This is a note to let you know that I've just added the patch titled
rcuscale: Move rcu_scale_writer() schedule_timeout_uninterruptible() to _idle()
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
rcuscale-move-rcu_scale_writer-schedule_timeout_unin.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit bc8e449cb13f7633dd7d1ff5c5303cdc5e5b727d
Author: Zqiang <qiang.zhang1211@xxxxxxxxx>
Date: Fri Jun 16 15:39:26 2023 +0800
rcuscale: Move rcu_scale_writer() schedule_timeout_uninterruptible() to _idle()
[ Upstream commit e60c122a1614b4f65b29a7bef9d83b9fd30e937a ]
The rcuscale.holdoff module parameter can be used to delay the start
of rcu_scale_writer() kthread. However, the hung-task timeout will
trigger when the timeout specified by rcuscale.holdoff is greater than
hung_task_timeout_secs:
runqemu kvm nographic slirp qemuparams="-smp 4 -m 2048M"
bootparams="rcuscale.shutdown=0 rcuscale.holdoff=300"
[ 247.071753] INFO: task rcu_scale_write:59 blocked for more than 122 seconds.
[ 247.072529] Not tainted 6.4.0-rc1-00134-gb9ed6de8d4ff #7
[ 247.073400] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 247.074331] task:rcu_scale_write state:D stack:30144 pid:59 ppid:2 flags:0x00004000
[ 247.075346] Call Trace:
[ 247.075660] <TASK>
[ 247.075965] __schedule+0x635/0x1280
[ 247.076448] ? __pfx___schedule+0x10/0x10
[ 247.076967] ? schedule_timeout+0x2dc/0x4d0
[ 247.077471] ? __pfx_lock_release+0x10/0x10
[ 247.078018] ? enqueue_timer+0xe2/0x220
[ 247.078522] schedule+0x84/0x120
[ 247.078957] schedule_timeout+0x2e1/0x4d0
[ 247.079447] ? __pfx_schedule_timeout+0x10/0x10
[ 247.080032] ? __pfx_rcu_scale_writer+0x10/0x10
[ 247.080591] ? __pfx_process_timeout+0x10/0x10
[ 247.081163] ? __pfx_sched_set_fifo_low+0x10/0x10
[ 247.081760] ? __pfx_rcu_scale_writer+0x10/0x10
[ 247.082287] rcu_scale_writer+0x6b1/0x7f0
[ 247.082773] ? mark_held_locks+0x29/0xa0
[ 247.083252] ? __pfx_rcu_scale_writer+0x10/0x10
[ 247.083865] ? __pfx_rcu_scale_writer+0x10/0x10
[ 247.084412] kthread+0x179/0x1c0
[ 247.084759] ? __pfx_kthread+0x10/0x10
[ 247.085098] ret_from_fork+0x2c/0x50
[ 247.085433] </TASK>
This commit therefore replaces schedule_timeout_uninterruptible() with
schedule_timeout_idle().
Signed-off-by: Zqiang <qiang.zhang1211@xxxxxxxxx>
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/kernel/rcu/rcuscale.c b/kernel/rcu/rcuscale.c
index 57ec414710bbc..a83cb29d37607 100644
--- a/kernel/rcu/rcuscale.c
+++ b/kernel/rcu/rcuscale.c
@@ -402,7 +402,7 @@ rcu_scale_writer(void *arg)
sched_set_fifo_low(current);
if (holdoff)
- schedule_timeout_uninterruptible(holdoff * HZ);
+ schedule_timeout_idle(holdoff * HZ);
/*
* Wait until rcu_end_inkernel_boot() is called for normal GP tests
