This is a note to let you know that I've just added the patch titled

sched/core: Add missing update_rq_clock() call in sched_move_task()

to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: sched-core-add-missing-update_rq_clock-call-in-sched_move_task.patch and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From foo@baz Thu Nov 9 09:48:01 CET 2017

From: Peter Zijlstra peterz@infradead.org Date: Mon, 23 Jan 2017 16:05:55 +0100 Subject: sched/core: Add missing update_rq_clock() call in sched_move_task()

From: Peter Zijlstra peterz@infradead.org

[ Upstream commit 1b1d62254df0fe42a711eb71948f915918987790 ]

Bug was noticed via this warning:

WARNING: CPU: 6 PID: 1 at kernel/sched/sched.h:804 detach_task_cfs_rq+0x8e8/0xb80 rq->clock_update_flags < RQCF_ACT_SKIP Modules linked in: CPU: 6 PID: 1 Comm: systemd Not tainted 4.10.0-rc5-00140-g0874170baf55-dirty #1 Hardware name: Supermicro SYS-4048B-TRFT/X10QBi, BIOS 1.0 04/11/2014 Call Trace: dump_stack+0x4d/0x65 __warn+0xcb/0xf0 warn_slowpath_fmt+0x5f/0x80 detach_task_cfs_rq+0x8e8/0xb80 ? allocate_cgrp_cset_links+0x59/0x80 task_change_group_fair+0x27/0x150 sched_change_group+0x48/0xf0 sched_move_task+0x53/0x150 cpu_cgroup_attach+0x36/0x70 cgroup_taskset_migrate+0x175/0x300 cgroup_migrate+0xab/0xd0 cgroup_attach_task+0xf0/0x190 __cgroup_procs_write+0x1ed/0x2f0 cgroup_procs_write+0x14/0x20 cgroup_file_write+0x3f/0x100 kernfs_fop_write+0x104/0x180 __vfs_write+0x37/0x140 vfs_write+0xb8/0x1b0 SyS_write+0x55/0xc0 do_syscall_64+0x61/0x170 entry_SYSCALL64_slow_path+0x25/0x25

Reported-by: Ingo Molnar mingo@kernel.org Reported-by: Borislav Petkov bp@alien8.de Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Cc: Linus Torvalds torvalds@linux-foundation.org Cc: Mike Galbraith efault@gmx.de Cc: Peter Zijlstra peterz@infradead.org Cc: Thomas Gleixner tglx@linutronix.de Signed-off-by: Ingo Molnar mingo@kernel.org Signed-off-by: Sasha Levin alexander.levin@verizon.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- kernel/sched/core.c | 1 + 1 file changed, 1 insertion(+)

--- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -7961,6 +7961,7 @@ void sched_move_task(struct task_struct struct rq *rq;

rq = task_rq_lock(tsk, &rf); + update_rq_clock(rq);

running = task_current(rq, tsk); queued = task_on_rq_queued(tsk);

Patches currently in stable-queue which might be from peterz@infradead.org are

queue-4.9/sched-core-add-missing-update_rq_clock-call-in-sched_move_task.patch queue-4.9/sched-cputime-powerpc32-fix-stale-scaled-stime-on-context-switch.patch