linux/kernel
Paul E. McKenney 1d082fd061 rcu: Remove local_irq_disable() in rcu_preempt_note_context_switch()
The rcu_preempt_note_context_switch() function is on a scheduling fast
path, so it would be good to avoid disabling irqs.  The reason that irqs
are disabled is to synchronize process-level and irq-handler access to
the task_struct ->rcu_read_unlock_special bitmask.  This commit therefore
makes ->rcu_read_unlock_special instead be a union of bools with a short
allowing single-access checks in RCU's __rcu_read_unlock().  This results
in the process-level and irq-handler accesses being simple loads and
stores, so that irqs need no longer be disabled.  This commit therefore
removes the irq disabling from rcu_preempt_note_context_switch().

Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2014-09-07 16:27:34 -07:00
..
bpf net: filter: split 'struct sk_filter' into socket and bpf parts 2014-08-02 15:03:58 -07:00
debug kdb: Use ktime_get_ts() 2014-06-12 16:18:45 +02:00
events Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-08-24 16:16:55 -07:00
gcov kernel/gcov/fs.c: remove unnecessary null test before debugfs_remove 2014-08-08 15:57:24 -07:00
irq Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-08-05 17:38:45 -07:00
locking arch, locking: Ciao arch_mutex_cpu_relax() 2014-07-17 12:32:47 +02:00
power Merge branches 'pm-sleep', 'pm-cpufreq' and 'pm-cpuidle' 2014-08-11 23:19:48 +02:00
printk printk: Add function to return log buffer address and size 2014-08-13 15:13:44 +10:00
rcu rcu: Remove local_irq_disable() in rcu_preempt_note_context_switch() 2014-09-07 16:27:34 -07:00
sched Merge branches 'pm-sleep', 'pm-cpufreq' and 'pm-cpuidle' 2014-08-11 23:19:48 +02:00
time timekeeping: Another fix to the VSYSCALL_OLD update_vsyscall 2014-08-14 11:04:11 -06:00
trace ftrace: Use current addr when converting to nop in __ftrace_replace_code() 2014-08-22 21:04:35 -04:00
.gitignore
acct.c kernel/acct.c: fix coding style warnings and errors 2014-08-08 15:57:27 -07:00
async.c
audit_tree.c
audit_watch.c
audit.c CAPABILITIES: remove undefined caps from all processes 2014-07-24 21:53:47 +10:00
audit.h
auditfilter.c kernel/auditfilter.c: replace count*size kmalloc by kcalloc 2014-08-06 18:01:12 -07:00
auditsc.c auditsc: audit_krule mask accesses need bounds checking 2014-06-10 08:44:40 -07:00
backtracetest.c kernel/backtracetest.c: replace no level printk by pr_info() 2014-06-04 16:54:14 -07:00
bounds.c page-cgroup: get rid of NR_PCG_FLAGS 2014-08-08 15:57:18 -07:00
capability.c CAPABILITIES: remove undefined caps from all processes 2014-07-24 21:53:47 +10:00
cgroup_freezer.c cgroup: rename cgroup_subsys->base_cftypes to ->legacy_cftypes 2014-07-15 11:05:09 -04:00
cgroup.c Merge branch 'for-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2014-08-04 10:11:28 -07:00
compat.c kernel/compat.c: use sizeof() instead of sizeof 2014-06-04 16:54:19 -07:00
configs.c
context_tracking.c x86/kprobes: Fix build errors and blacklist context_track_user 2014-06-14 09:07:44 +02:00
cpu_pm.c
cpu.c sched: Rework check_for_tasks() 2014-07-05 11:17:45 +02:00
cpuset.c Merge branch 'for-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2014-08-04 10:11:28 -07:00
crash_dump.c
cred.c
delayacct.c delayacct: Remove braindamaged type conversions 2014-07-23 10:18:06 -07:00
dma.c
elfcore.c
exec_domain.c kernel/exec_domain.c: code clean-up 2014-06-04 16:54:15 -07:00
exit.c rcu: Make TASKS_RCU handle tasks that are almost done exiting 2014-09-07 16:27:22 -07:00
extable.c
fork.c seccomp: Replace BUG(!spin_is_locked()) with assert_spin_lock 2014-08-11 13:29:12 -07:00
freezer.c
futex_compat.c
futex.c futex: Simplify futex_lock_pi_atomic() and make it more robust 2014-06-21 22:26:24 +02:00
groups.c
hung_task.c kernel/hung_task.c: convert simple_strtoul to kstrtouint 2014-06-04 16:54:15 -07:00
irq_work.c irq_work: Remove BUG_ON in irq_work_run() 2014-07-05 11:17:26 +02:00
jump_label.c
kallsyms.c kernel/kallsyms.c: fix %pB when there's no symbol at the address 2014-08-08 15:57:18 -07:00
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks locking/rwsem: Add CONFIG_RWSEM_SPIN_ON_OWNER 2014-07-16 14:57:13 +02:00
Kconfig.preempt
kexec.c kexec: verify the signature of signed PE bzImage 2014-08-08 15:57:33 -07:00
kmod.c signals: change wait_for_helper() to use kernel_sigaction() 2014-06-06 16:08:12 -07:00
kprobes.c kprobes: Skip kretprobe hit in NMI context to avoid deadlock 2014-08-08 10:38:04 +02:00
ksysfs.c
kthread.c kthread_work: wake up worker only when the worker is idle 2014-07-28 14:07:52 -04:00
latencytop.c kernel/latencytop.c: convert seq_printf to seq_puts 2014-06-04 16:54:15 -07:00
Makefile bin2c: move bin2c in scripts/basic 2014-08-08 15:57:32 -07:00
module_signing.c
module-internal.h
module.c module: Clean up ro/nx after early module load failures 2014-08-16 04:47:00 +09:30
notifier.c
nsproxy.c namespaces: Use task_lock and not rcu to protect nsproxy 2014-07-29 18:08:50 -07:00
padata.c
panic.c panic: add TAINT_SOFTLOCKUP 2014-08-08 15:57:24 -07:00
params.c Add module param type 'ullong' 2014-07-17 22:07:37 +02:00
pid_namespace.c
pid.c
profile.c kernel/profile.c: use static const char instead of static char 2014-06-06 16:08:13 -07:00
ptrace.c sched: Remove proliferation of wait_on_bit() action functions 2014-07-16 15:10:39 +02:00
range.c
reboot.c kernel/reboot.c: convert simple_strtoul to kstrtoint 2014-06-04 16:54:15 -07:00
relay.c
res_counter.c kernel/res_counter.c: replace simple_strtoull by kstrtoull 2014-06-04 16:54:15 -07:00
resource.c resource: provide new functions to walk through resources 2014-08-08 15:57:32 -07:00
seccomp.c seccomp: Replace BUG(!spin_is_locked()) with assert_spin_lock 2014-08-11 13:29:12 -07:00
signal.c Merge branch 'signal-cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc 2014-08-09 09:58:12 -07:00
smp.c kernel/smp.c:on_each_cpu_cond(): fix warning in fallback path 2014-08-06 18:01:22 -07:00
smpboot.c
smpboot.h
softirq.c Merge branch 'rcu/next' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu 2014-05-22 11:36:10 +02:00
stacktrace.c
stop_machine.c kernel/stop_machine.c: kernel-doc warning fix 2014-06-04 16:54:15 -07:00
sys_ni.c kexec: new syscall kexec_file_load() declaration 2014-08-08 15:57:32 -07:00
sys.c sched: move no_new_privs into new atomic flags 2014-07-18 12:13:38 -07:00
sysctl_binary.c ipv6: Allow accepting RA from local IP addresses. 2014-07-01 12:16:24 -07:00
sysctl.c mm, hugetlb: remove hugetlb_zero and hugetlb_infinity 2014-08-06 18:01:19 -07:00
system_certificates.S
system_keyring.c KEYS: validate certificate trust only with builtin keys 2014-07-17 09:35:17 -04:00
task_work.c
taskstats.c
test_kprobes.c kernel/test_kprobes.c: use current logging functions 2014-08-08 15:57:18 -07:00
torture.c torture: Avoid format string leak to thead name 2014-07-07 10:12:56 -07:00
tracepoint.c tracing: syscall_regfunc() should not skip kernel threads 2014-06-21 00:15:26 -04:00
tsacct.c sched: Make task->start_time nanoseconds based 2014-07-23 10:18:05 -07:00
uid16.c
up.c
user_namespace.c proc: constify seq_operations 2014-08-08 15:57:22 -07:00
user-return-notifier.c
user.c kernel/user.c: drop unused field 'files' from user_struct 2014-06-04 16:54:16 -07:00
utsname_sysctl.c sysctl: convert use of typedef ctl_table to struct ctl_table 2014-06-06 16:08:16 -07:00
utsname.c namespaces: Use task_lock and not rcu to protect nsproxy 2014-07-29 18:08:50 -07:00
watchdog.c panic: add TAINT_SOFTLOCKUP 2014-08-08 15:57:24 -07:00
workqueue_internal.h workqueue: rename manager_mutex to attach_mutex 2014-05-20 10:59:32 -04:00
workqueue.c Merge branch 'for-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2014-08-04 10:09:27 -07:00