diff options
| author | Paul E. McKenney <paulmck@kernel.org> | 2020-08-08 07:56:31 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2020-08-24 18:40:27 -0700 |
| commit | a657f2617010ae237db5693f875968c28e8f732f (patch) | |
| tree | a4cf1d4ed7377d6829cfc0c1a968ce9b093d5607 /kernel/rcu/tree.h | |
| parent | 3d29aaf1ef992b5b4612fe32b9e6f517f7bba904 (diff) | |
rcu: Execute RCU reader shortly after rcu_core for strict GPs
A kernel built with CONFIG_RCU_STRICT_GRACE_PERIOD=y needs a quiescent
state to appear very shortly after a CPU has noticed a new grace period.
Placing an RCU reader immediately after this point is ineffective because
this normally happens in softirq context, which acts as a big RCU reader.
This commit therefore introduces a new per-CPU work_struct, which is
used at the end of rcu_core() processing to schedule an RCU read-side
critical section from within a clean environment.
Reported-by Jann Horn <jannh@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'kernel/rcu/tree.h')
| -rw-r--r-- | kernel/rcu/tree.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h index c96ae351688b..5831ac0b254f 100644 --- a/kernel/rcu/tree.h +++ b/kernel/rcu/tree.h @@ -164,6 +164,7 @@ struct rcu_data { /* period it is aware of. */ struct irq_work defer_qs_iw; /* Obtain later scheduler attention. */ bool defer_qs_iw_pending; /* Scheduler attention pending? */ + struct work_struct strict_work; /* Schedule readers for strict GPs. */ /* 2) batch handling */ struct rcu_segcblist cblist; /* Segmented callback list, with */ |