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| author | Paul E. McKenney <paulmck@kernel.org> | 2024-02-23 15:16:20 -0800 |
|---|---|---|
| committer | Uladzislau Rezki (Sony) <urezki@gmail.com> | 2024-04-09 15:11:49 +0200 |
| commit | c342b42fa47f4257fccfeadc8e32c51b1be17a1f (patch) | |
| tree | 105317991382f0d94501cd25115be1561507970b /include/linux/rcupdate_wait.h | |
| parent | 39cd87c4eb2b893354f3b850f916353f2658ae6f (diff) | |
| download | linux-c342b42fa47f4257fccfeadc8e32c51b1be17a1f.tar.gz linux-c342b42fa47f4257fccfeadc8e32c51b1be17a1f.tar.bz2 linux-c342b42fa47f4257fccfeadc8e32c51b1be17a1f.zip | |
rcu-tasks: Make Tasks RCU wait idly for grace-period delays
Currently, all waits for grace periods sleep at TASK_UNINTERRUPTIBLE,
regardless of RCU flavor. This has worked well, but there have been
cases where a longer-than-average Tasks RCU grace period has triggered
softlockup splats, many of them, before the Tasks RCU CPU stall warning
appears. These softlockup splats unnecessarily consume console bandwidth
and complicate diagnosis of the underlying problem. Plus a long but not
pathologically long Tasks RCU grace period might trigger a few softlockup
splats before completing normally, which generates noise for no good
reason.
This commit therefore causes Tasks RCU grace periods to sleep at TASK_IDLE
priority. If there really is a persistent problem, the eventual Tasks
RCU CPU stall warning will flag it, and without the extra noise.
Reported-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Diffstat (limited to 'include/linux/rcupdate_wait.h')
| -rw-r--r-- | include/linux/rcupdate_wait.h | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/include/linux/rcupdate_wait.h b/include/linux/rcupdate_wait.h index d07f0848802e..303ab9bee155 100644 --- a/include/linux/rcupdate_wait.h +++ b/include/linux/rcupdate_wait.h @@ -19,18 +19,18 @@ struct rcu_synchronize { }; void wakeme_after_rcu(struct rcu_head *head); -void __wait_rcu_gp(bool checktiny, int n, call_rcu_func_t *crcu_array, +void __wait_rcu_gp(bool checktiny, unsigned int state, int n, call_rcu_func_t *crcu_array, struct rcu_synchronize *rs_array); -#define _wait_rcu_gp(checktiny, ...) \ -do { \ - call_rcu_func_t __crcu_array[] = { __VA_ARGS__ }; \ - struct rcu_synchronize __rs_array[ARRAY_SIZE(__crcu_array)]; \ - __wait_rcu_gp(checktiny, ARRAY_SIZE(__crcu_array), \ - __crcu_array, __rs_array); \ +#define _wait_rcu_gp(checktiny, state, ...) \ +do { \ + call_rcu_func_t __crcu_array[] = { __VA_ARGS__ }; \ + struct rcu_synchronize __rs_array[ARRAY_SIZE(__crcu_array)]; \ + __wait_rcu_gp(checktiny, state, ARRAY_SIZE(__crcu_array), __crcu_array, __rs_array); \ } while (0) -#define wait_rcu_gp(...) _wait_rcu_gp(false, __VA_ARGS__) +#define wait_rcu_gp(...) _wait_rcu_gp(false, TASK_UNINTERRUPTIBLE, __VA_ARGS__) +#define wait_rcu_gp_state(state, ...) _wait_rcu_gp(false, state, __VA_ARGS__) /** * synchronize_rcu_mult - Wait concurrently for multiple grace periods @@ -54,7 +54,7 @@ do { \ * grace period. */ #define synchronize_rcu_mult(...) \ - _wait_rcu_gp(IS_ENABLED(CONFIG_TINY_RCU), __VA_ARGS__) + _wait_rcu_gp(IS_ENABLED(CONFIG_TINY_RCU), TASK_UNINTERRUPTIBLE, __VA_ARGS__) static inline void cond_resched_rcu(void) { |