[Devel] [PATCH RHEL7 COMMIT] sched: disable dumping cfs info on sysrq trigger

[Konstantin Khorenko]

The commit is pushed to "branch-rh7-3.10.0-229.7.2.vz7.9.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh7-3.10.0-229.7.2.vz7.9.7
------>
commit a6d730185050bfe45a3538e6538aedac45b48d9b
Author: Vladimir Davydov <vdavydov at virtuozzo.com>
Date:   Tue Nov 10 18:10:39 2015 +0400

    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>
---
 kernel/sched/core.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 07f1090..581bfd0 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -5121,7 +5121,13 @@ void show_state_filter(unsigned long state_filter)
 
 	touch_all_softlockup_watchdogs();
 
-#ifdef CONFIG_SCHED_DEBUG
+#if 0
+	/*
+	 * 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.
+	 */
 	sysrq_sched_debug_show();
 #endif
 	rcu_read_unlock();