Paul E. McKenney ec2c29765a rcu: Fix grace-period hangs from mid-init task resume ... Without special fail-safe quiescent-state-propagation checks, grace-period hangs can result from the following scenario: 1. A task running on a given CPU is preempted in its RCU read-side critical section. 2. That CPU goes offline, and there are now no online CPUs corresponding to that CPU's leaf rcu_node structure. 3. The rcu_gp_init() function does the first phase of grace-period initialization, and sets the aforementioned leaf rcu_node structure's ->qsmaskinit field to all zeroes. Because there is a blocked task, it does not propagate the zeroing of either ->qsmaskinit or ->qsmaskinitnext up the rcu_node tree. 4. The task resumes on some other CPU and exits its critical section. There is no grace period in progress, so the resulting quiescent state is not reported up the tree. 5. The rcu_gp_init() function does the second phase of grace-period initialization, which results in the leaf rcu_node structure being initialized to expect no further quiescent states, but with that structure's parent expecting a quiescent-state report. The parent will never receive a quiescent state from this leaf rcu_node structure, so the grace period will hang, resulting in RCU CPU stall warnings. It would be good to get rid of the special fail-safe quiescent-state propagation checks. This commit therefore checks the leaf rcu_node structure's ->wait_blkd_tasks field during grace-period initialization. If this flag is set, the rcu_report_qs_rnp() is invoked to immediately report the possible quiescent state. While in the neighborhood, this commit also report quiescent states for any CPUs that went offline between the two phases of grace-period initialization, thus reducing grace-period delays and hopefully eventually allowing removal of offline-CPU checks from the force-quiescent-state code path. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>		2018-07-12 15:39:04 -07:00
..
bpf	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net	2018-06-16 07:39:34 +09:00
cgroup	docs: Fix some broken references	2018-06-15 18:10:01 -03:00
configs	kconfig: tinyconfig: remove stale stack protector fixups	2018-06-15 07:15:28 +09:00
debug	treewide: kzalloc() -> kcalloc()	2018-06-12 16:19:22 -07:00
events	treewide: kzalloc_node() -> kcalloc_node()	2018-06-12 16:19:22 -07:00
gcov	gcov: remove CONFIG_GCOV_FORMAT_AUTODETECT	2018-06-08 18:56:02 +09:00
irq	Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2018-06-10 09:44:53 -07:00
livepatch	livepatch: Allow to call a custom callback when freeing shadow variables	2018-04-17 13:42:48 +02:00
locking	torture: Keep old-school dmesg format	2018-06-25 11:30:10 -07:00
power	fix a series of Documentation/ broken file name references	2018-06-15 18:10:01 -03:00
printk	Printk changes for 4.18	2018-06-06 16:04:55 -07:00
rcu	rcu: Fix grace-period hangs from mid-init task resume	2018-07-12 15:39:04 -07:00
sched	sched/core / kcov: avoid kcov_area during task switch	2018-06-15 07:55:24 +09:00
time	Power management updates for 4.18-rc1	2018-06-05 09:38:39 -07:00
trace	docs: Fix some broken references	2018-06-15 18:10:01 -03:00
.gitignore	…
Kconfig.freezer	…
Kconfig.hz	…
Kconfig.locks	…
Kconfig.preempt	…
Makefile	Merge branch 'core-rseq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2018-06-10 10:17:09 -07:00
acct.c	kernel/acct.c: fix the acct->needcheck check in check_free_space()	2018-01-04 16:45:09 -08:00
async.c	kernel/async.c: revert "async: simplify lowest_in_progress()"	2018-02-06 18:32:44 -08:00
audit.c	audit: use inline function to get audit context	2018-05-14 17:24:18 -04:00
audit.h	audit: track the owner of the command mutex ourselves	2018-02-23 11:22:22 -05:00
audit_fsnotify.c	fsnotify: add fsnotify_add_inode_mark() wrappers	2018-05-18 14:58:22 +02:00
audit_tree.c	fsnotify: add fsnotify_add_inode_mark() wrappers	2018-05-18 14:58:22 +02:00
audit_watch.c	\n	2018-06-17 05:06:18 +09:00
auditfilter.c	audit: use existing session info function	2018-05-18 15:47:54 -04:00
auditsc.c	audit: Fix wrong task in comparison of session ID	2018-05-21 14:27:43 -04:00
backtracetest.c	…
bounds.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
capability.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
compat.c	Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2018-06-04 20:27:54 -07:00
configs.c	…
context_tracking.c	…
cpu.c	cpu/hotplug: Fix unused function warning	2018-03-15 20:34:40 +01:00
cpu_pm.c	…
crash_core.c	mm: split page_type out from _mapcount	2018-06-07 17:34:37 -07:00
crash_dump.c	…
cred.c	…
delayacct.c	delayacct: Use raw_spinlocks	2018-04-27 14:34:51 +02:00
dma.c	proc: introduce proc_create_single{,_data}	2018-05-16 07:23:35 +02:00
elfcore.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
exec_domain.c	proc: introduce proc_create_single{,_data}	2018-05-16 07:23:35 +02:00
exit.c	kernel: use kernel_wait4() instead of sys_wait4()	2018-04-02 20:14:51 +02:00
extable.c	extable: Make init_kernel_text() global	2018-02-21 16:54:06 +01:00
fail_function.c	treewide: kmalloc() -> kmalloc_array()	2018-06-12 16:19:22 -07:00
fork.c	mm: check for SIGKILL inside dup_mmap() loop	2018-06-15 07:55:24 +09:00
freezer.c	…
futex.c	pids: introduce find_get_task_by_vpid() helper	2018-02-06 18:32:46 -08:00
futex_compat.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
groups.c	kernel: make groups_sort calling a responsibility group_info allocators	2017-12-14 16:00:49 -08:00
hung_task.c	kernel/hung_task.c: show all hung tasks before panic	2018-06-07 17:34:39 -07:00
iomem.c	memremap: split devm_memremap_pages() and memremap() infrastructure	2018-05-15 23:08:33 -07:00
irq_work.c	irq/work: Improve the flag definitions	2018-01-08 19:43:15 +01:00
jump_label.c	jump_label: Disable jump labels in __exit code	2018-03-20 08:57:17 +01:00
kallsyms.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk	2018-02-01 13:36:15 -08:00
kcmp.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
kcov.c	sched/core / kcov: avoid kcov_area during task switch	2018-06-15 07:55:24 +09:00
kexec.c	kexec: call do_kexec_load() in compat syscall directly	2018-04-02 20:15:01 +02:00
kexec_core.c	kexec: yield to scheduler when loading kimage segments	2018-06-15 07:55:24 +09:00
kexec_file.c	treewide: Use array_size() in vzalloc()	2018-06-12 16:19:22 -07:00
kexec_internal.h	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
kmod.c	…
kprobes.c	kprobes: Fix random address output of blacklist file	2018-04-25 10:27:56 -04:00
ksysfs.c	…
kthread.c	kthread: Allow kthread_park() on a parked kthread	2018-05-25 08:03:51 +02:00
latencytop.c	…
memremap.c	mm: introduce MEMORY_DEVICE_FS_DAX and CONFIG_DEV_PAGEMAP_OPS	2018-05-22 06:59:39 -07:00
module-internal.h	…
module.c	Modules updates for v4.18	2018-06-16 07:36:39 +09:00
module_signing.c	…
notifier.c	…
nsproxy.c	…
padata.c	padata: add SPDX identifier	2018-01-05 18:43:00 +11:00
panic.c	Kbuild: rename CC_STACKPROTECTOR[_STRONG] config variables	2018-06-14 12:21:18 +09:00
params.c	kernel/params.c: downgrade warning for unsafe parameters	2018-04-11 10:28:37 -07:00
pid.c	xarray: add the xa_lock to the radix_tree_root	2018-04-11 10:28:39 -07:00
pid_namespace.c	Merge branch 'userns-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace	2018-04-03 19:15:32 -07:00
profile.c	…
ptrace.c	pids: introduce find_get_task_by_vpid() helper	2018-02-06 18:32:46 -08:00
range.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
reboot.c	kernel/reboot.c: add devm_register_reboot_notifier()	2017-11-17 16:10:04 -08:00
relay.c	kernel/relay.c: change return type to vm_fault_t	2018-06-15 07:55:24 +09:00
resource.c	libnvdimm for 4.18	2018-06-08 17:21:52 -07:00
rseq.c	rseq: Introduce restartable sequences system call	2018-06-06 11:58:31 +02:00
seccomp.c	audit/stable-4.18 PR 20180605	2018-06-06 16:34:00 -07:00
signal.c	signal: Remove no longer required irqsave/restore	2018-06-10 06:14:01 +02:00
smp.c	smp/core: Use lockdep to assert IRQs are disabled/enabled	2017-11-08 11:13:50 +01:00
smpboot.c	watchdog/core, powerpc: Lock cpus across reconfiguration	2017-10-04 10:53:54 +02:00
smpboot.h	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
softirq.c	Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2018-06-04 19:59:22 -07:00
stacktrace.c	…
stop_machine.c	Linux 4.17-rc5	2018-05-15 08:10:50 +02:00
sys.c	mm: introduce arg_lock to protect arg_start|end and env_start|end in mm_struct	2018-06-07 17:34:34 -07:00
sys_ni.c	Merge branch 'core-rseq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2018-06-10 10:17:09 -07:00
sysctl.c	treewide: kzalloc() -> kcalloc()	2018-06-12 16:19:22 -07:00
sysctl_binary.c	staging: irda: remove remaining remants of irda code removal	2018-04-16 11:26:49 +02:00
task_work.c	locking/barriers: Convert users of lockless_dereference() to READ_ONCE()	2017-12-17 13:57:15 +01:00
taskstats.c	pids: introduce find_get_task_by_vpid() helper	2018-02-06 18:32:46 -08:00
test_kprobes.c	kprobes: Disable the jprobes test code	2017-10-20 11:02:54 +02:00
torture.c	torture: Keep old-school dmesg format	2018-06-25 11:30:10 -07:00
tracepoint.c	tracepoints: Fix the descriptions of tracepoint_probe_register{_prio}	2018-05-28 12:49:51 -04:00
tsacct.c	…
ucount.c	headers: untangle kmemleak.h from mm.h	2018-04-05 21:36:27 -07:00
uid16.c	fs: add do_fchownat(), ksys_fchown() helpers and ksys_{,l}chown() wrappers	2018-04-02 20:15:59 +02:00
uid16.h	kernel: provide ksys_*() wrappers for syscalls called by kernel/uid16.c	2018-04-02 20:15:30 +02:00
umh.c	umh: fix race condition	2018-06-07 16:56:28 -04:00
up.c	…
user-return-notifier.c	…
user.c	efivarfs: Limit the rate for non-root to read files	2018-02-22 10:21:02 -08:00
user_namespace.c	treewide: kmalloc() -> kmalloc_array()	2018-06-12 16:19:22 -07:00
utsname.c	uts: create "struct uts_namespace" from kmem_cache	2018-04-11 10:28:35 -07:00
utsname_sysctl.c	…
watchdog.c	Merge branch 'linus' into sched/core, to pick up fixes	2017-11-08 10:17:15 +01:00
watchdog_hld.c	Merge branch 'linus' into core/urgent, to pick up dependent commits	2017-11-04 08:53:04 +01:00
workqueue.c	treewide: kzalloc() -> kcalloc()	2018-06-12 16:19:22 -07:00
workqueue_internal.h	workqueue: Set worker->desc to workqueue name by default	2018-05-18 08:47:13 -07:00