Star64_linux/kernel
Tejun Heo c68eee14ec async: use ULLONG_MAX for infinity cookie value
Currently, next_cookie is used as the infinity value.  In most cases,
this should work fine but it theoretically could bring subtle behavior
difference between async_synchronize_full() and
async_synchronize_full_domain().

async_synchronize_full() keeps waiting until there's no registered
async_entry left regardless of what next_cookie was when the function
was called.  It guarantees that the queue is completely drained at
least once before returning.

However, async_synchronize_full_domain() doesn't.  It synchronizes
upto next_cookie and if further async jobs are queued after the
next_cookie value to synchronize is decided, they won't be waited for.

For unrelated async jobs, the behavior difference doesn't matter;
however, if async jobs which are related (nested or otherwise) to the
executing ones are queued while sychronization is in progress, the
resulting behavior difference could be problematic.

This can be easily fixed by using ULLONG_MAX as the infinity value
instead.  Define ASYNC_COOKIE_MAX as ULLONG_MAX and use it as the
infinity value for synchronization.  This makes
async_synchronize_full_domain() fully drain the domain at least once
before returning, making its behavior match async_synchronize_full().

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Dan Williams <djbw@fb.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
2013-01-23 09:32:30 -08:00
..
debug module: add new state MODULE_STATE_UNFORMED. 2013-01-12 13:27:05 +10:30
events Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2012-12-17 15:44:47 -08:00
gcov
irq irq: tsk->comm is an array 2012-12-18 15:02:11 -08:00
power Merge branch 'for-3.8' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2012-12-12 08:18:24 -08:00
sched Merge branch 'master' into for-3.9-async 2013-01-23 09:31:01 -08:00
time Merge tag 'kvm-3.8-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm 2012-12-13 15:31:08 -08:00
trace ftrace: Be first to run code modification on modules 2013-01-21 13:21:50 -05:00
.gitignore
acct.c
async.c async: use ULLONG_MAX for infinity cookie value 2013-01-23 09:32:30 -08:00
audit.c kernel/audit.c: avoid negative sleep durations 2013-01-11 14:54:56 -08:00
audit.h
audit_tree.c audit: catch possible NULL audit buffers 2013-01-11 14:54:55 -08:00
audit_watch.c audit: catch possible NULL audit buffers 2013-01-11 14:54:55 -08:00
auditfilter.c audit: fix auditfilter.c kernel-doc warnings 2013-01-10 14:35:23 -08:00
auditsc.c audit: catch possible NULL audit buffers 2013-01-11 14:54:55 -08:00
backtracetest.c
bounds.c
capability.c
cgroup.c Merge branch 'akpm' (Andrew's patch-bomb) 2012-12-17 20:58:12 -08:00
cgroup_freezer.c
compat.c x32: fix sigtimedwait 2012-12-26 01:15:03 -05:00
configs.c
context_tracking.c context_tracking: New context tracking susbsystem 2012-11-30 11:40:07 -08:00
cpu.c Merge branch 'x86-bsp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-12-11 19:56:33 -08:00
cpu_pm.c
cpuset.c cpuset: use N_MEMORY instead N_HIGH_MEMORY 2012-12-12 17:38:32 -08:00
crash_dump.c
cred.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2012-12-18 10:55:28 -08:00
delayacct.c
dma.c
elfcore.c
exec_domain.c
exit.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2012-12-17 15:44:47 -08:00
extable.c
fork.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal 2013-01-20 13:58:48 -08:00
freezer.c
futex.c
futex_compat.c
groups.c
hrtimer.c
hung_task.c
irq_work.c
itimer.c
jump_label.c
kallsyms.c
kcmp.c kcmp: include linux/ptrace.h 2012-12-20 17:40:19 -08:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kexec.c
kfifo.c
kmod.c Merge branch 'master' into for-3.9-async 2013-01-23 09:31:01 -08:00
kprobes.c
ksysfs.c Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-12-11 18:10:49 -08:00
kthread.c kthread: use N_MEMORY instead N_HIGH_MEMORY 2012-12-12 17:38:33 -08:00
latencytop.c
lglock.c
lockdep.c
lockdep_internals.h
lockdep_proc.c
lockdep_states.h
Makefile Nothing all that exciting; a new module-from-fd syscall for those who want 2012-12-19 07:55:08 -08:00
modsign_certificate.S MODSIGN: Avoid using .incbin in C source 2012-12-14 13:06:44 +10:30
modsign_pubkey.c keys: use keyring_alloc() to create module signing keyring 2012-12-20 17:40:21 -08:00
module-internal.h
module.c module: fix missing module_mutex unlock 2013-01-20 20:22:58 -08:00
module_signing.c MODSIGN: Don't use enum-type bitfields in module signature info block 2012-12-05 11:27:24 +10:30
mutex-debug.c
mutex-debug.h
mutex.c
mutex.h
notifier.c
nsproxy.c
padata.c padata: use __this_cpu_read per-cpu helper 2012-12-06 17:16:23 +08:00
panic.c
params.c
pid.c pidns: Stop pid allocation when init dies 2012-12-25 16:10:05 -08:00
pid_namespace.c pidns: Stop pid allocation when init dies 2012-12-25 16:10:05 -08:00
posix-cpu-timers.c A few /dev/random improvements for the v3.8 merge window. 2012-12-19 20:23:37 -08:00
posix-timers.c
printk.c printk: fix incorrect length from print_time() when seconds > 99999 2013-01-04 16:11:48 -08:00
profile.c propagate name change to comments in kernel source 2012-12-06 10:39:54 +01:00
ptrace.c ptrace: ensure arch_ptrace/ptrace_request can never race with SIGKILL 2013-01-22 10:08:00 -08:00
range.c
rcu.h
rcupdate.c
rcutiny.c
rcutiny_plugin.h
rcutorture.c
rcutree.c context_tracking: New context tracking susbsystem 2012-11-30 11:40:07 -08:00
rcutree.h
rcutree_plugin.h
rcutree_trace.c
relay.c
res_counter.c res_counter: return amount of charges after res_counter_uncharge() 2012-12-18 15:02:12 -08:00
resource.c
rtmutex-debug.c
rtmutex-debug.h
rtmutex-tester.c
rtmutex.c
rtmutex.h
rtmutex_common.h
rwsem.c lockdep, rwsem: provide down_write_nest_lock() 2013-01-11 14:54:55 -08:00
seccomp.c
semaphore.c
signal.c ptrace: ensure arch_ptrace/ptrace_request can never race with SIGKILL 2013-01-22 10:08:00 -08:00
smp.c
smpboot.c
smpboot.h
softirq.c
spinlock.c
srcu.c
stacktrace.c
stop_machine.c
sys.c
sys_ni.c module: add syscall to load module from fd 2012-12-14 13:05:22 +10:30
sysctl.c Automatic NUMA Balancing V11 2012-12-16 15:18:08 -08:00
sysctl_binary.c
task_work.c
taskstats.c
test_kprobes.c
time.c
timeconst.pl
timer.c
tracepoint.c
tsacct.c
uid16.c
up.c
user-return-notifier.c
user.c
user_namespace.c userns: Fix typo in description of the limitation of userns_install 2012-12-14 18:36:36 -08:00
utsname.c userns: Require CAP_SYS_ADMIN for most uses of setns. 2012-12-14 16:12:03 -08:00
utsname_sysctl.c
wait.c propagate name change to comments in kernel source 2012-12-06 10:39:54 +01:00
watchdog.c watchdog: Fix disable/enable regression 2012-12-19 12:10:33 -08:00
workqueue.c workqueue: move struct worker definition to workqueue_internal.h 2013-01-18 14:05:55 -08:00
workqueue_internal.h workqueue: implement current_is_async() 2013-01-18 14:05:56 -08:00