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
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
2018-06-16 07:39:34 +09:00
docs: Fix some broken references
2018-06-15 18:10:01 -03:00
kconfig: tinyconfig: remove stale stack protector fixups
2018-06-15 07:15:28 +09:00
treewide: kzalloc() -> kcalloc()
2018-06-12 16:19:22 -07:00
treewide: kzalloc_node() -> kcalloc_node()
2018-06-12 16:19:22 -07:00
gcov: remove CONFIG_GCOV_FORMAT_AUTODETECT
2018-06-08 18:56:02 +09:00
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: Allow to call a custom callback when freeing shadow variables
2018-04-17 13:42:48 +02:00
torture: Keep old-school dmesg format
2018-06-25 11:30:10 -07:00
fix a series of Documentation/ broken file name references
2018-06-15 18:10:01 -03:00
Printk changes for 4.18
2018-06-06 16:04:55 -07:00
rcu: Fix grace-period hangs from mid-init task resume
2018-07-12 15:39:04 -07:00
sched/core / kcov: avoid kcov_area during task switch
2018-06-15 07:55:24 +09:00
Power management updates for 4.18-rc1
2018-06-05 09:38:39 -07:00
docs: Fix some broken references
2018-06-15 18:10:01 -03:00
audit: use inline function to get audit context
2018-05-14 17:24:18 -04:00
audit: track the owner of the command mutex ourselves
2018-02-23 11:22:22 -05:00
fsnotify: add fsnotify_add_inode_mark() wrappers
2018-05-18 14:58:22 +02:00
fsnotify: add fsnotify_add_inode_mark() wrappers
2018-05-18 14:58:22 +02:00
\n
2018-06-17 05:06:18 +09:00
audit: use existing session info function
2018-05-18 15:47:54 -04:00
audit: Fix wrong task in comparison of session ID
2018-05-21 14:27:43 -04:00
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
cpu/hotplug: Fix unused function warning
2018-03-15 20:34:40 +01:00
mm: split page_type out from _mapcount
2018-06-07 17:34:37 -07:00
delayacct: Use raw_spinlocks
2018-04-27 14:34:51 +02:00
proc: introduce proc_create_single{,_data}
2018-05-16 07:23:35 +02:00
proc: introduce proc_create_single{,_data}
2018-05-16 07:23:35 +02:00
kernel: use kernel_wait4() instead of sys_wait4()
2018-04-02 20:14:51 +02:00
treewide: kmalloc() -> kmalloc_array()
2018-06-12 16:19:22 -07:00
mm: check for SIGKILL inside dup_mmap() loop
2018-06-15 07:55:24 +09:00
kernel/hung_task.c: show all hung tasks before panic
2018-06-07 17:34:39 -07:00
memremap: split devm_memremap_pages() and memremap() infrastructure
2018-05-15 23:08:33 -07:00
jump_label: Disable jump labels in __exit code
2018-03-20 08:57:17 +01:00
sched/core / kcov: avoid kcov_area during task switch
2018-06-15 07:55:24 +09:00
kexec: call do_kexec_load() in compat syscall directly
2018-04-02 20:15:01 +02:00
kexec: yield to scheduler when loading kimage segments
2018-06-15 07:55:24 +09:00
treewide: Use array_size() in vzalloc()
2018-06-12 16:19:22 -07:00
kprobes: Fix random address output of blacklist file
2018-04-25 10:27:56 -04:00
kthread: Allow kthread_park() on a parked kthread
2018-05-25 08:03:51 +02:00
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
mm: introduce MEMORY_DEVICE_FS_DAX and CONFIG_DEV_PAGEMAP_OPS
2018-05-22 06:59:39 -07:00
Modules updates for v4.18
2018-06-16 07:36:39 +09:00
Kbuild: rename CC_STACKPROTECTOR[_STRONG] config variables
2018-06-14 12:21:18 +09:00
kernel/params.c: downgrade warning for unsafe parameters
2018-04-11 10:28:37 -07:00
xarray: add the xa_lock to the radix_tree_root
2018-04-11 10:28:39 -07:00
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
kernel/relay.c: change return type to vm_fault_t
2018-06-15 07:55:24 +09:00
libnvdimm for 4.18
2018-06-08 17:21:52 -07:00
rseq: Introduce restartable sequences system call
2018-06-06 11:58:31 +02:00
audit/stable-4.18 PR 20180605
2018-06-06 16:34:00 -07:00
signal: Remove no longer required irqsave/restore
2018-06-10 06:14:01 +02:00
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
Linux 4.17-rc5
2018-05-15 08:10:50 +02:00
mm: introduce arg_lock to protect arg_start|end and env_start|end in mm_struct
2018-06-07 17:34:34 -07:00
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
treewide: kzalloc() -> kcalloc()
2018-06-12 16:19:22 -07:00
staging: irda: remove remaining remants of irda code removal
2018-04-16 11:26:49 +02:00
torture: Keep old-school dmesg format
2018-06-25 11:30:10 -07:00
tracepoints: Fix the descriptions of tracepoint_probe_register{_prio}
2018-05-28 12:49:51 -04:00
headers: untangle kmemleak.h from mm.h
2018-04-05 21:36:27 -07:00
fs: add do_fchownat(), ksys_fchown() helpers and ksys_{,l}chown() wrappers
2018-04-02 20:15:59 +02:00
kernel: provide ksys_*() wrappers for syscalls called by kernel/uid16.c
2018-04-02 20:15:30 +02:00
umh: fix race condition
2018-06-07 16:56:28 -04:00
efivarfs: Limit the rate for non-root to read files
2018-02-22 10:21:02 -08:00
treewide: kmalloc() -> kmalloc_array()
2018-06-12 16:19:22 -07:00
uts: create "struct uts_namespace" from kmem_cache
2018-04-11 10:28:35 -07:00
treewide: kzalloc() -> kcalloc()
2018-06-12 16:19:22 -07:00
workqueue: Set worker->desc to workqueue name by default
2018-05-18 08:47:13 -07:00
ec2c29765a