linux/kernel
Thomas Gleixner cd689985cf futex: Add bitset conditional wait/wakeup functionality
To allow the implementation of optimized rw-locks in user space, glibc
needs a possibility to select waiters for wakeup depending on a bitset
mask.

This requires two new futex OPs: FUTEX_WAIT_BITS and FUTEX_WAKE_BITS
These OPs are basically the same as FUTEX_WAIT and FUTEX_WAKE plus an
additional argument - a bitset. Further the FUTEX_WAIT_BITS OP is
expecting an absolute timeout value instead of the relative one, which
is used for the FUTEX_WAIT OP.

FUTEX_WAIT_BITS calls into the kernel with a bitset. The bitset is
stored in the futex_q structure, which is used to enqueue the waiter
into the hashed futex waitqueue.

FUTEX_WAKE_BITS also calls into the kernel with a bitset. The wakeup
function logically ANDs the bitset with the bitset stored in each
waiters futex_q structure. If the result is zero (i.e. none of the set
bits in the bitsets is matching), then the waiter is not woken up. If
the result is not zero (i.e. one of the set bits in the bitsets is
matching), then the waiter is woken.

The bitset provided by the caller must be non zero. In case the
provided bitset is zero the kernel returns EINVAL.

Internaly the new OPs are only extensions to the existing FUTEX_WAIT
and FUTEX_WAKE functions. The existing OPs hand a bitset with all bits
set into the futex_wait() and futex_wake() functions.

Signed-off-by: Thomas Gleixner <tgxl@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-01 17:45:14 +01:00
..
irq genirq: stackdump after the "Trying to free already-free IRQ" message 2008-01-30 13:33:24 +01:00
power Merge branch 'task_killable' of git://git.kernel.org/pub/scm/linux/kernel/git/willy/misc 2008-02-01 11:45:47 +11:00
time tick-sched: add more debug information 2008-02-01 17:45:14 +01:00
.gitignore
acct.c acct: real_parent ppid 2008-01-07 14:55:37 -08:00
audit_tree.c [PATCH] audit: watching subtrees 2007-10-21 02:37:45 -04:00
audit.c [AUDIT]: Increase skb->truesize in audit_expand 2008-01-31 19:27:08 -08:00
audit.h [PATCH] audit: watching subtrees 2007-10-21 02:37:45 -04:00
auditfilter.c [PATCH] audit: watching subtrees 2007-10-21 02:37:45 -04:00
auditsc.c auditsc: fix kernel-doc param warnings 2007-10-22 19:40:02 -07:00
backtracetest.c x86: add a simple backtrace test module 2008-01-30 13:33:08 +01:00
capability.c Uninline find_pid etc set of functions 2007-10-19 11:53:41 -07:00
cgroup_debug.c Task Control Groups: simple task cgroup debug info subsystem 2007-10-19 11:53:36 -07:00
cgroup.c Improve cgroup printks 2007-11-14 18:45:37 -08:00
compat.c Merge ssh://master.kernel.org/pub/scm/linux/kernel/git/tglx/linux-2.6-hrt 2007-10-18 15:12:41 -07:00
configs.c use simple_read_from_buffer in kernel/ 2007-05-09 12:30:49 -07:00
cpu.c cpu-hotplug: replace per-subsystem mutexes with get_online_cpus() 2008-01-25 21:08:02 +01:00
cpuset.c cpu-hotplug: replace lock_cpu_hotplug() with get_online_cpus() 2008-01-25 21:08:02 +01:00
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 exit: Use task_is_* 2007-12-06 17:35:17 -05:00
extable.c module: Don't report discarded init pages as kernel text. 2008-01-29 17:13:18 +11:00
fork.c KVM: Disallow fork() and similar games when using a VM 2008-01-30 17:53:13 +02:00
futex_compat.c futex: Add bitset conditional wait/wakeup functionality 2008-02-01 17:45:14 +01:00
futex.c futex: Add bitset conditional wait/wakeup functionality 2008-02-01 17:45:14 +01:00
hrtimer.c hrtimer: fix hrtimer_init_sleeper() users 2008-02-01 17:45:13 +01:00
itimer.c whitespace fixes: interval timers 2007-10-18 14:37:26 -07:00
kallsyms.c module: make module_address_lookup safe 2008-01-29 17:13:23 +11:00
Kconfig.hz sched: high-res preemption tick 2008-01-25 21:08:29 +01:00
Kconfig.instrumentation Tiny clean-up of OPROFILE/KPROBES configuration 2007-12-06 09:41:12 -08:00
Kconfig.preempt sched: remove the !PREEMPT_BKL code 2008-01-25 21:08:33 +01:00
kexec.c vmcoreinfo: add the array length of "free_list" for filtering free pages 2008-01-08 16:10:36 -08:00
kfifo.c is_power_of_2: kernel/kfifo.c 2007-07-16 09:05:50 -07:00
kmod.c Fix unbalanced helper_lock in kernel/kmod.c 2008-01-17 15:38:59 -08:00
kprobes.c x86: kprobes: add kprobes smoke tests that run on boot 2008-01-30 13:32:53 +01:00
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
latency.c [PATCH] severing module.h->sched.h 2006-12-04 02:00:22 -05:00
latencytop.c sched: latencytop support 2008-01-25 21:08:34 +01:00
lockdep_internals.h [PATCH] lockdep: more chains 2006-12-07 08:39:43 -08:00
lockdep_proc.c lockdep: Avoid /proc/lockdep & lock_stat infinite output 2007-10-11 22:11:11 +02:00
lockdep.c softlockup: automatically detect hung TASK_UNINTERRUPTIBLE tasks 2008-01-25 21:08:02 +01:00
Makefile x86: add a simple backtrace test module 2008-01-30 13:33:08 +01:00
marker.c Linux Kernel Markers: fix marker mutex not taken upon module load 2007-11-14 18:45:40 -08:00
module.c x86/non-x86: percpu, node ids, apic ids x86.git fixup 2008-01-30 13:33:32 +01:00
mutex-debug.c [PATCH] remove many unneeded #includes of sched.h 2007-02-14 08:09:54 -08:00
mutex-debug.h [PATCH] lockdep: better lock debugging 2006-07-03 15:27:01 -07:00
mutex.c Add mutex_lock_killable 2007-12-06 17:37:59 -05:00
mutex.h [PATCH] lockdep: prove mutex locking correctness 2006-07-03 15:27:04 -07:00
notifier.c Add kernel/notifier.c 2007-10-19 11:53:34 -07:00
ns_cgroup.c cgroups: implement namespace tracking subsystem 2007-10-19 11:53:37 -07:00
nsproxy.c pid namespaces: allow cloning of new namespace 2007-10-19 11:53:39 -07:00
panic.c debug: add the end-of-trace marker and the module list to 2008-01-30 13:32:50 +01:00
params.c module: fix the module name length in param_sysfs_builtin 2008-01-29 17:13:24 +11:00
pid.c pidns: Place under CONFIG_EXPERIMENTAL 2007-11-14 18:45:43 -08:00
posix-cpu-timers.c sched: rt-watchdog: fix .rlim_max = RLIM_INFINITY 2008-01-25 21:08:32 +01:00
posix-timers.c Isolate some explicit usage of task->tgid 2007-10-19 11:53:40 -07:00
printk.c debug: turn ignore_loglevel into an early param 2008-01-31 22:45:23 +01:00
profile.c debug: clean up kernel/profile.c 2008-01-25 21:08:33 +01:00
ptrace.c Merge branch 'task_killable' of git://git.kernel.org/pub/scm/linux/kernel/git/willy/misc 2008-02-01 11:45:47 +11:00
rcuclassic.c Preempt-RCU: implementation 2008-01-25 21:08:24 +01:00
rcupdate.c Preempt-RCU: fix rcu_barrier for preemptive environment. 2008-01-25 21:08:24 +01:00
rcupreempt_trace.c Preempt-RCU: implementation 2008-01-25 21:08:24 +01:00
rcupreempt.c Preempt-RCU: CPU Hotplug handling 2008-01-25 21:08:25 +01:00
rcutorture.c cpu-hotplug: replace lock_cpu_hotplug() with get_online_cpus() 2008-01-25 21:08:02 +01:00
relay.c whitespace fixes: relayfs 2007-10-18 14:37:24 -07:00
resource.c Add IORESOUCE_BUSY flag for System RAM 2007-11-14 18:45:39 -08:00
rtmutex_common.h FUTEX: Tidy up the code 2007-07-16 09:05:49 -07:00
rtmutex-debug.c Use helpers to obtain task pid in printks 2007-10-19 11:53:43 -07:00
rtmutex-debug.h [PATCH] lockdep: better lock debugging 2006-07-03 15:27:01 -07:00
rtmutex-tester.c Driver core: change sysdev classes to use dynamic kobject names 2008-01-24 20:40:40 -08:00
rtmutex.c Use helpers to obtain task pid in printks 2007-10-19 11:53:43 -07:00
rtmutex.h [PATCH] lockdep: better lock debugging 2006-07-03 15:27:01 -07:00
rwsem.c sched: mark rwsem functions as __sched for wchan/profiling 2007-12-18 15:21:13 +01:00
sched_debug.c sched: keep total / count stats in addition to the max for 2008-01-25 21:08:35 +01:00
sched_fair.c sched: let +nice tasks have smaller impact 2008-01-31 22:45:22 +01:00
sched_idletask.c sched: high-res preemption tick 2008-01-25 21:08:29 +01:00
sched_rt.c sched: fix goto retry in pick_next_task_rt() 2008-01-25 21:08:34 +01:00
sched_stats.h sched: clean up kernel/sched_stat.h 2007-11-28 15:52:56 +01:00
sched.c Merge branch 'task_killable' of git://git.kernel.org/pub/scm/linux/kernel/git/willy/misc 2008-02-01 11:45:47 +11:00
seccomp.c make seccomp zerocost in schedule 2007-07-16 09:05:50 -07:00
signal.c Ensure that we export __fatal_signal_pending() 2008-02-01 12:58:14 +11:00
softirq.c time: track accurate idle time with tick_sched.idle_sleeptime 2008-01-30 13:30:04 +01:00
softlockup.c softlockup: fix signedness 2008-01-25 21:08:34 +01:00
spinlock.c spinlock: lockbreak cleanup 2008-01-30 13:31:20 +01:00
srcu.c [PATCH] SRCU: report out-of-memory errors 2006-10-04 07:55:30 -07:00
stacktrace.c [PATCH] lockdep: stacktrace subsystem, core 2006-07-03 15:27:02 -07:00
stop_machine.c cpu-hotplug: replace lock_cpu_hotplug() with get_online_cpus() 2008-01-25 21:08:02 +01:00
sys_ni.c [POWERPC] Provide a way to protect 4k subpages when using 64k pages 2008-01-24 10:06:01 +11:00
sys.c x86: ignore the sys_getcpu() tcache parameter 2007-11-17 16:27:00 +01:00
sysctl_check.c sysctl: Infrastructure for per namespace sysctls 2008-01-28 14:55:17 -08:00
sysctl.c x86: various changes and cleanups to in_p/out_p delay details 2008-01-30 13:30:05 +01:00
taskstats.c kernel/taskstats.c: fix bogus nlmsg_free() 2007-11-14 18:45:44 -08:00
test_kprobes.c x86: kprobes: add kprobes smoke tests that run on boot 2008-01-30 13:32:53 +01:00
time.c timekeeping: update xtime_cache when time(zone) changes 2008-02-01 17:45:13 +01:00
timer.c Merge branch 'task_killable' of git://git.kernel.org/pub/scm/linux/kernel/git/willy/misc 2008-02-01 11:45:47 +11:00
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_namespace.c Fix user namespace exiting OOPs 2007-09-19 11:24:18 -07:00
user.c uids: merge multiple error paths in alloc_uid() into one 2008-01-25 21:08:26 +01:00
utsname_sysctl.c Isolate the UTS namespace's domainname and hostname back 2007-11-29 09:24:53 -08:00
utsname.c Fix UTS corruption during clone(CLONE_NEWUTS) 2007-09-19 11:24:17 -07:00
wait.c wait: Use TASK_NORMAL 2007-12-06 17:34:36 -05:00
workqueue.c cpu-hotplug: replace per-subsystem mutexes with get_online_cpus() 2008-01-25 21:08:02 +01:00