Commit-ID: 21d0d79ab051bf9facb9960a30e58b93a31c75a5
Gitweb: https://git.kernel.org/tip/21d0d79ab051bf9facb9960a30e58b93a31c75a5
Author: Paul E. McKenney <paulmck@xxxxxxxxxxxxx>
AuthorDate: Fri, 11 Jan 2019 20:36:45 -0800
Committer: Paul E. McKenney <paulmck@xxxxxxxxxxxxx>
CommitDate: Tue, 26 Mar 2019 14:40:13 -0700
rcu: Inline RCU task stall-warning helper functions
The rcu_print_detail_task_stall(), rcu_print_task_stall_begin(), and
rcu_print_task_stall_end() functions were defined to allow long-gone
Kconfig options to provide an abbreviated RCU CPU stall warning printout.
This commit saves a few lines of code by inlining them into their sole
callers.
While in the area, a useless call of rcu_print_detail_task_stall_rnp()
on the root rcu_node structure was eliminated. If there is only one
rcu_node structure, its tasks get printed twice, but if there are more,
the root rcu_node structure is guaranteed to have an empty list of blocked
tasks, hence the uselessness. (Long ago, root rcu_node structures with
non-empty ->blkd_tasks lists could happen, but no longer.)
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxx>
---
kernel/rcu/tree.h | 1 -
kernel/rcu/tree_stall.h | 36 +++++++-----------------------------
2 files changed, 7 insertions(+), 30 deletions(-)
diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
index 3c4e26fff806..c6df9a13dd06 100644
--- a/kernel/rcu/tree.h
+++ b/kernel/rcu/tree.h
@@ -445,7 +445,6 @@ static void rcu_dynticks_task_enter(void);
static void rcu_dynticks_task_exit(void);
/* Forward declarations for tree_stall.h */
-static void rcu_print_detail_task_stall(void);
static int rcu_print_task_stall(struct rcu_node *rnp);
static void record_gp_stall_check_time(void);
static void check_cpu_stall(struct rcu_data *rdp);
diff --git a/kernel/rcu/tree_stall.h b/kernel/rcu/tree_stall.h
index e0e73f493363..b476786b8ef7 100644
--- a/kernel/rcu/tree_stall.h
+++ b/kernel/rcu/tree_stall.h
@@ -94,30 +94,6 @@ static void rcu_print_detail_task_stall_rnp(struct rcu_node *rnp)
raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
}
-/*
- * Dump detailed information for all tasks blocking the current RCU
- * grace period.
- */
-static void rcu_print_detail_task_stall(void)
-{
- struct rcu_node *rnp = rcu_get_root();
-
- rcu_print_detail_task_stall_rnp(rnp);
- rcu_for_each_leaf_node(rnp)
- rcu_print_detail_task_stall_rnp(rnp);
-}
-
-static void rcu_print_task_stall_begin(struct rcu_node *rnp)
-{
- pr_err("\tTasks blocked on level-%d rcu_node (CPUs %d-%d):",
- rnp->level, rnp->grplo, rnp->grphi);
-}
-
-static void rcu_print_task_stall_end(void)
-{
- pr_cont("\n");
-}
-
/*
* Scan the current list of tasks blocked within RCU read-side critical
* sections, printing out the tid of each.
@@ -129,14 +105,15 @@ static int rcu_print_task_stall(struct rcu_node *rnp)
if (!rcu_preempt_blocked_readers_cgp(rnp))
return 0;
- rcu_print_task_stall_begin(rnp);
+ pr_err("\tTasks blocked on level-%d rcu_node (CPUs %d-%d):",
+ rnp->level, rnp->grplo, rnp->grphi);
t = list_entry(rnp->gp_tasks->prev,
struct task_struct, rcu_node_entry);
list_for_each_entry_continue(t, &rnp->blkd_tasks, rcu_node_entry) {
pr_cont(" P%d", t->pid);
ndetected++;
}
- rcu_print_task_stall_end();
+ pr_cont("\n");
return ndetected;
}
@@ -146,7 +123,7 @@ static int rcu_print_task_stall(struct rcu_node *rnp)
* Because preemptible RCU does not exist, we never have to check for
* tasks blocked within RCU read-side critical sections.
*/
-static void rcu_print_detail_task_stall(void)
+static void rcu_print_detail_task_stall_rnp(struct rcu_node *rnp)
{
}
@@ -253,7 +230,7 @@ static void print_other_cpu_stall(unsigned long gp_seq)
unsigned long gpa;
unsigned long j;
int ndetected = 0;
- struct rcu_node *rnp = rcu_get_root();
+ struct rcu_node *rnp;
long totqlen = 0;
/* Kick and suppress, if so configured. */
@@ -291,7 +268,8 @@ static void print_other_cpu_stall(unsigned long gp_seq)
rcu_dump_cpu_stacks();
/* Complain about tasks blocking the grace period. */
- rcu_print_detail_task_stall();
+ rcu_for_each_leaf_node(rnp)
+ rcu_print_detail_task_stall_rnp(rnp);
} else {
if (rcu_seq_current(&rcu_state.gp_seq) != gp_seq) {
pr_err("INFO: Stall ended before state dump start\n");
|