From: Pingfan Liu <kernelfans@xxxxxxxxx>
A grace-period sequence number contains two fields: counter and
state. SRCU_SNP_INIT_SEQ provides a guaranteed invalid value for
grace-period sequence numbers in newly allocated srcu_node structures'
->srcu_have_cbs[] and ->srcu_gp_seq_needed_exp fields. The point of the
comparison in srcu_invl_snp_seq() is not to detect invalid grace-period
sequence numbers in general, but rather to detect a newly allocated
srcu_node structure whose ->srcu_have_cbs[] and ->srcu_gp_seq_needed_exp
fields need to be brought into line with the srcu_struct structure's
->srcu_gp_seq field.
This commit therefore causes srcu_invl_snp_seq() to compare both fields
of the specified grace-period sequence number.
Signed-off-by: Pingfan Liu <kernelfans@xxxxxxxxx>
Cc: Lai Jiangshan <jiangshanlai@xxxxxxxxx>
Cc: "Paul E. McKenney" <paulmck@xxxxxxxxxx>
Cc: Josh Triplett <josh@xxxxxxxxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
Cc: <rcu@xxxxxxxxxxxxxxx>
Reviewed-by: Frederic Weisbecker <frederic@xxxxxxxxxx>
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
---
kernel/rcu/srcutree.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c
index 16953784a0bdf..6af0312005801 100644
--- a/kernel/rcu/srcutree.c
+++ b/kernel/rcu/srcutree.c
@@ -154,7 +154,7 @@ static void init_srcu_struct_data(struct srcu_struct *ssp)
*/
static inline bool srcu_invl_snp_seq(unsigned long s)
{
- return rcu_seq_state(s) == SRCU_SNP_INIT_SEQ;
+ return s == SRCU_SNP_INIT_SEQ;
}
/*
--
2.31.1.189.g2e36527f23
