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| author | Uladzislau Rezki <uladzislau.rezki@sony.com> | 2022-02-16 14:52:09 +0100 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2022-05-11 20:38:50 +0200 |
| commit | 28b3ae426598e722cf5d5ab9cc7038791b955a56 (patch) | |
| tree | 3fddab261f875fe8e828bbb42d5a190df6ad8144 /kernel/rcu/tree_exp.h | |
| parent | Linux 5.18-rc1 (diff) | |
| download | linux-28b3ae426598e722cf5d5ab9cc7038791b955a56.tar.xz linux-28b3ae426598e722cf5d5ab9cc7038791b955a56.zip | |
rcu: Introduce CONFIG_RCU_EXP_CPU_STALL_TIMEOUT
Currently both expedited and regular grace period stall warnings use
a single timeout value that with units of seconds. However, recent
Android use cases problem require a sub-100-millisecond expedited RCU CPU
stall warning. Given that expedited RCU grace periods normally complete
in far less than a single millisecond, especially for small systems,
this is not unreasonable.
Therefore introduce the CONFIG_RCU_EXP_CPU_STALL_TIMEOUT kernel
configuration that defaults to 20 msec on Android and remains the same
as that of the non-expedited stall warnings otherwise. It also can be
changed in run-time via: /sys/.../parameters/rcu_exp_cpu_stall_timeout.
[ paulmck: Default of zero to use CONFIG_RCU_STALL_TIMEOUT. ]
Signed-off-by: Uladzislau Rezki <uladzislau.rezki@sony.com>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'kernel/rcu/tree_exp.h')
| -rw-r--r-- | kernel/rcu/tree_exp.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h index 60197ea24ceb..b1f52b59fa4b 100644 --- a/kernel/rcu/tree_exp.h +++ b/kernel/rcu/tree_exp.h @@ -496,7 +496,7 @@ static void synchronize_rcu_expedited_wait(void) struct rcu_node *rnp_root = rcu_get_root(); trace_rcu_exp_grace_period(rcu_state.name, rcu_exp_gp_seq_endval(), TPS("startwait")); - jiffies_stall = rcu_jiffies_till_stall_check(); + jiffies_stall = rcu_exp_jiffies_till_stall_check(); jiffies_start = jiffies; if (tick_nohz_full_enabled() && rcu_inkernel_boot_has_ended()) { if (synchronize_rcu_expedited_wait_once(1)) @@ -571,7 +571,7 @@ static void synchronize_rcu_expedited_wait(void) dump_cpu_task(cpu); } } - jiffies_stall = 3 * rcu_jiffies_till_stall_check() + 3; + jiffies_stall = 3 * rcu_exp_jiffies_till_stall_check() + 3; } } |