Paul E. McKenney 49bca2f6c7 sched: Stop resched_cpu() from sending IPIs to offline CPUs ... [ Upstream commit a0982dfa03efca6c239c52cabebcea4afb93ea6b ] The rcutorture test suite occasionally provokes a splat due to invoking resched_cpu() on an offline CPU: WARNING: CPU: 2 PID: 8 at /home/paulmck/public_git/linux-rcu/arch/x86/kernel/smp.c:128 native_smp_send_reschedule+0x37/0x40 Modules linked in: CPU: 2 PID: 8 Comm: rcu_preempt Not tainted 4.14.0-rc4+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 task: ffff902ede9daf00 task.stack: ffff96c50010c000 RIP: 0010:native_smp_send_reschedule+0x37/0x40 RSP: 0018:ffff96c50010fdb8 EFLAGS: 00010096 RAX: 000000000000002e RBX: ffff902edaab4680 RCX: 0000000000000003 RDX: 0000000080000003 RSI: 0000000000000000 RDI: 00000000ffffffff RBP: ffff96c50010fdb8 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000000 R11: 00000000299f36ae R12: 0000000000000001 R13: ffffffff9de64240 R14: 0000000000000001 R15: ffffffff9de64240 FS: 0000000000000000(0000) GS:ffff902edfc80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000f7d4c642 CR3: 000000001e0e2000 CR4: 00000000000006e0 Call Trace: resched_curr+0x8f/0x1c0 resched_cpu+0x2c/0x40 rcu_implicit_dynticks_qs+0x152/0x220 force_qs_rnp+0x147/0x1d0 ? sync_rcu_exp_select_cpus+0x450/0x450 rcu_gp_kthread+0x5a9/0x950 kthread+0x142/0x180 ? force_qs_rnp+0x1d0/0x1d0 ? kthread_create_on_node+0x40/0x40 ret_from_fork+0x27/0x40 Code: 14 01 0f 92 c0 84 c0 74 14 48 8b 05 14 4f f4 00 be fd 00 00 00 ff 90 a0 00 00 00 5d c3 89 fe 48 c7 c7 38 89 ca 9d e8 e5 56 08 00 <0f> ff 5d c3 0f 1f 44 00 00 8b 05 52 9e 37 02 85 c0 75 38 55 48 ---[ end trace 26df9e5df4bba4ac ]--- This splat cannot be generated by expedited grace periods because they always invoke resched_cpu() on the current CPU, which is good because expedited grace periods require that resched_cpu() unconditionally succeed. However, other parts of RCU can tolerate resched_cpu() acting as a no-op, at least as long as it doesn't happen too often. This commit therefore makes resched_cpu() invoke resched_curr() only if the CPU is either online or is the current CPU. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2018-03-22 09:23:27 +01:00
..
bpf	bpf: reject stores into ctx via st and xadd	2018-02-03 17:04:25 +01:00
configs	kconfig: tinyconfig: provide whole choice blocks to avoid warnings	2016-09-24 10:07:42 +02:00
debug	kdb: Fix handling of kallsyms_symbol_next() return value	2017-12-16 10:33:49 +01:00
events	bpf: one perf event close won't free bpf program attached by another perf event	2017-10-21 17:09:02 +02:00
gcov	gcov: disable for COMPILE_TEST	2018-01-23 19:50:10 +01:00
irq	genirq: Release resources in __setup_irq() error path	2017-06-26 07:13:10 +02:00
livepatch	livepatch: x86: fix relocation computation with kASLR	2015-11-11 17:36:04 +01:00
locking	locking/mutex: Allow next waiter lockless wakeup	2018-01-17 09:35:27 +01:00
power	sched/cpuset/pm: Fix cpuset vs. suspend-resume bugs	2017-10-12 11:27:35 +02:00
printk	braille-console: Fix value returned by _braille_console_setup	2018-03-22 09:23:23 +01:00
rcu	rcu: Allow for page faults in NMI handlers	2017-10-18 09:20:41 +02:00
sched	sched: Stop resched_cpu() from sending IPIs to offline CPUs	2018-03-22 09:23:27 +01:00
time	sysrq: Reset the watchdog timers while displaying high-resolution timers	2018-03-22 09:23:21 +01:00
trace	blktrace: fix unlocked registration of tracepoints	2018-02-25 11:03:35 +01:00
.gitignore	certs: add .gitignore to stop git nagging about x509_certificate_list	2015-10-21 15:18:35 +01:00
acct.c	kernel/acct.c: fix the acct->needcheck check in check_free_space()	2018-01-10 09:27:08 +01:00
async.c	kernel/async.c: revert "async: simplify lowest_in_progress()"	2018-02-16 20:09:45 +01:00
audit.c	audit: ensure that 'audit=1' actually enables audit for PID 1	2017-12-16 10:33:56 +01:00
audit.h	audit: audit_tree_match can be boolean	2015-11-04 08:23:51 -05:00
audit_fsnotify.c
audit_tree.c	audit: audit_tree_match can be boolean	2015-11-04 08:23:51 -05:00
audit_watch.c	audit: Fix use after free in audit_remove_watch_rule()	2017-08-24 17:02:35 -07:00
auditfilter.c	audit: fix comment block whitespace	2015-11-04 08:23:51 -05:00
auditsc.c	audit: fix a double fetch in audit_log_single_execve_arg()	2016-08-20 18:09:22 +02:00
backtracetest.c
bounds.c
capability.c	exec: Ensure mm->user_ns contains the execed files	2017-01-06 11:16:14 +01:00
cgroup.c	cgroup, kthread: close race window where new kthreads can be migrated to non-root cgroups	2017-04-21 09:30:04 +02:00
cgroup_freezer.c	cgroup: fix handling of multi-destination migration from subtree_control enabling	2015-12-03 10:18:21 -05:00
cgroup_pids.c	cgroup_pids: don't account for the root cgroup	2015-12-03 10:18:21 -05:00
compat.c
configs.c
context_tracking.c	context_tracking: avoid irq_save/irq_restore on guest entry and exit	2015-11-10 12:06:23 +01:00
cpu.c	stable-fixup: hotplug: fix unused function warning	2017-01-12 11:22:48 +01:00
cpu_pm.c
cpuset.c	sched/cpuset/pm: Fix cpuset vs. suspend-resume bugs	2017-10-12 11:27:35 +02:00
crash_dump.c
cred.c	cred: Reject inodes with invalid ids in set_create_file_as()	2016-09-15 08:27:49 +02:00
delayacct.c
dma.c
elfcore.c
exec_domain.c
exit.c	wait/ptrace: assume __WALL if the child is traced	2016-06-07 18:14:35 -07:00
extable.c	kernel/extable.c: mark core_kernel_text notrace	2017-07-21 07:44:56 +02:00
fork.c	kaiser: stack map PAGE_SIZE at THREAD_SIZE-PAGE_SIZE	2018-01-05 15:44:23 +01:00
freezer.c
futex.c	futex: Prevent overflow by strengthen input validation	2018-01-23 19:50:14 +01:00
futex_compat.c	ptrace: use fsuid, fsgid, effective creds for fs access checks	2016-02-25 12:01:16 -08:00
groups.c	kernel: make groups_sort calling a responsibility group_info allocators	2018-01-10 09:27:10 +01:00
hung_task.c
irq_work.c	treewide: Remove old email address	2015-11-23 09:44:58 +01:00
jump_label.c	jump_label: Invoke jump_label_test() via early_initcall()	2017-12-16 10:33:55 +01:00
kallsyms.c
kcmp.c	ptrace: use fsuid, fsgid, effective creds for fs access checks	2016-02-25 12:01:16 -08:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kexec.c	kexec: use file name as the output message prefix	2015-11-06 17:50:42 -08:00
kexec_core.c	kexec: use file name as the output message prefix	2015-11-06 17:50:42 -08:00
kexec_file.c	kexec: fix double-free when failing to relocate the purgatory	2016-09-24 10:07:36 +02:00
kexec_internal.h
kmod.c	kmod: don't run async usermode helper as a child of kworker thread	2015-10-23 17:55:10 +09:00
kprobes.c	tracing/kprobes: Enforce kprobes teardown after testing	2017-05-25 14:30:17 +02:00
ksysfs.c
kthread.c	cgroup, kthread: close race window where new kthreads can be migrated to non-root cgroups	2017-04-21 09:30:04 +02:00
latencytop.c
Makefile
membarrier.c	Fix: Disable sys_membarrier when nohz_full is enabled	2017-03-12 06:37:26 +01:00
memremap.c	mm: fix devm_memremap_pages crash, use mem_hotplug_{begin, done}	2017-01-19 20:17:18 +01:00
module-internal.h
module.c	module/retpoline: Warn about missing retpoline in module	2018-02-25 11:03:52 +01:00
module_signing.c	KEYS: Merge the type-specific data with the payload data	2015-10-21 15:18:36 +01:00
notifier.c
nsproxy.c
padata.c	padata: free correct variable	2017-05-20 14:27:02 +02:00
panic.c	kernel/panic.c: add missing \n	2017-07-05 14:37:19 +02:00
params.c	Nothing exciting, minor tweaks and cleanups.	2015-11-09 15:53:39 -08:00
pid.c	pids: make task_tgid_nr_ns() safe	2017-08-24 17:02:36 -07:00
pid_namespace.c	pid_ns: Sleep in TASK_INTERRUPTIBLE in zap_pid_ns_processes	2017-05-25 14:30:11 +02:00
profile.c	profile: hide unused functions when !CONFIG_PROC_FS	2018-02-25 11:03:44 +01:00
ptrace.c	ptrace: Properly initialize ptracer_cred on fork	2017-06-14 13:16:20 +02:00
range.c
reboot.c
relay.c
resource.c	/proc/iomem: only expose physical resource addresses to privileged users	2017-08-06 19:19:42 -07:00
seccomp.c	seccomp: fix the usage of get/put_seccomp_filter() in seccomp_get_filter()	2017-10-05 09:41:46 +02:00
signal.c	kernel/signal.c: remove the no longer needed SIGNAL_UNKILLABLE check in complete_signal()	2018-01-10 09:27:11 +01:00
smp.c	mm, page_alloc: distinguish between being unable to sleep, unwilling to sleep and avoiding waking kswapd	2015-11-06 17:50:42 -08:00
smpboot.c	stop_machine: Kill smp_hotplug_thread->pre_unpark, introduce stop_machine_unpark()	2015-10-20 10:23:55 +02:00
smpboot.h
softirq.c
stacktrace.c
stop_machine.c	kernel: remove stop_machine() Kconfig dependency	2015-12-12 10:15:34 -08:00
sys.c	prctl: take mmap sem for writing to protect against others	2016-02-25 12:01:25 -08:00
sys_ni.c	mm: mlock: add new mlock system call	2015-11-05 19:34:48 -08:00
sysctl.c	timer/sysclt: Restrict timer migration sysctl values to 0 and 1	2017-10-05 09:41:47 +02:00
sysctl_binary.c	fs/coredump: prevent fsuid=0 dumps into user-controlled directories	2016-04-12 09:08:58 -07:00
task_work.c
taskstats.c
test_kprobes.c
torture.c	torture: Consolidate cond_resched_rcu_qs() into stutter_wait()	2015-10-06 11:25:01 -07:00
tracepoint.c	tracepoint: Give priority to probes of tracepoints	2015-10-25 21:33:54 -04:00
tsacct.c
uid16.c	kernel: make groups_sort calling a responsibility group_info allocators	2018-01-10 09:27:10 +01:00
up.c
user-return-notifier.c
user.c
user_namespace.c
utsname.c
utsname_sysctl.c
watchdog.c	kernel/watchdog: use nmi registers snapshot in hardlockup handler	2017-01-06 11:16:16 +01:00
workqueue.c	workqueue: Allow retrieval of current task's work struct	2018-03-18 11:17:48 +01:00
workqueue_internal.h	workqueue: Fix NULL pointer dereference	2017-11-15 17:13:11 +01:00