Mike Galbraith b5d9d734a5 sched: Ensure that a child can't gain time over it's parent after fork() ... A fork/exec load is usually "pass the baton", so the child should never be placed behind the parent. With START_DEBIT we make room for the new task, but with child_runs_first, that room comes out of the _parent's_ hide. There's nothing to say that the parent wasn't ahead of min_vruntime at fork() time, which means that the "baton carrier", who is essentially the parent in drag, can gain time and increase scheduling latencies for waiters. With NEW_FAIR_SLEEPERS + START_DEBIT + child_runs_first enabled, we essentially pass the sleeper fairness off to the child, which is fine, but if we don't base placement on the parent's updated vruntime, we can end up compounding latency woes if the child itself then does fork/exec. The debit incurred at fork doesn't hurt the parent who is then going to sleep and maybe exit, but the child who acquires the error harms all comers. This improves latencies of make -j<n> kernel build workloads. Reported-by: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Mike Galbraith <efault@gmx.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>		2009-09-08 13:15:34 +02:00
..
gcov	gcov: enable GCOV_PROFILE_ALL for x86_64	2009-06-18 13:03:58 -07:00
irq	genirq: Wake up irq thread after action has been installed	2009-08-18 17:22:43 +02:00
power	headers: smp_lock.h redux	2009-07-12 12:22:34 -07:00
time	clockevent: Prevent dead lock on clockevents_lock	2009-08-19 18:15:10 +02:00
trace	tracing: handle broken names in ftrace filter	2009-08-18 20:39:48 -04:00
.gitignore
acct.c	bsdacct: fix access to invalid filp in acct_on()	2009-06-30 18:56:00 -07:00
async.c	async: Fix lack of boot-time console due to insufficient synchronization	2009-06-08 12:31:53 -07:00
audit.c	Fix rule eviction order for AUDIT_DIR	2009-06-24 00:02:38 -04:00
audit.h	Fix rule eviction order for AUDIT_DIR	2009-06-24 00:02:38 -04:00
audit_tree.c	Fix rule eviction order for AUDIT_DIR	2009-06-24 00:02:38 -04:00
audit_watch.c	Audit: clean up all op= output to include string quoting	2009-06-24 00:00:52 -04:00
auditfilter.c	Audit: clean up all op= output to include string quoting	2009-06-24 00:00:52 -04:00
auditsc.c	Fix rule eviction order for AUDIT_DIR	2009-06-24 00:02:38 -04:00
backtracetest.c
bounds.c
capability.c
cgroup.c	cgroup avoid permanent sleep at rmdir	2009-07-29 19:10:35 -07:00
cgroup_debug.c	debug cgroup: remove unneeded cgroup_lock	2009-04-02 19:04:54 -07:00
cgroup_freezer.c
compat.c	signals: implement sys_rt_tgsigqueueinfo	2009-04-30 19:24:24 +02:00
configs.c
cpu.c	mm/init: cpu_hotplug_init() must be initialized before SLAB	2009-06-22 21:18:12 -07:00
cpuset.c	cpuset,mm: update tasks' mems_allowed in time	2009-06-16 19:47:31 -07:00
cred-internals.h
cred.c	CRED: Rename cred_exec_mutex to reflect that it's a guard against ptrace	2009-05-11 08:15:36 +10:00
delayacct.c
dma-coherent.c
dma.c
exec_domain.c	Get rid of indirect include of fs_struct.h	2009-03-31 23:00:27 -04:00
exit.c	headers: mnt_namespace.h redux	2009-07-08 09:31:56 -07:00
extable.c	Merge branch 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2009-04-05 11:04:19 -07:00
fork.c	clone(): fix race between copy_process() and de_thread()	2009-08-26 20:06:52 -07:00
freezer.c	sched: fix nr_uninterruptible accounting of frozen tasks really	2009-07-18 14:19:53 +02:00
futex.c	futex: Fix handling of bad requeue syscall pairing	2009-08-10 20:38:11 +02:00
futex_compat.c	futex: Fix compat_futex to be same as futex for REQUEUE_PI	2009-08-10 15:41:12 +02:00
groups.c	groups: move code to kernel/groups.c	2009-06-16 19:47:48 -07:00
hrtimer.c	hrtimer: Fix migration expiry check	2009-07-10 17:32:55 +02:00
hung_task.c	softlockup: ensure the task has been switched out once	2009-02-11 11:04:16 +01:00
itimer.c	timers: split process wide cpu clocks/timers	2009-02-05 13:04:33 +01:00
kallsyms.c	kernel/kallsyms.c: replace deprecated __initcall with device_initcall and fix whitespace	2009-06-09 22:37:52 +02:00
Kconfig.freezer
Kconfig.hz
Kconfig.preempt
kexec.c	kexec: fix omitting offset in extended crashkernel syntax	2009-07-29 19:10:34 -07:00
kfifo.c	kernel/kfifo.c: replace conditional test with is_power_of_2()	2009-06-16 19:47:47 -07:00
kgdb.c	sysrq, intel_fb: fix sysrq g collision	2009-05-15 07:56:24 -05:00
kmod.c	headers: mnt_namespace.h redux	2009-07-08 09:31:56 -07:00
kprobes.c	kprobes: Use kernel_text_address() for checking probe address	2009-07-30 16:44:06 -07:00
ksysfs.c
kthread.c	update the comment in kthread_stop()	2009-07-27 12:15:46 -07:00
latencytop.c	sched, latencytop: incorporate review feedback from Andrew Morton	2009-02-11 10:18:04 +01:00
lockdep.c	Merge branch 'linus' into tracing/core	2009-05-07 11:17:34 +02:00
lockdep_internals.h	lockdep: increase MAX_LOCKDEP_ENTRIES and MAX_LOCKDEP_CHAINS	2009-05-12 19:59:52 +02:00
lockdep_proc.c	lockdep: Fix file mode of lock_stat	2009-08-07 11:58:38 +02:00
lockdep_states.h	lockdep: move state bit definitions around	2009-02-14 23:27:59 +01:00
Makefile	Merge branch 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2009-06-28 11:05:04 -07:00
marker.c
module.c	module: workaround duplicate section names	2009-08-27 12:33:19 -07:00
mutex-debug.c
mutex-debug.h
mutex.c	Merge branch 'linus' into perfcounters/core	2009-06-11 17:55:42 +02:00
mutex.h
notifier.c
ns_cgroup.c	cgroups: relax ns_can_attach checks to allow attaching to grandchild cgroups	2009-04-02 19:04:53 -07:00
nsproxy.c	nsproxy: extract create_nsproxy()	2009-06-18 13:03:56 -07:00
panic.c	trace: stop tracer in oops_enter()	2009-07-24 15:30:45 -04:00
params.c	module_param: allow 'bool' module_params to be bool, not just int.	2009-06-12 21:46:58 +09:30
perf_counter.c	perf_counter: Fix typo in read() output generation	2009-08-21 18:00:35 +02:00
pid.c	kmemleak: Remove alloc_bootmem annotations introduced in the past	2009-07-09 17:07:02 +01:00
pid_namespace.c	pidns: rewrite copy_pid_ns()	2009-06-18 13:03:55 -07:00
pm_qos_params.c
posix-cpu-timers.c	posix_cpu_timers_exit_group(): Do not use thread_group_cputimer()	2009-08-08 18:30:25 +02:00
posix-timers.c	posix-timers: Fix oops in clock_nanosleep() with CLOCK_MONOTONIC_RAW	2009-08-04 10:16:41 +02:00
printk.c	printk: Add KERN_DEFAULT printk log-level	2009-06-16 11:02:28 -07:00
profile.c	profile: suppress warning about large allocations when profile=1 is specified	2009-07-29 19:10:36 -07:00
ptrace.c	cred_guard_mutex: do not return -EINTR to user-space	2009-07-06 13:57:04 -07:00
rcuclassic.c	kmemtrace, rcu: fix linux/rcutree.h and linux/rcuclassic.h dependencies	2009-04-03 12:23:02 +02:00
rcupdate.c	RCU: Don't try and predeclare inline funcs as it upsets some versions of gcc	2009-04-15 13:55:14 -07:00
rcupreempt.c	rcu: rcu_sched_grace_period(): kill the bogus flush_signals()	2009-05-05 20:28:05 +02:00
rcupreempt_trace.c
rcutorture.c	cpumask: convert rcutorture.c	2009-03-30 22:05:16 +10:30
rcutree.c	rcu: Mark Hierarchical RCU no longer experimental	2009-06-24 15:02:48 +02:00
rcutree.h	kmemtrace, rcu: fix rcu_tree_trace.c data structure dependencies	2009-04-03 12:23:03 +02:00
rcutree_trace.c	rcu: Add __rcu_pending tracing to hierarchical RCU	2009-04-14 11:33:43 +02:00
relay.c	Merge branch 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2009-04-05 11:04:19 -07:00
res_counter.c	memcg: add interface to reset limits	2009-06-18 13:03:48 -07:00
resource.c	kernel/resource.c: fix sign extension in reserve_setup()	2009-06-30 18:56:00 -07:00
rtmutex-debug.c
rtmutex-debug.h
rtmutex-tester.c
rtmutex.c	rtmutex: Avoid deadlock in rt_mutex_start_proxy_lock()	2009-08-06 05:50:21 +02:00
rtmutex.h
rtmutex_common.h	rt_mutex: add proxy lock routines	2009-04-06 11:14:02 +02:00
rwsem.c
sched.c	sched: Fix dynamic power-balancing crash	2009-09-04 11:52:52 +02:00
sched_clock.c	sched: Fix fallback sched_clock()'s offset when using jiffies	2009-05-09 10:08:19 +02:00
sched_cpupri.c	sched: Add new prio to cpupri before removing old prio	2009-08-02 14:26:09 +02:00
sched_cpupri.h	cpumask: remove cpumask_t from core	2009-03-30 22:05:17 +10:30
sched_debug.c	sched: Provide iowait counters	2009-09-02 08:44:08 +02:00
sched_fair.c	sched: Ensure that a child can't gain time over it's parent after fork()	2009-09-08 13:15:34 +02:00
sched_features.h	Merge branch 'locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2009-03-30 17:17:35 -07:00
sched_idletask.c	sched, timers: move calc_load() to scheduler	2009-05-15 15:32:45 +02:00
sched_rt.c	sched: Scale down cpu_power due to RT tasks	2009-09-04 10:09:55 +02:00
sched_stats.h	sched: remove unused fields from struct rq	2009-03-24 23:16:51 +01:00
seccomp.c	x86-64: seccomp: fix 32/64 syscall hole	2009-03-02 15:41:30 -08:00
semaphore.c
signal.c	do_sigaltstack: small cleanups	2009-08-01 11:18:56 -07:00
slow-work.c	slow-work: use round_jiffies() for thread pool's cull and OOM timers	2009-06-16 19:47:49 -07:00
smp.c	generic-ipi: fix hotplug_cfd()	2009-08-07 10:39:55 -07:00
softirq.c	softirq: introduce tasklet_hrtimer infrastructure	2009-07-22 17:01:17 +02:00
softlockup.c
spinlock.c	Allow rwlocks to re-enable interrupts	2009-04-02 19:05:11 -07:00
srcu.c
stacktrace.c
stop_machine.c	cpumask: remove cpumask_t from core	2009-03-30 22:05:17 +10:30
sys.c	groups: move code to kernel/groups.c	2009-06-16 19:47:48 -07:00
sys_ni.c
sysctl.c	sched: Scale down cpu_power due to RT tasks	2009-09-04 10:09:55 +02:00
sysctl_check.c
taskstats.c
test_kprobes.c
time.c
timeconst.pl
timer.c	timer: Avoid reading uninitialized data	2009-07-18 23:11:43 +02:00
tracepoint.c	tracepoints: dont update zero-sized tracepoint sections	2009-03-18 19:55:00 +01:00
tsacct.c	Fix fixpoint divide exception in acct_update_integrals	2009-03-09 08:13:35 -07:00
uid16.c
up.c
user.c	sched: delayed cleanup of user_struct	2009-06-15 21:30:23 -07:00
user_namespace.c	Fix recursive lock in free_uid()/free_user_ns()	2009-02-27 16:26:21 -08:00
utsname.c	utsns: extract creeate_uts_ns()	2009-06-18 13:03:55 -07:00
utsname_sysctl.c	proc_sysctl: use CONFIG_PROC_SYSCTL around ipc and utsname proc_handlers	2009-04-02 19:05:01 -07:00
wait.c	locking, sched: Give waitqueue spinlocks their own lockdep classes	2009-08-10 14:43:09 +02:00
workqueue.c	ftrace, workqueuetrace: make workqueue tracepoints use TRACE_EVENT macro	2009-06-02 01:10:40 +02:00