We are going to try split the rcu kthread into few kthread works.
We will not stay in the funciton all the time and "first_gp_fqs"
variable will not preserve the state. Let's store it into
struct rcu_state.
Note that this change is needed only when the split into more
kthread works is accepted.
The patch does not change the existing behavior.
Signed-off-by: Petr Mladek <pmladek@xxxxxxxx>
---
kernel/rcu/tree.c | 11 +++++------
kernel/rcu/tree.h | 2 ++
2 files changed, 7 insertions(+), 6 deletions(-)
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 5413d87a67c6..5a3e70a21df8 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -1927,7 +1927,7 @@ static bool rcu_gp_fqs_check_wake(struct rcu_state *rsp, int *gfp)
/*
* Do one round of quiescent-state forcing.
*/
-static void rcu_gp_fqs(struct rcu_state *rsp, bool first_time)
+static void rcu_gp_fqs(struct rcu_state *rsp)
{
bool isidle = false;
unsigned long maxj;
@@ -1935,7 +1935,7 @@ static void rcu_gp_fqs(struct rcu_state *rsp, bool first_time)
WRITE_ONCE(rsp->gp_activity, jiffies);
rsp->n_force_qs++;
- if (first_time) {
+ if (rsp->first_gp_fqs) {
/* Collect dyntick-idle snapshots. */
if (is_sysidle_rcu_state(rsp)) {
isidle = true;
@@ -1944,6 +1944,7 @@ static void rcu_gp_fqs(struct rcu_state *rsp, bool first_time)
force_qs_rnp(rsp, dyntick_save_progress_counter,
&isidle, &maxj);
rcu_sysidle_report_gp(rsp, isidle, maxj);
+ rsp->first_gp_fqs = false;
} else {
/* Handle dyntick-idle and offline CPUs. */
isidle = true;
@@ -2038,7 +2039,6 @@ static void rcu_gp_cleanup(struct rcu_state *rsp)
*/
static int __noreturn rcu_gp_kthread(void *arg)
{
- bool first_gp_fqs;
int gf;
unsigned long j;
int ret;
@@ -2070,7 +2070,7 @@ static int __noreturn rcu_gp_kthread(void *arg)
}
/* Handle quiescent-state forcing. */
- first_gp_fqs = true;
+ rsp->first_gp_fqs = true;
j = jiffies_till_first_fqs;
if (j > HZ) {
j = HZ;
@@ -2098,8 +2098,7 @@ static int __noreturn rcu_gp_kthread(void *arg)
trace_rcu_grace_period(rsp->name,
READ_ONCE(rsp->gpnum),
TPS("fqsstart"));
- rcu_gp_fqs(rsp, first_gp_fqs);
- first_gp_fqs = false;
+ rcu_gp_fqs(rsp);
trace_rcu_grace_period(rsp->name,
READ_ONCE(rsp->gpnum),
TPS("fqsend"));
diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
index de370b611837..f16578a5eefe 100644
--- a/kernel/rcu/tree.h
+++ b/kernel/rcu/tree.h
@@ -470,6 +470,8 @@ struct rcu_state {
wait_queue_head_t gp_wq; /* Where GP task waits. */
short gp_flags; /* Commands for GP task. */
short gp_state; /* GP kthread sleep state. */
+ bool first_gp_fqs; /* Do we force QS for */
+ /* the first time? */
/* End of fields guarded by root rcu_node's lock. */
--
1.8.5.6
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