Mathieu Desnoyers 6496968e6c markers: use synchronize_sched() ... Markers do not mix well with CONFIG_PREEMPT_RCU because it uses preempt_disable/enable() and not rcu_read_lock/unlock for minimal intrusiveness. We would need call_sched and sched_barrier primitives. Currently, the modification (connection and disconnection) of probes from markers requires changes to the data structure done in RCU-style : a new data structure is created, the pointer is changed atomically, a quiescent state is reached and then the old data structure is freed. The quiescent state is reached once all the currently running preempt_disable regions are done running. We use the call_rcu mechanism to execute kfree() after such quiescent state has been reached. However, the new CONFIG_PREEMPT_RCU version of call_rcu and rcu_barrier does not guarantee that all preempt_disable code regions have finished, hence the race. The "proper" way to do this is to use rcu_read_lock/unlock, but we don't want to use it to minimize intrusiveness on the traced system. (we do not want the marker code to call into much of the OS code, because it would quickly restrict what can and cannot be instrumented, such as the scheduler). The temporary fix, until we get call_rcu_sched and rcu_barrier_sched in mainline, is to use synchronize_sched before each call_rcu calls, so we wait for the quiescent state in the system call code path. It will slow down batch marker enable/disable, but will make sure the race is gone. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2008-04-02 15:28:19 -07:00
..
irq	genirq: do not leave interupts enabled on free_irq	2008-02-19 10:43:58 +01:00
power	Merge branches 'release' and 'doc' into release	2008-03-13 01:59:53 -04:00
time	clocksource: revert: use init_timer_deferrable for clocksource_watchdog	2008-03-25 20:13:25 +01:00
.gitignore	Update kernel/.gitignore with new auto-generated files	2008-02-09 23:27:01 -08:00
acct.c	bsd_acct: using task_struct->tgid is not right in pid-namespaces	2008-03-24 19:22:20 -07:00
audit.c	audit: silence two kerneldoc warnings in kernel/audit.c	2008-03-28 14:45:21 -07:00
audit.h	[PATCH] audit: watching subtrees	2007-10-21 02:37:45 -04:00
audit_tree.c	Introduce path_put()	2008-02-14 21:13:33 -08:00
auditfilter.c	Introduce path_put()	2008-02-14 21:13:33 -08:00
auditsc.c	[PATCH] Audit: Fix the format type for size_t variables	2008-03-01 07:16:06 -05:00
backtracetest.c	x86: add a simple backtrace test module	2008-01-30 13:33:08 +01:00
capability.c	Add 64-bit capability support to the kernel	2008-02-05 09:44:20 -08:00
cgroup.c	NULL noise: fs/*, mm/*, kernel/*	2008-03-30 14:18:41 -07:00
cgroup_debug.c	Task Control Groups: simple task cgroup debug info subsystem	2007-10-19 11:53:36 -07:00
compat.c	hrtimer: don't modify restart_block->fn in restart functions	2008-02-10 10:48:03 +01:00
configs.c	use simple_read_from_buffer in kernel/	2007-05-09 12:30:49 -07:00
cpu.c	cpu: fix section mismatch warnings for enable_nonboot_cpus	2008-02-08 09:22:41 -08:00
cpuset.c	cpusets: fix obsolete comment	2008-03-05 17:53:33 -08:00
delayacct.c	Add scaled time to taskstats based process accounting	2007-10-18 14:37:28 -07:00
dma.c	whitespace fixes: DMA channel allocator	2007-10-18 14:37:24 -07:00
exec_domain.c	whitespace fixes: execution domains	2007-10-18 14:37:26 -07:00
exit.c	Fix waitid si_code regression	2008-03-08 11:54:00 -08:00
extable.c	module: Don't report discarded init pages as kernel text.	2008-01-29 17:13:18 +11:00
fork.c	memcgroup: fix spurious EBUSY on memory cgroup removal	2008-03-28 14:45:21 -07:00
futex.c	NULL noise: fs/*, mm/*, kernel/*	2008-03-30 14:18:41 -07:00
futex_compat.c	futex_compat __user annotation	2008-03-30 14:18:41 -07:00
hrtimer.c	hrtimer: catch expired CLOCK_REALTIME timers early	2008-02-14 22:08:30 +01:00
itimer.c	ITIMER_REAL: convert to use struct pid	2008-02-08 09:22:29 -08:00
kallsyms.c	remove support for un-needed _extratext section	2008-02-06 10:41:01 -08:00
Kconfig.hz	sched: high-res preemption tick	2008-01-25 21:08:29 +01:00
Kconfig.preempt	rcu: move PREEMPT_RCU config option back under PREEMPT	2008-03-10 18:01:20 -07:00
kexec.c	vmcoreinfo: add "VMCOREINFO_" to all the call for vmcoreinfo_append_str()	2008-02-07 08:42:25 -08:00
kfifo.c	is_power_of_2: kernel/kfifo.c	2007-07-16 09:05:50 -07:00
kmod.c	Dont touch fs_struct in usermodehelper	2008-02-14 21:13:32 -08:00
kprobes.c	kprobes: fix a null pointer bug in register_kretprobe()	2008-03-04 16:35:19 -08:00
ksysfs.c	Kobject: convert remaining kobject_unregister() to kobject_put()	2008-01-24 20:40:40 -08:00
kthread.c	sched: fix, always create kernel threads with normal priority	2008-01-25 21:08:33 +01:00
latencytop.c	sched: latencytop support	2008-01-25 21:08:34 +01:00
lockdep.c	Subject: lockdep: include all lock classes in all_lock_classes	2008-02-25 23:03:02 +01:00
lockdep_internals.h
lockdep_proc.c	lockdep: Avoid /proc/lockdep & lock_stat infinite output	2007-10-11 22:11:11 +02:00
Makefile	avoid overflows in kernel/time.c	2008-02-08 09:22:39 -08:00
marker.c	markers: use synchronize_sched()	2008-04-02 15:28:19 -07:00
module.c	modules: warn about suspicious return values from module's ->init() hook	2008-03-10 18:01:20 -07:00
mutex-debug.c	kernel: remove fastcall in kernel/*	2008-02-08 09:22:31 -08:00
mutex-debug.h
mutex.c	kernel: remove fastcall in kernel/*	2008-02-08 09:22:31 -08:00
mutex.h
notifier.c	kernel/notifier.c should #include <linux/reboot.h>	2008-02-06 10:41:02 -08:00
ns_cgroup.c	cgroups: implement namespace tracking subsystem	2007-10-19 11:53:37 -07:00
nsproxy.c	namespaces: move the IPC namespace under IPC_NS option	2008-02-08 09:22:23 -08:00
panic.c	ACPI: Taint kernel on ACPI table override (format corrected)	2008-02-06 22:07:51 -05:00
params.c	Add new string functions strict_strto* and convert kernel params to use them	2008-02-08 09:22:41 -08:00
pid.c	kernel: remove fastcall in kernel/*	2008-02-08 09:22:31 -08:00
pid_namespace.c	namespaces: cleanup the code managed with PID_NS option	2008-02-08 09:22:23 -08:00
pm_qos_params.c	pm qos infrastructure and interface	2008-02-05 09:44:22 -08:00
posix-cpu-timers.c	Use find_task_by_vpid in posix timers	2008-02-08 09:22:41 -08:00
posix-timers.c	hrtimer: check relative timeouts for overflow	2008-02-14 22:08:30 +01:00
printk.c	Make printk() console semaphore accesses sensible	2008-03-24 19:25:08 -07:00
profile.c	Nuke a duplicate include from profile.c	2008-02-08 09:22:34 -08:00
ptrace.c	ptrace_check_attach: remove unneeded ->signal != NULL check	2008-02-08 09:22:26 -08:00
rcuclassic.c	Preempt-RCU: implementation	2008-01-25 21:08:24 +01:00
rcupdate.c	rcupdate: fix comment	2008-02-13 16:21:18 -08:00
rcupreempt.c	rcupreempt: remove never-migrates assumption from rcu_process_callbacks()	2008-02-29 20:21:13 +01:00
rcupreempt_trace.c	Preempt-RCU: implementation	2008-01-25 21:08:24 +01:00
rcutorture.c	cpu-hotplug: replace lock_cpu_hotplug() with get_online_cpus()	2008-01-25 21:08:02 +01:00
relay.c	relay: set an spd_release() hook for splice	2008-03-26 12:04:09 +01:00
res_counter.c	Memory Resource Controller use strstrip while parsing arguments	2008-03-04 16:35:09 -08:00
resource.c	[POWERPC] Add arch-specific walk_memory_remove() for 64-bit powerpc	2008-02-08 19:52:48 +11:00
rtmutex-debug.c	Don't operate with pid_t in rtmutex tester	2008-02-08 09:22:41 -08:00
rtmutex-debug.h
rtmutex-tester.c	Driver core: change sysdev classes to use dynamic kobject names	2008-01-24 20:40:40 -08:00
rtmutex.c	hrtimer: more hrtimer_init_sleeper() fallout.	2008-02-13 15:45:36 +01:00
rtmutex.h
rtmutex_common.h	Don't operate with pid_t in rtmutex tester	2008-02-08 09:22:41 -08:00
rwsem.c	sched: mark rwsem functions as __sched for wchan/profiling	2007-12-18 15:21:13 +01:00
sched.c	NOHZ: reevaluate idle sleep length after add_timer_on()	2008-03-26 08:28:55 +01:00
sched_debug.c	sched: improve affine wakeups	2008-03-19 04:27:53 +01:00
sched_fair.c	sched: cleanup old and rarely used 'debug' features.	2008-03-21 16:43:47 +01:00
sched_idletask.c	sched: high-res preemption tick	2008-01-25 21:08:29 +01:00
sched_rt.c	sched: balance RT task resched only on runqueue	2008-03-07 16:43:00 +01:00
sched_stats.h	sched: clean up kernel/sched_stat.h	2007-11-28 15:52:56 +01:00
seccomp.c	make seccomp zerocost in schedule	2007-07-16 09:05:50 -07:00
signal.c	freezer vs stopped or traced	2008-03-04 07:59:54 -08:00
softirq.c	rcu: add support for dynamic ticks and preempt rcu	2008-02-29 18:46:50 +01:00
softlockup.c	softlockup: fix task state setting	2008-02-29 18:46:53 +01:00
spinlock.c	spinlock: lockbreak cleanup	2008-01-30 13:31:20 +01:00
srcu.c	make srcu_readers_active() static	2008-02-06 10:41:02 -08:00
stacktrace.c
stop_machine.c	stopmachine: semaphore to mutex	2008-02-06 10:41:08 -08:00
sys.c	Pidns: make full use of xxx_vnr() calls	2008-02-08 09:22:29 -08:00
sys_ni.c	timerfd: new timerfd API	2008-02-05 09:44:07 -08:00
sysctl.c	sched: revert load_balance_monitor() changes	2008-03-04 17:54:06 +01:00
sysctl_check.c	constify tables in kernel/sysctl_check.c	2008-02-08 09:22:31 -08:00
taskstats.c	kernel/taskstats.c: fix bogus nlmsg_free()	2007-11-14 18:45:44 -08:00
test_kprobes.c	kprobes: kretprobe user entry-handler	2008-02-06 10:41:11 -08:00
time.c	avoid overflows in kernel/time.c	2008-02-08 09:22:39 -08:00
timeconst.pl	timeconst.pl: correct reversal of USEC_TO_HZ and HZ_TO_USEC	2008-02-12 14:29:26 -08:00
timer.c	NOHZ: reevaluate idle sleep length after add_timer_on()	2008-03-26 08:28:55 +01:00
tsacct.c	Add scaled time to taskstats based process accounting	2007-10-18 14:37:28 -07:00
uid16.c	header cleaning: don't include smp_lock.h when not used	2007-05-08 11:15:07 -07:00
user.c	sched: rt-group: make rt groups scheduling configurable	2008-02-13 15:45:40 +01:00
user_namespace.c	namespaces: cleanup the code managed with the USER_NS option	2008-02-08 09:22:23 -08:00
utsname.c	Fix UTS corruption during clone(CLONE_NEWUTS)	2007-09-19 11:24:17 -07:00
utsname_sysctl.c	Isolate the UTS namespace's domainname and hostname back	2007-11-29 09:24:53 -08:00
wait.c	kernel: remove fastcall in kernel/*	2008-02-08 09:22:31 -08:00
workqueue.c	workqueue: make delayed_work_timer_fn() static	2008-02-08 09:22:37 -08:00