[Devel] [PATCH RHEL COMMIT] sched: disable dumping cfs info on sysrq trigger

[Konstantin Khorenko]

The commit is pushed to "branch-rh9-5.14.vz9.1.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after ark-5.14
------>
commit 0d4898e492bf774bead9feeea709876316ec9083
Author: Kirill Tkhai <ktkhai at virtuozzo.com>
Date:   Fri Sep 24 14:49:27 2021 +0300

    sched: disable dumping cfs info on sysrq trigger
    
    This results in soft lockups, because it writes too much data to
    console. At the same time information it shows is only useful for sched
    debugging and can be obtained via /proc/sched_debug anyway. Besides, it
    is disabled in PCS6. So disable it in vz7 either.
    
    https://jira.sw.ru/browse/PSBM-41140
    
    Signed-off-by: Vladimir Davydov <vdavydov at virtuozzo.com>
    Signed-off-by: Kirill Tkhai <ktkhai at virtuozzo.com>
    
    https://jira.sw.ru/browse/PSBM-133986
    
    (cherry picked from commit e8da25d0fa103932b782bdc59e99013f610badfc)
    Signed-off-by: Alexander Mikhalitsyn <alexander.mikhalitsyn at virtuozzo.com>
---
 kernel/sched/core.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 2a9ca0492df4..bdff24034916 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -8278,8 +8278,16 @@ void show_state_filter(unsigned int state_filter)
 	}
 
 #ifdef CONFIG_SCHED_DEBUG
+#ifndef CONFIG_VE
+	/*
+	 * This results in soft lockups, because it writes too much data to
+	 * console. At the same time information it shows is only useful for
+	 * sched debugging and can be obtained via /proc/sched_debug anyway.
+	 * So disable it.
+	 */
 	if (!state_filter)
 		sysrq_sched_debug_show();
+#endif
 #endif
 	rcu_read_unlock();
 	/*