e0cecf8fc7ab4cf1fabf14328d81 /kernel/rcutree.h | |
| parent | rcu: Provide compile-time control for no-CBs CPUs (diff) | |
| download | linux-dae6e64d2bcfd4b06304ab864c7e3a4f6b5fedf4.tar.xz linux-dae6e64d2bcfd4b06304ab864c7e3a4f6b5fedf4.zip | |
rcu: Introduce proper blocking to no-CBs kthreads GP waits
Currently, the no-CBs kthreads do repeated timed waits for grace periods
to elapse. This is crude and energy inefficient, so this commit allows
no-CBs kthreads to specify exactly which grace period they are waiting
for and also allows them to block for the entire duration until the
desired grace period completes.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'kernel/rcutree.h')
| -rw-r--r-- | kernel/rcutree.h | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/kernel/rcutree.h b/kernel/rcutree.h index 7af39f4aaac4..e51373c0b748 100644 --- a/kernel/rcutree.h +++ b/kernel/rcutree.h @@ -196,6 +196,12 @@ struct rcu_node { /* Refused to boost: not sure why, though. */ /* This can happen due to race conditions. */ #endif /* #ifdef CONFIG_RCU_BOOST */ +#ifdef CONFIG_RCU_NOCB_CPU + wait_queue_head_t nocb_gp_wq[2]; + /* Place for rcu_nocb_kthread() to wait GP. */ + int n_nocb_gp_requests[2]; + /* Counts of upcoming no-CB GP requests. */ +#endif /* #ifdef CONFIG_RCU_NOCB_CPU */ raw_spinlock_t fqslock ____cacheline_internodealigned_in_smp; } ____cacheline_internodealigned_in_smp; @@ -326,7 +332,6 @@ struct rcu_data { int nocb_p_count_lazy; /* (approximate). */ wait_queue_head_t nocb_wq; /* For nocb kthreads to sleep on. */ struct task_struct *nocb_kthread; - bool nocb_needs_gp; #endif /* #ifdef CONFIG_RCU_NOCB_CPU */ int cpu; @@ -524,7 +529,10 @@ static void print_cpu_stall_info(struct rcu_state *rsp, int cpu); static void print_cpu_stall_info_end(void); static void zero_cpu_stall_ticks(struct rcu_data *rdp); static void increment_cpu_stall_ticks(void); -static int rcu_nocb_needs_gp(struct rcu_data *rdp); +static int rcu_nocb_needs_gp(struct rcu_state *rsp); +static void rcu_nocb_gp_set(struct rcu_node *rnp, int nrq); +static int rcu_nocb_gp_cleanup(struct rcu_state *rsp, struct rcu_node *rnp); +static void rcu_init_one_nocb(struct rcu_node *rnp); static bool is_nocb_cpu(int cpu); static bool __call_rcu_nocb(struct rcu_data *rdp, struct rcu_head *rhp, bool lazy); |