Steven Rostedt af52a90a14 sched_clock: stop maximum check on NO HZ ... Working with ftrace I would get large jumps of 11 millisecs or more with the clock tracer. This killed the latencing timings of ftrace and also caused the irqoff self tests to fail. What was happening is with NO_HZ the idle would stop the jiffy counter and before the jiffy counter was updated the sched_clock would have a bad delta jiffies to compare with the gtod with the maximum. The jiffies would stop and the last sched_tick would record the last gtod. On wakeup, the sched clock update would compare the gtod + delta jiffies (which would be zero) and compare it to the TSC. The TSC would have correctly (with a stable TSC) moved forward several jiffies. But because the jiffies has not been updated yet the clock would be prevented from moving forward because it would appear that the TSC jumped too far ahead. The clock would then virtually stop, until the jiffies are updated. Then the next sched clock update would see that the clock was very much behind since the delta jiffies is now correct. This would then jump the clock forward by several jiffies. This caused ftrace to report several milliseconds of interrupts off latency at every resume from NO_HZ idle. This patch adds hooks into the nohz code to disable the checking of the maximum clock update when nohz is in effect. It resumes the max check when nohz has updated the jiffies again. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Cc: Steven Rostedt <srostedt@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>		2008-07-11 15:53:26 +02:00
..
irq	genirq: reenable a nobody cared disabled irq when a new driver arrives	2008-05-02 13:40:34 +02:00
power	Merge branches 'release', 'acpica', 'bugzilla-10224', 'bugzilla-9772', 'bugzilla-9916', 'ec', 'eeepc', 'idle', 'misc', 'pm-legacy', 'sysfs-links-2.6.26', 'thermal', 'thinkpad' and 'video' into release	2008-04-30 13:58:00 -04:00
time	sched_clock: stop maximum check on NO HZ	2008-07-11 15:53:26 +02:00
.gitignore
acct.c
audit_tree.c	[PATCH] list_for_each_rcu must die: audit	2008-05-17 03:30:23 -04:00
audit.c	[PATCH] remove useless argument type in audit_filter_user()	2008-06-24 23:36:35 -04:00
audit.h	[PATCH 1/2] audit: move extern declarations to audit.h	2008-04-28 06:28:04 -04:00
auditfilter.c	[PATCH] remove useless argument type in audit_filter_user()	2008-06-24 23:36:35 -04:00
auditsc.c	[PATCH] new predicate - AUDIT_FILETYPE	2008-04-28 06:28:37 -04:00
backtracetest.c
bounds.c	Add kbuild.h that contains common definitions for kbuild users	2008-04-29 08:06:29 -07:00
capability.c	security: filesystem capabilities: fix fragile setuid fixup code	2008-07-04 10:40:08 -07:00
cgroup_debug.c	CGroup API files: move "releasable" to cgroup_debug subsystem	2008-04-29 08:06:09 -07:00
cgroup.c	cgroups: remove node_ prefix_from ns subsystem	2008-05-24 09:56:14 -07:00
compat.c	ntp: support for TAI	2008-05-01 08:03:59 -07:00
configs.c	kernel: use non-racy method for proc entries creation	2008-04-29 08:06:22 -07:00
cpu.c	kernel: replace remaining __FUNCTION__ occurrences	2008-04-30 08:29:54 -07:00
cpuset.c	Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2008-06-20 12:37:13 -07:00
delayacct.c
dma.c	kernel: use non-racy method for proc entries creation	2008-04-29 08:06:22 -07:00
exec_domain.c
exit.c	signals: fix sigqueue_free() vs __exit_signal() race	2008-05-24 09:56:10 -07:00
extable.c
fork.c	[PATCH] dup_fd() fixes, part 1	2008-05-16 17:22:26 -04:00
futex_compat.c
futex.c	futexes: fix fault handling in futex_lock_pi	2008-06-23 13:31:15 +02:00
hrtimer.c	hrtimer: prevent migration for raising softirq	2008-07-03 11:36:48 -07:00
itimer.c
kallsyms.c	kernel: use non-racy method for proc entries creation	2008-04-29 08:06:22 -07:00
Kconfig.hz
Kconfig.preempt
kexec.c	kexec: make extended crashkernel= syntax less confusing	2008-05-01 08:04:00 -07:00
kfifo.c
kgdb.c	kgdb: sparse fix	2008-06-24 10:52:55 -05:00
kmod.c	[PATCH] split linux/file.h	2008-05-01 13:08:16 -04:00
kprobes.c	kernel/kprobes.c: Made kprobe_blacklist static.	2008-07-10 10:13:51 -07:00
ksysfs.c
kthread.c	Deprecate find_task_by_pid()	2008-04-30 08:29:48 -07:00
latencytop.c	kernel: use non-racy method for proc entries creation	2008-04-29 08:06:22 -07:00
lockdep_internals.h
lockdep_proc.c	kernel: use non-racy method for proc entries creation	2008-04-29 08:06:22 -07:00
lockdep.c
Makefile	sched: add optional support for CONFIG_HAVE_UNSTABLE_SCHED_CLOCK	2008-05-05 23:56:18 +02:00
marker.c	make marker_debug static	2008-04-30 08:29:49 -07:00
module.c	modules: proper cleanup of kobject without CONFIG_SYSFS	2008-05-23 13:09:33 +10:00
mutex-debug.c
mutex-debug.h
mutex.c
mutex.h
notifier.c	ipc: re-enable msgmni automatic recomputing msgmni if set to negative	2008-04-29 08:06:13 -07:00
ns_cgroup.c	cgroups: kernel/ns_cgroup.c should #include <linux/nsproxy.h>	2008-04-29 08:06:07 -07:00
nsproxy.c	ipc: sysvsem: refuse clone(CLONE_SYSVSEM|CLONE_NEWIPC)	2008-04-29 08:06:14 -07:00
panic.c	Taint kernel after WARN_ON(condition)	2008-04-29 08:05:59 -07:00
params.c
pid_namespace.c	pidns: make pid->level and pid_ns->level unsigned	2008-04-30 08:29:49 -07:00
pid.c	pids: introduce change_pid() helper	2008-04-30 08:29:48 -07:00
pm_qos_params.c
posix-cpu-timers.c	remove div_long_long_rem	2008-05-01 08:03:58 -07:00
posix-timers.c	signals: join send_sigqueue() with send_group_sigqueue()	2008-04-30 08:29:36 -07:00
printk.c	kernel/printk.c: Made printk_recursion_bug_msg static.	2008-07-08 18:10:34 -07:00
profile.c	kernel: use non-racy method for proc entries creation	2008-04-29 08:06:22 -07:00
ptrace.c	make generic sys_ptrace unconditional	2008-05-01 10:21:54 -07:00
rcuclassic.c	rcu: fix hotplug vs rcu race	2008-07-01 09:27:17 +02:00
rcupdate.c
rcupreempt_trace.c
rcupreempt.c	Fix PREEMPT_RCU without HOTPLUG_CPU	2008-07-10 11:13:44 -07:00
rcutorture.c	kernel: explicitly include required header files under kernel/	2008-04-29 08:06:04 -07:00
relay.c	splice: fix sendfile() issue with relay	2008-05-28 14:49:27 +02:00
res_counter.c	memcgroup: add the max_usage member on the res_counter	2008-04-29 08:06:10 -07:00
resource.c	kernel: use non-racy method for proc entries creation	2008-04-29 08:06:22 -07:00
rtmutex_common.h
rtmutex-debug.c
rtmutex-debug.h
rtmutex-tester.c
rtmutex.c
rtmutex.h
rwsem.c
sched_clock.c	sched_clock: stop maximum check on NO HZ	2008-07-11 15:53:26 +02:00
sched_debug.c	revert ("sched: fair-group: SMP-nice for group scheduling")	2008-05-29 11:28:57 +02:00
sched_fair.c	sched: stop wake_affine from causing serious imbalance	2008-05-29 11:29:20 +02:00
sched_features.h	sched: /debug/sched_features	2008-04-19 19:45:00 +02:00
sched_idletask.c	sched: make rt_sched_class, idle_sched_class static	2008-05-05 23:56:17 +02:00
sched_rt.c	sched: rt: dont stop the period timer when there are tasks wanting to run	2008-06-20 11:00:19 +02:00
sched_stats.h	sched, delay accounting: fix incorrect delay time when constantly waiting on runqueue	2008-06-19 14:15:28 +02:00
sched.c	sched: fix divide error when trying to configure rt_period to zero	2008-07-01 08:23:24 +02:00
seccomp.c
semaphore.c	Revert "semaphore: fix"	2008-05-10 20:43:22 -07:00
signal.c	posix timers: discard SI_TIMER signals on exec	2008-05-26 10:37:07 -07:00
softirq.c	Fix cpu hotplug problem in softirq code	2008-05-01 08:03:58 -07:00
softlockup.c	softlockup: print a module list on being stuck	2008-07-05 08:51:24 +02:00
spinlock.c
srcu.c
stacktrace.c
stop_machine.c	stop_machine: make stop_machine_run more virtualization friendly	2008-05-23 13:09:34 +10:00
sys_ni.c
sys.c	sys_prctl(): fix return of uninitialized value	2008-05-24 09:56:13 -07:00
sysctl_check.c
sysctl.c	[PATCH] avoid multiplication overflows and signedness issues for max_fds	2008-05-16 17:22:52 -04:00
taskstats.c	Use find_task_by_vpid in taskstats	2008-04-30 08:29:48 -07:00
test_kprobes.c
time.c	Make constants in kernel/timeconst.h fixed 64 bits	2008-05-02 16:18:42 -07:00
timeconst.pl	Make constants in kernel/timeconst.h fixed 64 bits	2008-05-02 16:18:42 -07:00
timer.c	debugobjects: add timer specific object debugging code	2008-04-30 08:29:53 -07:00
tsacct.c
uid16.c	asmlinkage_protect replaces prevent_tail_call	2008-04-10 17:28:26 -07:00
user_namespace.c	eCryptfs: make key module subsystem respect namespaces	2008-04-29 08:06:07 -07:00
user.c	alloc_uid: cleanup	2008-04-30 08:29:53 -07:00
utsname_sysctl.c
utsname.c	kernel: explicitly include required header files under kernel/	2008-04-29 08:06:04 -07:00
wait.c
workqueue.c	Christoph has moved	2008-07-04 10:40:04 -07:00