From: "Paul E. McKenney" paulmck@kernel.org
stable inclusion from stable-5.10.65 commit ea5e5bc881a4de9b5e09a16af950af2584dd67d2 bugzilla: 182361 https://gitee.com/openeuler/kernel/issues/I4EH3U
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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[ Upstream commit a649d25dcc671a33b9cc3176411920fdc5fbd98e ]
This commit adds a number of lockdep_assert_irqs_disabled() calls to rcu_sched_clock_irq() and a number of the functions that it calls. The point of this is to help track down a situation where lockdep appears to be insisting that interrupts are enabled within these functions, which should only ever be invoked from the scheduling-clock interrupt handler.
Link: https://lore.kernel.org/lkml/20201111133813.GA81547@elver.google.com/ Signed-off-by: Paul E. McKenney paulmck@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Chen Jun chenjun102@huawei.com Acked-by: Weilong Chen chenweilong@huawei.com
Signed-off-by: Chen Jun chenjun102@huawei.com --- kernel/rcu/tree.c | 4 ++++ kernel/rcu/tree_plugin.h | 1 + kernel/rcu/tree_stall.h | 8 ++++++++ 3 files changed, 13 insertions(+)
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 8c3ba0185082..8c81c05c4236 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -2561,6 +2561,7 @@ static void rcu_do_batch(struct rcu_data *rdp) void rcu_sched_clock_irq(int user) { trace_rcu_utilization(TPS("Start scheduler-tick")); + lockdep_assert_irqs_disabled(); raw_cpu_inc(rcu_data.ticks_this_gp); /* The load-acquire pairs with the store-release setting to true. */ if (smp_load_acquire(this_cpu_ptr(&rcu_data.rcu_urgent_qs))) { @@ -2574,6 +2575,7 @@ void rcu_sched_clock_irq(int user) rcu_flavor_sched_clock_irq(user); if (rcu_pending(user)) invoke_rcu_core(); + lockdep_assert_irqs_disabled();
trace_rcu_utilization(TPS("End scheduler-tick")); } @@ -3730,6 +3732,8 @@ static int rcu_pending(int user) struct rcu_data *rdp = this_cpu_ptr(&rcu_data); struct rcu_node *rnp = rdp->mynode;
+ lockdep_assert_irqs_disabled(); + /* Check for CPU stalls, if enabled. */ check_cpu_stall(rdp);
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index 7d4f78bf4057..574aeaac9272 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -682,6 +682,7 @@ static void rcu_flavor_sched_clock_irq(int user) { struct task_struct *t = current;
+ lockdep_assert_irqs_disabled(); if (user || rcu_is_cpu_rrupt_from_idle()) { rcu_note_voluntary_context_switch(current); } diff --git a/kernel/rcu/tree_stall.h b/kernel/rcu/tree_stall.h index cdfaa44ffd70..3fc21617546d 100644 --- a/kernel/rcu/tree_stall.h +++ b/kernel/rcu/tree_stall.h @@ -262,6 +262,7 @@ static int rcu_print_task_stall(struct rcu_node *rnp, unsigned long flags) struct task_struct *t; struct task_struct *ts[8];
+ lockdep_assert_irqs_disabled(); if (!rcu_preempt_blocked_readers_cgp(rnp)) return 0; pr_err("\tTasks blocked on level-%d rcu_node (CPUs %d-%d):", @@ -286,6 +287,7 @@ static int rcu_print_task_stall(struct rcu_node *rnp, unsigned long flags) ".q"[rscr.rs.b.need_qs], ".e"[rscr.rs.b.exp_hint], ".l"[rscr.on_blkd_list]); + lockdep_assert_irqs_disabled(); put_task_struct(t); ndetected++; } @@ -474,6 +476,8 @@ static void print_other_cpu_stall(unsigned long gp_seq, unsigned long gps) struct rcu_node *rnp; long totqlen = 0;
+ lockdep_assert_irqs_disabled(); + /* Kick and suppress, if so configured. */ rcu_stall_kick_kthreads(); if (rcu_stall_is_suppressed()) @@ -495,6 +499,7 @@ static void print_other_cpu_stall(unsigned long gp_seq, unsigned long gps) } } ndetected += rcu_print_task_stall(rnp, flags); // Releases rnp->lock. + lockdep_assert_irqs_disabled(); }
for_each_possible_cpu(cpu) @@ -540,6 +545,8 @@ static void print_cpu_stall(unsigned long gps) struct rcu_node *rnp = rcu_get_root(); long totqlen = 0;
+ lockdep_assert_irqs_disabled(); + /* Kick and suppress, if so configured. */ rcu_stall_kick_kthreads(); if (rcu_stall_is_suppressed()) @@ -594,6 +601,7 @@ static void check_cpu_stall(struct rcu_data *rdp) unsigned long js; struct rcu_node *rnp;
+ lockdep_assert_irqs_disabled(); if ((rcu_stall_is_suppressed() && !READ_ONCE(rcu_kick_kthreads)) || !rcu_gp_in_progress()) return;