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| author | Paul E. McKenney <paulmck@linux.ibm.com> | 2018-09-21 18:08:09 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.ibm.com> | 2018-12-01 12:45:34 -0800 |
| commit | 5ab7ab8362fa8a4f7995d65ea05edf71530e8004 (patch) | |
| tree | 4190fcc5cbb3e11acfb85f70efeae31193b16c26 /kernel | |
| parent | 6b3de7a172bc59010a9d8e425877d98c1f24555e (diff) | |
| download | linux-5ab7ab8362fa8a4f7995d65ea05edf71530e8004.tar.bz2 | |
rcutorture: Affinity forward-progress test to avoid housekeeping CPUs
This commit affinities the forward-progress tests to avoid hogging a
housekeeping CPU on the theory that the offloaded callbacks will be
running on those housekeeping CPUs.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
[ paulmck: Fix NULL-pointer issue located by kbuild test robot. ]
Tested-by: Rong Chen <rong.a.chen@intel.com>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/rcu/rcu.h | 2 | ||||
| -rw-r--r-- | kernel/rcu/rcutorture.c | 1 | ||||
| -rw-r--r-- | kernel/rcu/tree_plugin.h | 11 |
3 files changed, 14 insertions, 0 deletions
diff --git a/kernel/rcu/rcu.h b/kernel/rcu/rcu.h index 2866166863f0..0f0f5ae8c3d4 100644 --- a/kernel/rcu/rcu.h +++ b/kernel/rcu/rcu.h @@ -539,8 +539,10 @@ extern struct workqueue_struct *rcu_par_gp_wq; #ifdef CONFIG_RCU_NOCB_CPU bool rcu_is_nocb_cpu(int cpu); +void rcu_bind_current_to_nocb(void); #else static inline bool rcu_is_nocb_cpu(int cpu) { return false; } +static inline void rcu_bind_current_to_nocb(void) { } #endif #endif /* __LINUX_RCU_H */ diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index bcc33bb8d9a6..36a3bc42782d 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -1803,6 +1803,7 @@ static int rcu_torture_fwd_prog(void *args) int tested_tries = 0; VERBOSE_TOROUT_STRING("rcu_torture_fwd_progress task started"); + rcu_bind_current_to_nocb(); if (!IS_ENABLED(CONFIG_SMP) || !IS_ENABLED(CONFIG_RCU_BOOST)) set_user_nice(current, MAX_NICE); do { diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index 605ff3b06098..25fe26c4e9c1 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -2603,6 +2603,17 @@ static bool init_nocb_callback_list(struct rcu_data *rdp) return true; } +/* + * Bind the current task to the offloaded CPUs. If there are no offloaded + * CPUs, leave the task unbound. Splat if the bind attempt fails. + */ +void rcu_bind_current_to_nocb(void) +{ + if (cpumask_available(rcu_nocb_mask) && cpumask_weight(rcu_nocb_mask)) + WARN_ON(sched_setaffinity(current->pid, rcu_nocb_mask)); +} +EXPORT_SYMBOL_GPL(rcu_bind_current_to_nocb); + #else /* #ifdef CONFIG_RCU_NOCB_CPU */ static bool rcu_nocb_cpu_needs_barrier(int cpu) |