From: Willy Tarreau <w@1wt.eu>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org,
        linux@roeck-us.net
Cc: Rabin Vincent <rabinv@axis.com>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Steven Rostedt <rostedt@goodmis.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@kernel.org>,
        Nikolay Borisov <n.borisov.lkml@gmail.com>,
        Jiri Slaby <jslaby@suse.cz>, Willy Tarreau <w@1wt.eu>
Subject: [PATCH 3.10 142/268] sched/debug: Don't dump sched debug info in SysRq-W
Date: Mon, 19 Jun 2017 20:30:41 +0200
Message-Id: <1497897167-14556-143-git-send-email-w@1wt.eu>
In-Reply-To: <1497897167-14556-1-git-send-email-w@1wt.eu>
References: <1497897167-14556-1-git-send-email-w@1wt.eu>
Sender: linux-kernel-owner@vger.kernel.org

From: Rabin Vincent <rabinv@axis.com>

commit fb90a6e93c0684ab2629a42462400603aa829b9c upstream.

sysrq_sched_debug_show() can dump a lot of information.  Don't print out
all that if we're just trying to get a list of blocked tasks (SysRq-W).
The information is still accessible with SysRq-T.

Signed-off-by: Rabin Vincent <rabinv@axis.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1459777322-30902-1-git-send-email-rabin.vincent@axis.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Nikolay Borisov <n.borisov.lkml@gmail.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Willy Tarreau <w@1wt.eu>
---
 kernel/sched/core.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 506e56e..0892cfa 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -4745,7 +4745,8 @@ void show_state_filter(unsigned long state_filter)
 	touch_all_softlockup_watchdogs();
 
 #ifdef CONFIG_SCHED_DEBUG
-	sysrq_sched_debug_show();
+	if (!state_filter)
+		sysrq_sched_debug_show();
 #endif
 	rcu_read_unlock();
 	/*
-- 
2.8.0.rc2.1.gbe9624a