Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

[mirror_ubuntu-bionic-kernel.git] / kernel / rcu / rcutorture.c

diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 96a3cdaeed9155df0c9dff341ca090acd9dfdf6c..74f6b0146b9878f3b9d42dd85b6bd1924be08387 100644 (file)
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -51,6 +51,7 @@
 #include <asm/byteorder.h>
 #include <linux/torture.h>
 #include <linux/vmalloc.h>
+#include <linux/sched/debug.h>
 
 #include "rcu.h"
 
@@ -89,6 +90,7 @@ torture_param(int, shutdown_secs, 0, "Shutdown time (s), <= zero to disable.");
 torture_param(int, stall_cpu, 0, "Stall duration (s), zero to disable.");
 torture_param(int, stall_cpu_holdoff, 10,
             "Time to wait before starting stall (s).");
+torture_param(int, stall_cpu_irqsoff, 0, "Disable interrupts while stalling.");
 torture_param(int, stat_interval, 60,
             "Number of seconds between stats printk()s");
 torture_param(int, stutter, 5, "Number of seconds to run/halt test");
@@ -1239,6 +1241,7 @@ rcu_torture_stats_print(void)
        long pipesummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 };
        long batchsummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 };
        static unsigned long rtcv_snap = ULONG_MAX;
+       static bool splatted;
        struct task_struct *wtp;
 
        for_each_possible_cpu(cpu) {
@@ -1324,6 +1327,10 @@ rcu_torture_stats_print(void)
                         gpnum, completed, flags,
                         wtp == NULL ? ~0UL : wtp->state,
                         wtp == NULL ? -1 : (int)task_cpu(wtp));
+               if (!splatted && wtp) {
+                       sched_show_task(wtp);
+                       splatted = true;
+               }
                show_rcu_gp_kthreads();
                rcu_ftrace_dump(DUMP_ALL);
        }
@@ -1357,7 +1364,7 @@ rcu_torture_print_module_parms(struct rcu_torture_ops *cur_ops, const char *tag)
                 "fqs_duration=%d fqs_holdoff=%d fqs_stutter=%d "
                 "test_boost=%d/%d test_boost_interval=%d "
                 "test_boost_duration=%d shutdown_secs=%d "
-                "stall_cpu=%d stall_cpu_holdoff=%d "
+                "stall_cpu=%d stall_cpu_holdoff=%d stall_cpu_irqsoff=%d "
                 "n_barrier_cbs=%d "
                 "onoff_interval=%d onoff_holdoff=%d\n",
                 torture_type, tag, nrealreaders, nfakewriters,
@@ -1365,7 +1372,7 @@ rcu_torture_print_module_parms(struct rcu_torture_ops *cur_ops, const char *tag)
                 stutter, irqreader, fqs_duration, fqs_holdoff, fqs_stutter,
                 test_boost, cur_ops->can_boost,
                 test_boost_interval, test_boost_duration, shutdown_secs,
-                stall_cpu, stall_cpu_holdoff,
+                stall_cpu, stall_cpu_holdoff, stall_cpu_irqsoff,
                 n_barrier_cbs,
                 onoff_interval, onoff_holdoff);
 }
@@ -1430,12 +1437,19 @@ static int rcu_torture_stall(void *args)
        if (!kthread_should_stop()) {
                stop_at = get_seconds() + stall_cpu;
                /* RCU CPU stall is expected behavior in following code. */
-               pr_alert("rcu_torture_stall start.\n");
                rcu_read_lock();
-               preempt_disable();
+               if (stall_cpu_irqsoff)
+                       local_irq_disable();
+               else
+                       preempt_disable();
+               pr_alert("rcu_torture_stall start on CPU %d.\n",
+                        smp_processor_id());
                while (ULONG_CMP_LT(get_seconds(), stop_at))
                        continue;  /* Induce RCU CPU stall warning. */
-               preempt_enable();
+               if (stall_cpu_irqsoff)
+                       local_irq_enable();
+               else
+                       preempt_enable();
                rcu_read_unlock();
                pr_alert("rcu_torture_stall end.\n");
        }