xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

rcu: Add more tracing of expedited grace periods

Browse Source 
This commit adds more tracing of expedited grace periods to enable
improved debugging of slowdowns.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit is contained in:
Paul E. McKenney
2018-01-31 19:23:24 -08:00
parent 274afd6bfa
commit 9a414201ae
3 changed files with 22 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

12
kernel/rcu/tree_exp.h
View File

@@ -28,6 +28,15 @@ static void rcu_exp_gp_seq_start(struct rcu_state *rsp)
rcu_seq_start(&rsp->expedited_sequence);
}
/*
* Return then value that expedited-grace-period counter will have
* at the end of the current grace period.
*/
static unsigned long rcu_exp_gp_seq_endval(struct rcu_state *rsp)
{
return rcu_seq_endval(&rsp->expedited_sequence);
}
/*
* Record the end of an expedited grace period.
*/
@@ -366,7 +375,9 @@ static void sync_rcu_exp_select_cpus(struct rcu_state *rsp,
int ret;
struct rcu_node *rnp;
trace_rcu_exp_grace_period(rsp->name, rcu_exp_gp_seq_endval(rsp), TPS("reset"));
sync_exp_reset_tree(rsp);
trace_rcu_exp_grace_period(rsp->name, rcu_exp_gp_seq_endval(rsp), TPS("select"));
rcu_for_each_leaf_node(rsp, rnp) {
raw_spin_lock_irqsave_rcu_node(rnp, flags);
@@ -443,6 +454,7 @@ static void synchronize_sched_expedited_wait(struct rcu_state *rsp)
struct rcu_node *rnp_root = rcu_get_root(rsp);
int ret;
trace_rcu_exp_grace_period(rsp->name, rcu_exp_gp_seq_endval(rsp), TPS("startwait"));
jiffies_stall = rcu_jiffies_till_stall_check();
jiffies_start = jiffies;