From d633198088bd9e358566c470ed182994403acc7a Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Tue, 10 Oct 2017 13:52:30 -0700 Subject: srcu: Prohibit call_srcu() use under raw spinlocks Invoking queue_delayed_work() while holding a raw spinlock is forbidden in -rt kernels, which is exactly what __call_srcu() does, indirectly via srcu_funnel_gp_start(). This commit therefore downgrades Tree SRCU's locking from raw to non-raw spinlocks, which works because call_srcu() is not ever called while holding a raw spinlock. Reported-by: Sebastian Andrzej Siewior Signed-off-by: Paul E. McKenney --- include/linux/srcutree.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'include/linux/srcutree.h') diff --git a/include/linux/srcutree.h b/include/linux/srcutree.h index a949f4f9e4d7..4eda108abee0 100644 --- a/include/linux/srcutree.h +++ b/include/linux/srcutree.h @@ -40,7 +40,7 @@ struct srcu_data { unsigned long srcu_unlock_count[2]; /* Unlocks per CPU. */ /* Update-side state. */ - raw_spinlock_t __private lock ____cacheline_internodealigned_in_smp; + spinlock_t __private lock ____cacheline_internodealigned_in_smp; struct rcu_segcblist srcu_cblist; /* List of callbacks.*/ unsigned long srcu_gp_seq_needed; /* Furthest future GP needed. */ unsigned long srcu_gp_seq_needed_exp; /* Furthest future exp GP. */ @@ -58,7 +58,7 @@ struct srcu_data { * Node in SRCU combining tree, similar in function to rcu_data. */ struct srcu_node { - raw_spinlock_t __private lock; + spinlock_t __private lock; unsigned long srcu_have_cbs[4]; /* GP seq for children */ /* having CBs, but only */ /* is > ->srcu_gq_seq. */ @@ -78,7 +78,7 @@ struct srcu_struct { struct srcu_node *level[RCU_NUM_LVLS + 1]; /* First node at each level. */ struct mutex srcu_cb_mutex; /* Serialize CB preparation. */ - raw_spinlock_t __private lock; /* Protect counters */ + spinlock_t __private lock; /* Protect counters */ struct mutex srcu_gp_mutex; /* Serialize GP work. */ unsigned int srcu_idx; /* Current rdr array element. */ unsigned long srcu_gp_seq; /* Grace-period seq #. */ @@ -107,7 +107,7 @@ struct srcu_struct { #define __SRCU_STRUCT_INIT(name) \ { \ .sda = &name##_srcu_data, \ - .lock = __RAW_SPIN_LOCK_UNLOCKED(name.lock), \ + .lock = __SPIN_LOCK_UNLOCKED(name.lock), \ .srcu_gp_seq_needed = 0 - 1, \ __SRCU_DEP_MAP_INIT(name) \ } -- cgit v1.2.3