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-rw-r--r--kernel/rcu/srcutree.c20
1 files changed, 13 insertions, 7 deletions
diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c
index 50ba70f019de..0db7873f4e95 100644
--- a/kernel/rcu/srcutree.c
+++ b/kernel/rcu/srcutree.c
@@ -513,7 +513,7 @@ static bool srcu_readers_active(struct srcu_struct *ssp)
#define SRCU_INTERVAL 1 // Base delay if no expedited GPs pending.
#define SRCU_MAX_INTERVAL 10 // Maximum incremental delay from slow readers.
-#define SRCU_MAX_NODELAY_PHASE 1 // Maximum per-GP-phase consecutive no-delay instances.
+#define SRCU_MAX_NODELAY_PHASE 3 // Maximum per-GP-phase consecutive no-delay instances.
#define SRCU_MAX_NODELAY 100 // Maximum consecutive no-delay instances.
/*
@@ -522,16 +522,22 @@ static bool srcu_readers_active(struct srcu_struct *ssp)
*/
static unsigned long srcu_get_delay(struct srcu_struct *ssp)
{
+ unsigned long gpstart;
+ unsigned long j;
unsigned long jbase = SRCU_INTERVAL;
if (ULONG_CMP_LT(READ_ONCE(ssp->srcu_gp_seq), READ_ONCE(ssp->srcu_gp_seq_needed_exp)))
jbase = 0;
- if (rcu_seq_state(READ_ONCE(ssp->srcu_gp_seq)))
- jbase += jiffies - READ_ONCE(ssp->srcu_gp_start);
- if (!jbase) {
- WRITE_ONCE(ssp->srcu_n_exp_nodelay, READ_ONCE(ssp->srcu_n_exp_nodelay) + 1);
- if (READ_ONCE(ssp->srcu_n_exp_nodelay) > SRCU_MAX_NODELAY_PHASE)
- jbase = 1;
+ if (rcu_seq_state(READ_ONCE(ssp->srcu_gp_seq))) {
+ j = jiffies - 1;
+ gpstart = READ_ONCE(ssp->srcu_gp_start);
+ if (time_after(j, gpstart))
+ jbase += j - gpstart;
+ if (!jbase) {
+ WRITE_ONCE(ssp->srcu_n_exp_nodelay, READ_ONCE(ssp->srcu_n_exp_nodelay) + 1);
+ if (READ_ONCE(ssp->srcu_n_exp_nodelay) > SRCU_MAX_NODELAY_PHASE)
+ jbase = 1;
+ }
}
return jbase > SRCU_MAX_INTERVAL ? SRCU_MAX_INTERVAL : jbase;
}