lkml.org 
[lkml]   [2022]   [Aug]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] sched/debug: avoid executing show_state and causing rcu stall warning
Date
From: Liu Song <liusong@linux.alibaba.com>

If the number of CPUs is large, "sysrq_sched_debug_show" will execute for
a long time. Every time I execute "echo t > /proc/sysrq-trigger" on my
128-core machine, the rcu stall warning will be triggered. Moreover,
sysrq_sched_debug_show does not need to be protected by rcu_read_lock,
and no rcu stall warning will appear after adjustment.

Signed-off-by: Liu Song <liusong@linux.alibaba.com>
---
kernel/sched/core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 5555e49..82c117e 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -8879,11 +8879,11 @@ void show_state_filter(unsigned int state_filter)
sched_show_task(p);
}

+ rcu_read_unlock();
#ifdef CONFIG_SCHED_DEBUG
if (!state_filter)
sysrq_sched_debug_show();
#endif
- rcu_read_unlock();
/*
* Only show locks if all tasks are dumped:
*/
--
1.8.3.1
\
 
 \ /
  Last update: 2022-08-03 03:20    [W:0.076 / U:5.840 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site