Paul E. McKenney 15651201fa rcu: Mark task as .need_qs less aggressively ...

If any scheduling-clock interrupt interrupts an RCU-preempt read-side
critical section, the interrupted task's ->rcu_read_unlock_special.b.need_qs
field is set.  This causes the outermost rcu_read_unlock() to incur the
extra overhead of calling into rcu_read_unlock_special().  This commit
reduces that overhead by setting ->rcu_read_unlock_special.b.need_qs only
if the grace period has been in effect for more than one second.

Why one second?  Because this is comfortably smaller than the minimum
RCU CPU stall-warning timeout of three seconds, but long enough that the
.need_qs marking should happen quite rarely.  And if your RCU read-side
critical section has run on-CPU for a full second, it is not unreasonable
to invest some CPU time in ending the grace period quickly.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

2018-07-12 15:39:15 -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

Merge tag 'printk-for-4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk

2018-06-06 16:04:55 -07:00

rcu

rcu: Mark task as .need_qs less aggressively

2018-07-12 15:39:15 -07:00

sched

sched/core / kcov: avoid kcov_area during task switch

2018-06-15 07:55:24 +09:00

time

Merge tag 'pm-4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

2018-06-05 09:38:39 -07:00

trace

docs: Fix some broken references

2018-06-15 18:10:01 -03:00

.gitignore

…

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_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

Merge tag 'fsnotify_for_v4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs

2018-06-17 05:06:18 +09:00

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

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_pm.c

PM / CPU: replace raw_notifier with atomic_notifier

2017-07-31 13:09:49 +02:00

cpu.c

cpu/hotplug: Fix unused function warning

2018-03-15 20:34:40 +01:00

crash_core.c

mm: split page_type out from _mapcount

2018-06-07 17:34:37 -07:00

crash_dump.c

…

cred.c

doc: ReSTify credentials.txt

2017-05-18 10:30:19 -06:00

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_compat.c

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02 11:10:55 +01:00

futex.c

pids: introduce find_get_task_by_vpid() helper

2018-02-06 18:32:46 -08:00

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

Kconfig.freezer

…

Kconfig.hz

…

Kconfig.locks

…

Kconfig.preempt

…

kcov.c

sched/core / kcov: avoid kcov_area during task switch

2018-06-15 07:55:24 +09:00

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

kexec.c

kexec: call do_kexec_load() in compat syscall directly

2018-04-02 20:15:01 +02:00

kmod.c

kmod: move #ifdef CONFIG_MODULES wrapper to Makefile

2017-09-08 18:26:51 -07:00

kprobes.c

kprobes: Fix random address output of blacklist file

2018-04-25 10:27:56 -04:00

ksysfs.c

kexec: move vmcoreinfo out of the kernel's .bss section

2017-07-12 16:25:59 -07:00

kthread.c

kthread: Allow kthread_park() on a parked kthread

2018-05-25 08:03:51 +02:00

latencytop.c

…

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

memremap.c

mm: introduce MEMORY_DEVICE_FS_DAX and CONFIG_DEV_PAGEMAP_OPS

2018-05-22 06:59:39 -07:00

module_signing.c

…

module-internal.h

…

module.c

Merge tag 'modules-for-v4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux

2018-06-16 07:36:39 +09:00

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_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

pid.c

xarray: add the xa_lock to the radix_tree_root

2018-04-11 10:28:39 -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

Merge tag 'libnvdimm-for-4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

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

Merge tag 'audit-pr-20180605' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit

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

Merge tag 'v4.17-rc5' into locking/core, to pick up fixes

2018-05-15 08:10:50 +02:00

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

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

sysctl_binary.c

staging: irda: remove remaining remants of irda code removal

2018-04-16 11:26:49 +02:00

sysctl.c

treewide: kzalloc() -> kcalloc()

2018-06-12 16:19:22 -07:00

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

smp: Avoid using two cache lines for struct call_single_data

2017-08-29 15:14:38 +02:00

user_namespace.c

treewide: kmalloc() -> kmalloc_array()

2018-06-12 16:19:22 -07:00

user-return-notifier.c

…

user.c

efivarfs: Limit the rate for non-root to read files

2018-02-22 10:21:02 -08:00

utsname_sysctl.c

…

utsname.c

uts: create "struct uts_namespace" from kmem_cache

2018-04-11 10:28:35 -07:00

watchdog_hld.c

Merge branch 'linus' into core/urgent, to pick up dependent commits

2017-11-04 08:53:04 +01:00

watchdog.c

Merge branch 'linus' into sched/core, to pick up fixes

2017-11-08 10:17:15 +01:00

workqueue_internal.h

workqueue: Set worker->desc to workqueue name by default

2018-05-18 08:47:13 -07:00

workqueue.c

treewide: kzalloc() -> kcalloc()

2018-06-12 16:19:22 -07:00