kernel_optimize_test/kernel
Huang Ying fb842b00c5 printk: use RCU to prevent potential lock contention in kmsg_dump
dump_list_lock is used to protect dump_list in kmsg_dumper implementation,
kmsg_dump() uses it to traverse dump_list too.  But if there is contention
on the lock, kmsg_dump() will fail, and the valuable kernel message may be
lost.

This patch solves this issue with RCU.  Because kmsg_dump() only read the
list, no lock is needed in kmsg_dump().  So that kmsg_dump() will never
fail because of lock contention.

Signed-off-by: Huang Ying <ying.huang@intel.com>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13 08:03:09 -08:00
..
debug
gcov
irq sched: Constify function scope static struct sched_param usage 2011-01-07 15:55:45 +01:00
power Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6 2011-01-10 08:14:53 -08:00
time Merge branch 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2011-01-07 17:02:58 -08:00
trace Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2011-01-11 11:02:13 -08:00
.gitignore
acct.c
async.c
audit_tree.c
audit_watch.c
audit.c
audit.h
auditfilter.c
auditsc.c
backtracetest.c
bounds.c
capability.c
cgroup_freezer.c
cgroup.c fs: dcache reduce branches in lookup path 2011-01-07 17:50:28 +11:00
compat.c
configs.c
cpu.c Merge branches 'x86-alternatives-for-linus', 'x86-fpu-for-linus', 'x86-hwmon-for-linus', 'x86-paravirt-for-linus', 'core-locking-for-linus' and 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2011-01-06 11:11:50 -08:00
cpuset.c
cred.c
delayacct.c
dma.c
elfcore.c
exec_domain.c
exit.c Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2011-01-11 11:02:13 -08:00
extable.c
fork.c Merge branch 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2011-01-07 17:02:58 -08:00
freezer.c
futex_compat.c
futex.c
groups.c
hrtimer.c Merge branch 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2011-01-07 17:02:58 -08:00
hung_task.c
hw_breakpoint.c
irq_work.c
itimer.c
jump_label.c
kallsyms.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kexec.c
kfifo.c
kmod.c
kprobes.c Merge branch 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2011-01-07 17:02:58 -08:00
ksysfs.c
kthread.c sched: Constify function scope static struct sched_param usage 2011-01-07 15:55:45 +01:00
latencytop.c
lockdep_internals.h
lockdep_proc.c
lockdep_states.h
lockdep.c
Makefile kernel: clean up USE_GENERIC_SMP_HELPERS 2011-01-13 08:03:08 -08:00
module.c
mutex-debug.c
mutex-debug.h
mutex.c
mutex.h
notifier.c
ns_cgroup.c
nsproxy.c
padata.c
panic.c
params.c
perf_event.c perf_events: Add perf_event_time() 2011-01-07 15:08:51 +01:00
pid_namespace.c
pid.c
pm_qos_params.c
posix-cpu-timers.c
posix-timers.c
printk.c printk: use RCU to prevent potential lock contention in kmsg_dump 2011-01-13 08:03:09 -08:00
profile.c
ptrace.c
range.c
rcupdate.c
rcutiny_plugin.h
rcutiny.c
rcutorture.c
rcutree_plugin.h
rcutree_trace.c
rcutree.c Merge branch 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2011-01-07 17:02:58 -08:00
rcutree.h
relay.c
res_counter.c
resource.c
rtmutex_common.h
rtmutex-debug.c
rtmutex-debug.h
rtmutex-tester.c
rtmutex.c
rtmutex.h
rwsem.c
sched_autogroup.c sched: Mark autogroup_init() __init 2011-01-07 15:54:36 +01:00
sched_autogroup.h
sched_clock.c
sched_cpupri.c
sched_cpupri.h
sched_debug.c
sched_fair.c
sched_features.h
sched_idletask.c
sched_rt.c
sched_stats.h
sched_stoptask.c
sched.c sched: Fix strncmp operation 2011-01-07 15:55:10 +01:00
seccomp.c
semaphore.c
signal.c
smp.c kernel: clean up USE_GENERIC_SMP_HELPERS 2011-01-13 08:03:08 -08:00
softirq.c kernel: clean up USE_GENERIC_SMP_HELPERS 2011-01-13 08:03:08 -08:00
spinlock.c
srcu.c
stacktrace.c
stop_machine.c
sys_ni.c
sys.c kmsg_dump: add kmsg_dump() calls to the reboot, halt, poweroff and emergency_restart paths 2011-01-13 08:03:07 -08:00
sysctl_binary.c
sysctl_check.c
sysctl.c kptr_restrict for hiding kernel pointers from unprivileged users 2011-01-13 08:03:08 -08:00
taskstats.c Merge branch 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2011-01-07 17:02:58 -08:00
test_kprobes.c
time.c
timeconst.pl
timer.c Merge branch 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2011-01-06 10:42:43 -08:00
tracepoint.c
tsacct.c
uid16.c
up.c
user_namespace.c
user-return-notifier.c
user.c
utsname_sysctl.c
utsname.c
wait.c
watchdog.c Merge branch 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2011-01-07 17:02:58 -08:00
workqueue_sched.h
workqueue.c