98 lines
2.9 KiB
Diff
98 lines
2.9 KiB
Diff
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From: John Ogness <john.ogness@linutronix.de>
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Date: Tue, 20 Aug 2024 08:36:00 +0206
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Subject: [PATCH 34/54] rcu: Mark emergency sections in rcu stalls
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Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.11/older/patches-6.11-rt7.tar.xz
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Mark emergency sections wherever multiple lines of
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rcu stall information are generated. In an emergency
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section, every printk() call will attempt to directly
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flush to the consoles using the EMERGENCY priority.
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Signed-off-by: John Ogness <john.ogness@linutronix.de>
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Reviewed-by: Petr Mladek <pmladek@suse.com>
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Acked-by: Paul E. McKenney <paulmck@kernel.org>
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Link: https://lore.kernel.org/r/20240820063001.36405-35-john.ogness@linutronix.de
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Signed-off-by: Petr Mladek <pmladek@suse.com>
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Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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---
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kernel/rcu/tree_exp.h | 7 +++++++
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kernel/rcu/tree_stall.h | 9 +++++++++
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2 files changed, 16 insertions(+)
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--- a/kernel/rcu/tree_exp.h
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+++ b/kernel/rcu/tree_exp.h
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@@ -7,6 +7,7 @@
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* Authors: Paul E. McKenney <paulmck@linux.ibm.com>
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*/
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+#include <linux/console.h>
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#include <linux/lockdep.h>
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static void rcu_exp_handler(void *unused);
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@@ -590,6 +591,9 @@ static void synchronize_rcu_expedited_wa
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return;
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if (rcu_stall_is_suppressed())
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continue;
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+
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+ nbcon_cpu_emergency_enter();
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+
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j = jiffies;
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rcu_stall_notifier_call_chain(RCU_STALL_NOTIFY_EXP, (void *)(j - jiffies_start));
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trace_rcu_stall_warning(rcu_state.name, TPS("ExpeditedStall"));
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@@ -643,6 +647,9 @@ static void synchronize_rcu_expedited_wa
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rcu_exp_print_detail_task_stall_rnp(rnp);
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}
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jiffies_stall = 3 * rcu_exp_jiffies_till_stall_check() + 3;
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+
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+ nbcon_cpu_emergency_exit();
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+
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panic_on_rcu_stall();
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}
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}
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--- a/kernel/rcu/tree_stall.h
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+++ b/kernel/rcu/tree_stall.h
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@@ -7,6 +7,7 @@
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* Author: Paul E. McKenney <paulmck@linux.ibm.com>
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*/
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+#include <linux/console.h>
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#include <linux/kvm_para.h>
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#include <linux/rcu_notifier.h>
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@@ -605,6 +606,8 @@ static void print_other_cpu_stall(unsign
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if (rcu_stall_is_suppressed())
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return;
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+ nbcon_cpu_emergency_enter();
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+
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/*
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* OK, time to rat on our buddy...
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* See Documentation/RCU/stallwarn.rst for info on how to debug
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@@ -657,6 +660,8 @@ static void print_other_cpu_stall(unsign
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rcu_check_gp_kthread_expired_fqs_timer();
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rcu_check_gp_kthread_starvation();
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+ nbcon_cpu_emergency_exit();
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+
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panic_on_rcu_stall();
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rcu_force_quiescent_state(); /* Kick them all. */
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@@ -677,6 +682,8 @@ static void print_cpu_stall(unsigned lon
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if (rcu_stall_is_suppressed())
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return;
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+ nbcon_cpu_emergency_enter();
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+
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/*
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* OK, time to rat on ourselves...
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* See Documentation/RCU/stallwarn.rst for info on how to debug
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@@ -706,6 +713,8 @@ static void print_cpu_stall(unsigned lon
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jiffies + 3 * rcu_jiffies_till_stall_check() + 3);
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raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
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+ nbcon_cpu_emergency_exit();
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+
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panic_on_rcu_stall();
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/*
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