linux/arch/s390
Qian Cai de5d9dae15 s390/smp: move rcu_cpu_starting() earlier
The call to rcu_cpu_starting() in smp_init_secondary() is not early
enough in the CPU-hotplug onlining process, which results in lockdep
splats as follows:

 WARNING: suspicious RCU usage
 -----------------------------
 kernel/locking/lockdep.c:3497 RCU-list traversed in non-reader section!!

 other info that might help us debug this:

 RCU used illegally from offline CPU!
 rcu_scheduler_active = 1, debug_locks = 1
 no locks held by swapper/1/0.

 Call Trace:
 show_stack+0x158/0x1f0
 dump_stack+0x1f2/0x238
 __lock_acquire+0x2640/0x4dd0
 lock_acquire+0x3a8/0xd08
 _raw_spin_lock_irqsave+0xc0/0xf0
 clockevents_register_device+0xa8/0x528
 init_cpu_timer+0x33e/0x468
 smp_init_secondary+0x11a/0x328
 smp_start_secondary+0x82/0x88

This is avoided by moving the call to rcu_cpu_starting up near the
beginning of the smp_init_secondary() function. Note that the
raw_smp_processor_id() is required in order to avoid calling into
lockdep before RCU has declared the CPU to be watched for readers.

Link: https://lore.kernel.org/lkml/160223032121.7002.1269740091547117869.tip-bot2@tip-bot2/
Signed-off-by: Qian Cai <cai@redhat.com>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-03 15:12:16 +01:00
..
appldata s390/appldata: use struct_size() helper 2020-06-29 16:32:34 +02:00
boot treewide: Convert macro and uses of __section(foo) to __section("foo") 2020-10-25 14:51:49 -07:00
configs s390: update defconfigs 2020-11-03 15:12:16 +01:00
crypto mm, treewide: rename kzfree() to kfree_sensitive() 2020-08-07 11:33:22 -07:00
hypfs fs_parse: fold fs_parameter_desc/fs_parameter_spec 2020-02-07 14:48:37 -05:00
include s390/vdso: remove empty unused file 2020-11-03 15:12:15 +01:00
kernel s390/smp: move rcu_cpu_starting() earlier 2020-11-03 15:12:16 +01:00
kvm mm/gup: remove task_struct pointer for all gup code 2020-08-12 10:58:04 -07:00
lib s390/lib: fix kernel doc for memcmp() 2020-10-07 21:50:01 +02:00
mm treewide: Convert macro and uses of __section(foo) to __section("foo") 2020-10-25 14:51:49 -07:00
net s390/bpf: Fix multiple tail calls 2020-09-14 18:21:31 -07:00
oprofile s390/unwind: introduce stack unwind API 2019-05-02 13:54:11 +02:00
pci VFIO updates for v5.10-rc1 2020-10-22 13:00:44 -07:00
purgatory .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
tools .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
Kbuild s390/numa: move code to arch/s390/kernel 2020-08-11 18:16:55 +02:00
Kconfig vhost,vdpa,virtio: cleanups, fixes 2020-10-23 11:00:57 -07:00
Kconfig.debug s390/mm,ptdump: convert to generic page table dumper 2020-09-14 11:38:34 +02:00
Makefile kbuild: remove cc-option test of -ffreestanding 2020-07-07 11:13:10 +09:00