Rik van Riel 2c13c919d9 sched: Limit the scope of clear_buddies ... The clear_buddies function does not seem to play well with the concept of hierarchical runqueues. In the following tree, task groups are represented by 'G', tasks by 'T', next by 'n' and last by 'l'. (nl) / \ G(nl) G / \ \ T(l) T(n) T This situation can arise when a task is woken up T(n), and the previously running task T(l) is marked last. When clear_buddies is called from either T(l) or T(n), the next and last buddies of the group G(nl) will be cleared. This is not the desired result, since we would like to be able to find the other type of buddy in many cases. This especially a worry when implementing yield_task_fair through the buddy system. The fix is simple: only clear the buddy type that the task itself is indicated to be. As an added bonus, we stop walking up the tree when the buddy has already been cleared or pointed elsewhere. Signed-off-by: Rik van Riel <riel@redhat.coM> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20110201094837.6b0962a9@annuminas.surriel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>		2011-02-03 14:20:32 +01:00
..
debug	Merge branch 'master' into for-next	2010-12-22 18:57:02 +01:00
gcov
irq	genirq: Remove __do_IRQ	2011-01-21 11:55:31 +01:00
power	Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6	2011-01-13 20:15:35 -08:00
time	hrtimers: Notify hrtimer users of switches to NOHZ mode	2011-01-19 20:08:15 +01:00
trace	lockdep: Move early boot local IRQ enable/disable status to init/main.c	2011-01-20 13:32:33 +01:00
.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	Merge branch 'vfs-scale-working' of git://git.kernel.org/pub/scm/linux/kernel/git/npiggin/linux-npiggin	2011-01-14 09:08:29 -08:00
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	thp: khugepaged	2011-01-13 17:32:43 -08:00
freezer.c	Freezer: Fix a race during freezing of TASK_STOPPED tasks	2010-12-24 15:02:40 +01:00
futex_compat.c
futex.c	Merge branches 'core-fixes-for-linus', 'x86-fixes-for-linus', 'timers-fixes-for-linus' and 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2011-01-15 12:45:00 -08:00
groups.c
hrtimer.c	Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial	2011-01-13 10:05:56 -08:00
hung_task.c
hw_breakpoint.c	perf: Dynamic pmu types	2010-12-16 11:36:43 +01:00
irq_work.c	irq_work: Use per cpu atomics instead of regular atomics	2010-12-18 15:54:48 +01:00
itimer.c
jump_label.c
kallsyms.c	Revert "kernel: make /proc/kallsyms mode 400 to reduce ease of attacking"	2010-11-19 11:54:40 -08:00
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	fs/proc/base.c, kernel/latencytop.c: convert sprintf_symbol() to %ps	2011-01-13 08:03:16 -08:00
lockdep_internals.h
lockdep_proc.c
lockdep_states.h
lockdep.c	lockdep: Move early boot local IRQ enable/disable status to init/main.c	2011-01-20 13:32:33 +01:00
Makefile	kernel: clean up USE_GENERIC_SMP_HELPERS	2011-01-13 08:03:08 -08:00
module.c	module: Move RO/NX module protection to after ftrace module update	2010-12-23 09:56:00 -05:00
mutex-debug.c
mutex-debug.h
mutex.c	mutexes, sched: Introduce arch_mutex_cpu_relax()	2010-11-26 15:05:34 +01:00
mutex.h
notifier.c
ns_cgroup.c
nsproxy.c
padata.c
panic.c	ACPI, APEI, Generic Hardware Error Source POLL/IRQ/NMI notification type support	2011-01-12 03:06:19 -05:00
params.c	module: show version information for built-in modules in sysfs	2011-01-24 14:32:51 +10:30
perf_event.c	perf: perf_event_exit_task_context: s/rcu_dereference/rcu_dereference_raw/	2011-01-21 22:08:16 +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	rcu: Distinguish between boosting and boosted	2010-11-29 22:01:56 -08:00
rcutiny.c	rcu: avoid pointless blocked-task warnings	2011-01-14 04:58:08 -08:00
rcutorture.c
rcutree_plugin.h	rcu: increase synchronize_sched_expedited() batching	2010-12-17 12:34:08 -08:00
rcutree_trace.c	rcu,cleanup: simplify the code when cpu is dying	2010-11-29 22:01:58 -08:00
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	rcu: limit rcu_node leaf-level fanout	2010-12-17 12:34:20 -08:00
relay.c
res_counter.c
resource.c	resources: add arch hook for preventing allocation in reserved areas	2010-12-17 10:01:09 -08:00
rtmutex_common.h
rtmutex-debug.c
rtmutex-debug.h
rtmutex-tester.c
rtmutex.c
rtmutex.h
rwsem.c
sched_autogroup.c	sched, autogroup: Fix CONFIG_RT_GROUP_SCHED sched_setscheduler() failure	2011-01-18 15:09:42 +01:00
sched_autogroup.h	sched, autogroup: Fix CONFIG_RT_GROUP_SCHED sched_setscheduler() failure	2011-01-18 15:09:42 +01:00
sched_clock.c	sched: Add some clock info to sched_debug	2010-11-23 10:29:08 +01:00
sched_cpupri.c
sched_cpupri.h
sched_debug.c	sched: Replace rq->bkl_count with rq->rq_sched_info.bkl_count	2011-01-18 15:09:43 +01:00
sched_fair.c	sched: Limit the scope of clear_buddies	2011-02-03 14:20:32 +01:00
sched_features.h
sched_idletask.c	sched: Fix switch_from_fair()	2011-01-26 12:33:22 +01:00
sched_rt.c	sched: Fix switch_from_fair()	2011-01-26 12:33:22 +01:00
sched_stats.h
sched_stoptask.c	sched: Fix switch_from_fair()	2011-01-26 12:33:22 +01:00
sched.c	sched: Avoid expensive initial update_cfs_load(), on UP too	2011-01-27 12:48:14 +01:00
seccomp.c
semaphore.c
signal.c
smp.c	Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2011-01-20 18:30:37 -08:00
softirq.c	softirqs: Free up pf flag PF_KSOFTIRQD	2011-01-26 12:33:20 +01:00
spinlock.c
srcu.c	rcu: demote SRCU_SYNCHRONIZE_DELAY from kernel-parameter status	2011-01-14 04:56:49 -08:00
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	Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial	2011-01-13 10:05:56 -08:00
sysctl_check.c
sysctl.c	sysctl: remove obsolete comments	2011-01-13 08:03:18 -08:00
taskstats.c	taskstats: use better ifdef for alignment	2011-01-13 08:03:19 -08:00
test_kprobes.c
time.c	time: Add nsecs_to_cputime64 interface for asm-generic	2011-01-26 12:33:20 +01:00
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_ns: improve the user_ns on-the-slab packaging	2011-01-13 08:03:18 -08:00
user-return-notifier.c
user.c	fix freeing user_struct in user cache	2010-12-29 11:31:38 -08:00
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	workqueue: note the nested NOT_RUNNING test in worker_clr_flags() isn't a noop	2011-01-11 16:03:14 +01:00