Repository files (latest commit first)

Filename	Latest commit message	Latest commit date
xiaofeng.yan 177ef2a631 sched/deadline: Fix a precision problem in the microseconds range ... An overrun could happen in function start_hrtick_dl() when a task with SCHED_DEADLINE runs in the microseconds range. For example, if a task with SCHED_DEADLINE has the following parameters: Task runtime deadline period P1 200us 500us 500us The deadline and period from task P1 are less than 1ms. In order to achieve microsecond precision, we need to enable HRTICK feature by the next command: PC#echo "HRTICK" > /sys/kernel/debug/sched_features PC#trace-cmd record -e sched_switch & PC#./schedtool -E -t 200000:500000:500000 -e ./test The binary test is in an endless while(1) loop here. Some pieces of trace.dat are as follows: <idle>-0 157.603157: sched_switch: :R ==> 2481:4294967295: test test-2481 157.603203: sched_switch: 2481:R ==> 0:120: swapper/2 <idle>-0 157.605657: sched_switch: :R ==> 2481:4294967295: test test-2481 157.608183: sched_switch: 2481:R ==> 2483:120: trace-cmd trace-cmd-2483 157.609656: sched_switch:2483:R==>2481:4294967295: test We can get the runtime of P1 from the information above: runtime = 157.608183 - 157.605657 runtime = 0.002526(2.526ms) The correct runtime should be less than or equal to 200us at some point. The problem is caused by a conditional judgment "delta > 10000" in function start_hrtick_dl(). Because no hrtimer start up to control the rest of runtime when the reset of runtime is less than 10us. So the process will continue to run until tick-period is coming. Move the code with the limit of the least time slice from hrtick_start_fair() to hrtick_start() because the EDF schedule class also needs this function in start_hrtick_dl(). To fix this problem, we call hrtimer_start() unconditionally in start_hrtick_dl(), and make sure the scheduling slice won't be smaller than 10us in hrtimer_start(). Signed-off-by: Xiaofeng Yan <xiaofeng.yan@huawei.com> Reviewed-by: Li Zefan <lizefan@huawei.com> Acked-by: Juri Lelli <juri.lelli@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1409022941-5880-1-git-send-email-xiaofeng.yan@huawei.com [ Massaged the changelog and the code. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>		2014-09-07 11:09:59 +02:00
..
debug	kernel/printk: use symbolic defines for console loglevels	2014-06-04 16:54:17 -07:00
events	Linux 3.16-rc7	2014-07-28 10:00:33 +02:00
gcov	gcov: add support for GCC 4.9	2014-06-10 15:34:46 -07:00
irq	genirq: Fix memory leak when calling irq_free_hwirqs()	2014-07-05 21:42:08 +02:00
locking	arch, locking: Ciao arch_mutex_cpu_relax()	2014-07-17 12:32:47 +02:00
power	This pull request has a lot of work done. The main thing is the changes	2014-08-04 11:50:00 -07:00
printk	kernel/printk/printk.c: revert "printk: enable interrupts before calling console_trylock_for_printk()"	2014-07-03 09:21:54 -07:00
rcu	Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2014-08-04 15:55:08 -07:00
sched	sched/deadline: Fix a precision problem in the microseconds range	2014-09-07 11:09:59 +02:00
time	Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2014-08-04 16:23:30 -07:00
trace	Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2014-08-04 16:09:53 -07:00
.gitignore
acct.c	ipc, kernel: clear whitespace	2014-06-06 16:08:14 -07:00
async.c
audit.c	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next	2014-06-12 14:27:40 -07:00
audit.h	audit: Use struct net not pid_t to remember the network namespce to reply in	2014-03-20 10:10:53 -04:00
audit_tree.c	inotify: Fix reporting of cookies for inotify events	2014-02-18 11:17:17 +01:00
audit_watch.c	inotify: Fix reporting of cookies for inotify events	2014-02-18 11:17:17 +01:00
auditfilter.c	Merge git://git.infradead.org/users/eparis/audit	2014-04-12 12:38:53 -07:00
auditsc.c	auditsc: audit_krule mask accesses need bounds checking	2014-06-10 08:44:40 -07:00
backtracetest.c	kernel/backtracetest.c: replace no level printk by pr_info()	2014-06-04 16:54:14 -07:00
bounds.c
capability.c	fs,userns: Change inode_capable to capable_wrt_inode_uidgid	2014-06-10 13:57:22 -07:00
cgroup.c	Merge branch 'for-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup	2014-08-04 10:11:28 -07:00
cgroup_freezer.c	cgroup: rename cgroup_subsys->base_cftypes to ->legacy_cftypes	2014-07-15 11:05:09 -04:00
compat.c	kernel/compat.c: use sizeof() instead of sizeof	2014-06-04 16:54:19 -07:00
configs.c
context_tracking.c	x86/kprobes: Fix build errors and blacklist context_track_user	2014-06-14 09:07:44 +02:00
cpu.c	sched: Rework check_for_tasks()	2014-07-05 11:17:45 +02:00
cpu_pm.c
cpuset.c	Merge branch 'for-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup	2014-08-04 10:11:28 -07:00
crash_dump.c
cred.c
delayacct.c
dma.c
elfcore.c
exec_domain.c	kernel/exec_domain.c: code clean-up	2014-06-04 16:54:15 -07:00
exit.c	signals: mv {dis,}allow_signal() from sched.h/exit.c to signal.[ch]	2014-06-06 16:08:11 -07:00
extable.c	asmlinkage: Make main_extable_sort_needed visible	2014-02-13 18:13:22 -08:00
fork.c	Linux 3.16-rc5	2014-07-16 15:10:07 +02:00
freezer.c
futex.c	futex: Simplify futex_lock_pi_atomic() and make it more robust	2014-06-21 22:26:24 +02:00
futex_compat.c	compat: Get rid of (get|put)_compat_time(val|spec)	2014-02-02 14:09:12 -08:00
groups.c	kernel/groups.c: remove return value of set_groups	2014-04-03 16:21:05 -07:00
hrtimer.c	Merge branch 'perf/urgent' into perf/core, to resolve conflict and to prepare for new patches	2014-06-06 07:55:06 +02:00
hung_task.c	kernel/hung_task.c: convert simple_strtoul to kstrtouint	2014-06-04 16:54:15 -07:00
irq_work.c	irq_work: Remove BUG_ON in irq_work_run()	2014-07-05 11:17:26 +02:00
itimer.c
jump_label.c
kallsyms.c	kernel: use macros from compiler.h instead of __attribute__((...))	2014-04-07 16:36:11 -07:00
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks	locking/rwsem: Add CONFIG_RWSEM_SPIN_ON_OWNER	2014-07-16 14:57:13 +02:00
Kconfig.preempt
kexec.c	kexec: fix build error when hugetlbfs is disabled	2014-07-30 20:09:37 -07:00
kmod.c	signals: change wait_for_helper() to use kernel_sigaction()	2014-06-06 16:08:12 -07:00
kprobes.c	kprobes: Fix "Failed to find blacklist" probing errors on ia64 and ppc64	2014-07-18 06:23:40 +02:00
ksysfs.c	kobject: Make support for uevent_helper optional.	2014-04-25 12:00:49 -07:00
kthread.c	kthread_work: wake up worker only when the worker is idle	2014-07-28 14:07:52 -04:00
latencytop.c	kernel/latencytop.c: convert seq_printf to seq_puts	2014-06-04 16:54:15 -07:00
Makefile	Merge branch 'x86-asmlinkage-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2014-03-31 14:13:25 -07:00
module-internal.h
module.c	crypto: fips - only panic on bad/missing crypto mod signatures	2014-07-03 21:38:32 +08:00
module_signing.c
notifier.c	kprobes, notifier: Use NOKPROBE_SYMBOL macro in notifier	2014-04-24 10:26:39 +02:00
nsproxy.c
padata.c
panic.c	kernel/panic.c: add "crash_kexec_post_notifiers" option for kdump after panic_notifers	2014-06-06 16:08:12 -07:00
params.c	param: hand arguments after -- straight to init	2014-04-28 11:48:34 +09:30
pid.c
pid_namespace.c	pid_namespace: pidns_get() should check task_active_pid_ns() != NULL	2014-04-02 16:20:21 -07:00
posix-cpu-timers.c
posix-timers.c
profile.c	kernel/profile.c: use static const char instead of static char	2014-06-06 16:08:13 -07:00
ptrace.c	sched: Remove proliferation of wait_on_bit() action functions	2014-07-16 15:10:39 +02:00
range.c
reboot.c	kernel/reboot.c: convert simple_strtoul to kstrtoint	2014-06-04 16:54:15 -07:00
relay.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2014-04-12 14:49:50 -07:00
res_counter.c	kernel/res_counter.c: replace simple_strtoull by kstrtoull	2014-06-04 16:54:15 -07:00
resource.c	resources: Clarify sanity check message	2014-05-23 10:47:21 -06:00
seccomp.c	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next	2014-06-12 14:27:40 -07:00
signal.c	signal: Explain local_irq_save() call	2014-07-09 09:14:33 -07:00
smp.c	Linux 3.16-rc5	2014-07-16 15:10:07 +02:00
smpboot.c
smpboot.h
softirq.c	Merge branch 'rcu/next' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu	2014-05-22 11:36:10 +02:00
stacktrace.c
stop_machine.c	kernel/stop_machine.c: kernel-doc warning fix	2014-06-04 16:54:15 -07:00
sys.c	sched: Consolidate open coded implementations of nice level frobbing into nice_to_rlimit() and rlimit_to_nice()	2014-05-22 11:16:36 +02:00
sys_ni.c	sys_sgetmask/sys_ssetmask: add CONFIG_SGETMASK_SYSCALL	2014-06-04 16:54:14 -07:00
sysctl.c	kernel/watchdog.c: print traces for all cpus on lockup detection	2014-06-23 16:47:44 -07:00
sysctl_binary.c
system_certificates.S
system_keyring.c
task_work.c
taskstats.c
test_kprobes.c
time.c
timeconst.bc
timer.c	timer: Prevent overflow in apply_slack	2014-04-30 13:46:17 +02:00
torture.c	torture: Avoid format string leak to thead name	2014-07-07 10:12:56 -07:00
tracepoint.c	tracing: syscall_regfunc() should not skip kernel threads	2014-06-21 00:15:26 -04:00
tsacct.c
uid16.c
up.c	smp: Rename __smp_call_function_single() to smp_call_function_single_async()	2014-02-24 14:47:15 -08:00
user-return-notifier.c
user.c	kernel/user.c: drop unused field 'files' from user_struct	2014-06-04 16:54:16 -07:00
user_namespace.c	kernel/user_namespace.c: kernel-doc/checkpatch fixes	2014-06-06 16:08:13 -07:00
utsname.c
utsname_sysctl.c	sysctl: convert use of typedef ctl_table to struct ctl_table	2014-06-06 16:08:16 -07:00
watchdog.c	kernel/watchdog.c: print traces for all cpus on lockup detection	2014-06-23 16:47:44 -07:00
workqueue.c	Merge branch 'for-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu	2014-08-04 10:09:27 -07:00
workqueue_internal.h	workqueue: rename manager_mutex to attach_mutex	2014-05-20 10:59:32 -04:00