linux_dsm_epyc7002/include
Frederic Weisbecker e713bdd791 rcu/nocb: Perform deferred wake up before last idle's need_resched() check
commit 43789ef3f7d61aa7bed0cb2764e588fc990c30ef upstream.

Entering RCU idle mode may cause a deferred wake up of an RCU NOCB_GP
kthread (rcuog) to be serviced.

Usually a local wake up happening while running the idle task is handled
in one of the need_resched() checks carefully placed within the idle
loop that can break to the scheduler.

Unfortunately the call to rcu_idle_enter() is already beyond the last
generic need_resched() check and we may halt the CPU with a resched
request unhandled, leaving the task hanging.

Fix this with splitting the rcuog wakeup handling from rcu_idle_enter()
and place it before the last generic need_resched() check in the idle
loop. It is then assumed that no call to call_rcu() will be performed
after that in the idle loop until the CPU is put in low power mode.

Fixes: 96d3fd0d31 (rcu: Break call_rcu() deadlock involving scheduler and perf)
Reported-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20210131230548.32970-3-frederic@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-04 11:38:35 +01:00
..
acpi ACPICA: Fix exception code class checks 2021-03-04 11:37:24 +01:00
asm-generic vmlinux.lds.h: Define SANTIZER_DISCARDS with CONFIG_GCOV_KERNEL=y 2021-03-04 11:37:19 +01:00
clocksource
crypto
drm drm/dp/mst: Export drm_dp_get_vc_payload_bw() 2021-02-10 09:29:18 +01:00
dt-bindings ASoC: dt-bindings: lpass: Fix and common up lpass dai ids 2021-02-03 23:28:46 +01:00
keys
kunit kunit: fix display of failed expectations for strings 2020-11-10 13:45:15 -07:00
kvm ARM: 2020-10-23 11:17:56 -07:00
linux rcu/nocb: Perform deferred wake up before last idle's need_resched() check 2021-03-04 11:38:35 +01:00
math-emu
media media: v4l2-fwnode: v4l2_fwnode_endpoint_parse caller must init vep argument 2020-12-30 11:53:11 +01:00
memory
misc
net tcp: fix SO_RCVLOWAT related hangs under mem pressure 2021-03-04 11:37:33 +01:00
pcmcia
ras mm,hwpoison: introduce MF_MSG_UNSPLIT_THP 2020-10-16 11:11:17 -07:00
rdma RDMA: Lift ibdev_to_node from rds to common code 2021-02-26 10:12:59 +01:00
scsi scsi: libiscsi: Fix NOP race condition 2020-11-16 22:32:50 -05:00
soc net: dsa: felix: implement port flushing on .phylink_mac_link_down 2021-02-17 11:02:27 +01:00
sound ASoC: Fixes for v5.11 2020-11-19 19:56:29 +01:00
target
trace trace: fix potenial dangerous pointer 2020-11-25 13:03:44 +01:00
uapi drm/fourcc: fix Amlogic format modifier masks 2021-03-04 11:37:38 +01:00
vdso
video gpu: ipu-v3: remove unused functions 2020-10-26 10:42:38 +01:00
xen Xen/gntdev: correct error checking in gntdev_map_grant_pages() 2021-02-23 15:53:24 +01:00