Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-12-03 17:41:22 +00:00
Code Issues Packages Projects Releases Wiki Activity
2541117b0c
linux/kernel
History
Hiroshi Shimamoto 2541117b0c sched/cputime: Fix invalid gtime in proc 
/proc/stats shows invalid gtime when the thread is running in guest.
When vtime accounting is not enabled, we cannot get a valid delta.
The delta is calculated with now - tsk->vtime_snap, but tsk->vtime_snap
is only updated when vtime accounting is runtime enabled.

This patch makes task_gtime() just return gtime without computing the
buggy non-existing tickless delta when vtime accounting is not enabled.

Use context_tracking_is_enabled() to check if vtime is accounting on
some cpu, in which case only we need to check the tickless delta. This
way we fix the gtime value regression on machines not running nohz full.

The kernel config contains CONFIG_VIRT_CPU_ACCOUNTING_GEN=y and
CONFIG_NO_HZ_FULL_ALL=n and boot without nohz_full.

I ran and stop a busy loop in VM and see the gtime in host.
Dump the 43rd field which shows the gtime in every second:

	 # while :; do awk '{print $3" "$43}' /proc/3955/task/4014/stat; sleep 1; done
	S 4348
	R 7064566
	R 7064766
	R 7064967
	R 7065168
	S 4759
	S 4759

During running busy loop, it returns large value.

After applying this patch, we can see right gtime.

	 # while :; do awk '{print $3" "$43}' /proc/10913/task/10956/stat; sleep 1; done
	S 5338
	R 5365
	R 5465
	R 5566
	R 5666
	S 5726
	S 5726

Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul E . McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1447948054-28668-2-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-12-04 10:18:49 +01:00
..
bpf bpf, verifier: annotate verbose printer with __printf 2015-11-03 11:29:56 -05:00
configs kconfig: add xenconfig defconfig helper 2015-06-16 11:04:29 +01:00
debug
events Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-11-15 09:36:24 -08:00
gcov gcov: add support for GCC 5.1 2015-06-30 19:44:57 -07:00
irq Merge branches 'irq-urgent-for-linus' and 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-11-15 09:30:48 -08:00
livepatch livepatch: x86: fix relocation computation with kASLR 2015-11-11 17:36:04 +01:00
locking mm, page_alloc: distinguish between being unable to sleep, unwilling to sleep and avoiding waking kswapd 2015-11-06 17:50:42 -08:00
power mm, page_alloc: rename __GFP_WAIT to __GFP_RECLAIM 2015-11-06 17:50:42 -08:00
printk printk: prevent userland from spoofing kernel messages 2015-11-06 17:50:42 -08:00
rcu Merge branches 'doc.2015.10.06a', 'percpu-rwsem.2015.10.06a' and 'torture.2015.10.06a' into HEAD 2015-10-07 16:06:25 -07:00
sched sched/cputime: Fix invalid gtime in proc 2015-12-04 10:18:49 +01:00
time Merge branches 'irq-urgent-for-linus' and 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-11-15 09:30:48 -08:00
trace This contains three more clean up patches. 2015-11-12 16:22:54 -08:00
.gitignore certs: add .gitignore to stop git nagging about x509_certificate_list 2015-10-21 15:18:35 +01:00
acct.c acct: check FMODE_CAN_WRITE 2015-04-11 22:27:55 -04:00
async.c
audit_fsnotify.c audit: clean simple fsnotify implementation 2015-08-06 16:14:53 -04:00
audit_tree.c audit: audit_tree_match can be boolean 2015-11-04 08:23:51 -05:00
audit_watch.c Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/audit 2015-09-08 13:34:59 -07:00
audit.c mm, page_alloc: distinguish between being unable to sleep, unwilling to sleep and avoiding waking kswapd 2015-11-06 17:50:42 -08:00
audit.h audit: audit_tree_match can be boolean 2015-11-04 08:23:51 -05:00
auditfilter.c audit: fix comment block whitespace 2015-11-04 08:23:51 -05:00
auditsc.c Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/audit 2015-09-08 13:34:59 -07:00
backtracetest.c
bounds.c
capability.c kernel: conditionally support non-root users, groups and capabilities 2015-04-15 16:35:22 -07:00
cgroup_freezer.c cgroup: allow a cgroup subsystem to reject a fork 2015-07-14 17:29:23 -04:00
cgroup_pids.c cgroup: add cgroup_subsys->free() method and use it to fix pids controller 2015-10-15 16:41:53 -04:00
cgroup.c mm, page_alloc: distinguish between being unable to sleep, unwilling to sleep and avoiding waking kswapd 2015-11-06 17:50:42 -08:00
compat.c compat: cleanup coding in compat_get_bitmap() and compat_put_bitmap() 2015-06-04 23:57:18 +02:00
configs.c
context_tracking.c context_tracking: avoid irq_save/irq_restore on guest entry and exit 2015-11-10 12:06:23 +01:00
cpu_pm.c kernel/cpu_pm: fix cpu_cluster_pm_exit comment 2015-09-03 02:42:20 +02:00
cpu.c Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-11-03 18:03:50 -08:00
cpuset.c Merge branch 'akpm' (patches from Andrew) 2015-11-05 23:10:54 -08:00
crash_dump.c
cred.c kernel/cred.c: remove unnecessary kdebug atomic reads 2015-09-10 13:29:01 -07:00
delayacct.c
dma.c
elfcore.c
exec_domain.c Remove rest of exec domains. 2015-04-12 21:03:31 +02:00
exit.c Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-11-03 18:03:50 -08:00
extable.c kernel/extable.c: remove duplicated include 2015-09-10 13:29:01 -07:00
fork.c Merge branch 'akpm' (patches from Andrew) 2015-11-05 23:10:54 -08:00
freezer.c
futex_compat.c
futex.c driver core update for 4.4-rc1 2015-11-04 21:50:37 -08:00
groups.c kernel: conditionally support non-root users, groups and capabilities 2015-04-15 16:35:22 -07:00
hung_task.c kernel/hung_task.c: change hung_task.c to use for_each_process_thread() 2015-04-15 16:35:22 -07:00
irq_work.c
jump_label.c locking/static_keys: Add selftest 2015-08-03 11:34:16 +02:00
kallsyms.c
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks locking/qrwlock: Rename QUEUE_RWLOCK to QUEUED_RWLOCKS 2015-05-12 09:46:00 +02:00
Kconfig.preempt
kexec_core.c kexec: use file name as the output message prefix 2015-11-06 17:50:42 -08:00
kexec_file.c kexec: use file name as the output message prefix 2015-11-06 17:50:42 -08:00
kexec_internal.h kexec: split kexec_file syscall code to kexec_file.c 2015-09-10 13:29:01 -07:00
kexec.c kexec: use file name as the output message prefix 2015-11-06 17:50:42 -08:00
kmod.c kmod: don't run async usermode helper as a child of kworker thread 2015-10-23 17:55:10 +09:00
kprobes.c perf/x86/hw_breakpoints: Disallow kernel breakpoints unless kprobe-safe 2015-08-04 10:16:54 +02:00
ksysfs.c kexec: split kexec_load syscall from kexec core code 2015-09-10 13:29:01 -07:00
kthread.c kernel/kthread.c:kthread_create_on_node(): clarify documentation 2015-09-04 16:54:41 -07:00
latencytop.c
Makefile sys_membarrier(): system-wide memory barrier (generic, x86) 2015-09-11 15:21:34 -07:00
membarrier.c sys_membarrier(): system-wide memory barrier (generic, x86) 2015-09-11 15:21:34 -07:00
memremap.c libnvdimm for 4.4: 2015-11-10 12:07:22 -08:00
module_signing.c KEYS: Merge the type-specific data with the payload data 2015-10-21 15:18:36 +01:00
module-internal.h
module.c module: Fix locking in symbol_put_addr() 2015-08-24 10:37:01 +09:30
notifier.c Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-09-01 08:40:25 -07:00
nsproxy.c
padata.c
panic.c kernel/panic.c: turn off locks debug before releasing console lock 2015-11-20 16:17:32 -08:00
params.c Nothing exciting, minor tweaks and cleanups. 2015-11-09 15:53:39 -08:00
pid_namespace.c
pid.c rcu: Rename rcu_lockdep_assert() to RCU_LOCKDEP_WARN() 2015-07-22 15:27:32 -07:00
profile.c mm: rename alloc_pages_exact_node() to __alloc_pages_node() 2015-09-08 15:35:28 -07:00
ptrace.c seccomp, ptrace: add support for dumping seccomp filters 2015-10-27 19:55:13 -07:00
range.c
reboot.c kexec: split kexec_load syscall from kexec core code 2015-09-10 13:29:01 -07:00
relay.c kernel/relay.c: use kvfree() in relay_free_page_array() 2015-06-30 19:44:59 -07:00
resource.c mm: enhance region_is_ram() to region_intersects() 2015-08-10 23:07:05 -04:00
seccomp.c seccomp, ptrace: add support for dumping seccomp filters 2015-10-27 19:55:13 -07:00
signal.c kernel/signal.c: unexport sigsuspend() 2015-11-20 16:17:32 -08:00
smp.c mm, page_alloc: distinguish between being unable to sleep, unwilling to sleep and avoiding waking kswapd 2015-11-06 17:50:42 -08:00
smpboot.c stop_machine: Kill smp_hotplug_thread->pre_unpark, introduce stop_machine_unpark() 2015-10-20 10:23:55 +02:00
smpboot.h
softirq.c
stacktrace.c
stop_machine.c sched: Move cpu_active() tests from stop_two_cpus() into migrate_swap_stop() 2015-10-20 10:25:56 +02:00
sys_ni.c mm: mlock: add new mlock system call 2015-11-05 19:34:48 -08:00
sys.c pidns: fix set/getpriority and ioprio_set/get in PRIO_USER mode 2015-11-06 17:50:42 -08:00
sysctl_binary.c
sysctl.c kernel/watchdog.c: add sysctl knob hardlockup_panic 2015-11-05 19:34:48 -08:00
task_work.c task_work: remove fifo ordering guarantee 2015-09-05 13:46:58 -07:00
taskstats.c
test_kprobes.c
torture.c torture: Consolidate cond_resched_rcu_qs() into stutter_wait() 2015-10-06 11:25:01 -07:00
tracepoint.c tracepoint: Give priority to probes of tracepoints 2015-10-25 21:33:54 -04:00
tsacct.c
uid16.c
up.c
user_namespace.c capabilities: ambient capabilities 2015-09-04 16:54:41 -07:00
user-return-notifier.c
user.c
utsname_sysctl.c
utsname.c
watchdog.c kernel/watchdog.c: fix race between proc_watchdog_thresh() and watchdog_timer_fn() 2015-11-05 19:34:48 -08:00
workqueue_internal.h
workqueue.c Merge branch 'for-4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq 2015-11-05 14:16:27 -08:00