forge/linux-uconsole
1
0
Fork 0
Code Issues 1 Pull requests Projects Releases Packages Wiki Activity Actions
linux-uconsole/kernel
History
Phil Auld c3edd427d5 sched/fair: Limit sched_cfs_period_timer() loop to avoid hard lockup 
[ Upstream commit 2e8e192263 ]

With extremely short cfs_period_us setting on a parent task group with a large
number of children the for loop in sched_cfs_period_timer() can run until the
watchdog fires. There is no guarantee that the call to hrtimer_forward_now()
will ever return 0.  The large number of children can make
do_sched_cfs_period_timer() take longer than the period.

 NMI watchdog: Watchdog detected hard LOCKUP on cpu 24
 RIP: 0010:tg_nop+0x0/0x10
  <IRQ>
  walk_tg_tree_from+0x29/0xb0
  unthrottle_cfs_rq+0xe0/0x1a0
  distribute_cfs_runtime+0xd3/0xf0
  sched_cfs_period_timer+0xcb/0x160
  ? sched_cfs_slack_timer+0xd0/0xd0
  __hrtimer_run_queues+0xfb/0x270
  hrtimer_interrupt+0x122/0x270
  smp_apic_timer_interrupt+0x6a/0x140
  apic_timer_interrupt+0xf/0x20
  </IRQ>

To prevent this we add protection to the loop that detects when the loop has run
too many times and scales the period and quota up, proportionally, so that the timer
can complete before then next period expires.  This preserves the relative runtime
quota while preventing the hard lockup.

A warning is issued reporting this state and the new values.

Signed-off-by: Phil Auld <pauld@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Cc: Anton Blanchard <anton@ozlabs.org>
Cc: Ben Segall <bsegall@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190319130005.25492-1-pauld@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-04-27 09:36:40 +02:00
..
bpf bpf: fix use after free in bpf_evict_inode 2019-04-20 09:16:05 +02:00
cgroup cgroup/pids: turn cgroup_subsys->free() into cgroup_subsys->release() to fix the accounting 2019-04-05 22:33:13 +02:00
configs kconfig: tinyconfig: remove stale stack protector fixups 2018-06-15 07:15:28 +09:00
debug kdb: Don't back trace on a cpu that didn't round up 2019-02-12 19:47:19 +01:00
dma dma-direct: do not include SME mask in the DMA supported check 2019-01-13 09:51:05 +01:00
events perf/core: Restore mmap record type correctly 2019-04-20 09:15:54 +02:00
gcov gcov: remove CONFIG_GCOV_FORMAT_AUTODETECT 2018-06-08 18:56:02 +09:00
irq genirq: Initialize request_mutex if CONFIG_SPARSE_IRQ=n 2019-04-17 08:38:52 +02:00
livepatch Merge branch 'for-4.19/upstream' into for-linus 2018-08-20 18:33:50 +02:00
locking locking/lockdep: Add debug_locks check in __lock_downgrade() 2019-03-27 14:14:43 +09:00
power Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input 2018-10-12 12:35:02 +02:00
printk printk: Fix panic caused by passing log_buf_len to command line 2018-11-13 11:08:48 -08:00
rcu kprobes: Prohibit probing on RCU debug routine 2019-04-05 22:33:08 +02:00
sched sched/fair: Limit sched_cfs_period_timer() loop to avoid hard lockup 2019-04-27 09:36:40 +02:00
time timers/sched_clock: Prevent generic sched_clock wrap caused by tick_freeze() 2019-04-27 09:36:38 +02:00
trace kprobes: Mark ftrace mcount handler functions nokprobe 2019-04-27 09:36:37 +02:00
.gitignore
acct.c
async.c
audit.c audit: use ktime_get_coarse_real_ts64() for timestamps 2018-07-17 14:45:08 -04:00
audit.h
audit_fsnotify.c fsnotify: add fsnotify_add_inode_mark() wrappers 2018-05-18 14:58:22 +02:00
audit_tree.c \n 2018-08-17 09:41:28 -07:00
audit_watch.c audit: fix use-after-free in audit_add_watch 2018-07-18 11:43:36 -04:00
auditfilter.c audit: rename FILTER_TYPE to FILTER_EXCLUDE 2018-06-19 10:39:54 -04:00
auditsc.c audit/stable-4.18 PR 20180814 2018-08-15 10:46:54 -07:00
backtracetest.c
bounds.c kbuild: fix kernel/bounds.c 'W=1' warning 2018-11-13 11:08:47 -08:00
capability.c
compat.c time: Enable get/put_compat_itimerspec64 always 2018-06-24 14:39:47 +02:00
configs.c
context_tracking.c
cpu.c cpu/hotplug: Mute hotplug lockdep during init 2019-04-05 22:33:14 +02:00
cpu_pm.c
crash_core.c kernel/crash_core.c: print timestamp using time64_t 2018-08-22 10:52:47 -07:00
crash_dump.c
cred.c
delayacct.c delayacct: Use raw_spinlocks 2018-04-27 14:34:51 +02:00
dma.c proc: introduce proc_create_single{,_data} 2018-05-16 07:23:35 +02:00
elfcore.c
exec_domain.c proc: introduce proc_create_single{,_data} 2018-05-16 07:23:35 +02:00
exit.c cgroup/pids: turn cgroup_subsys->free() into cgroup_subsys->release() to fix the accounting 2019-04-05 22:33:13 +02:00
extable.c
fail_function.c bpf/error-inject/kprobes: Clear current_kprobe and enable preempt in kprobe 2018-06-21 12:33:19 +02:00
fork.c fork: record start_time late 2019-01-13 09:51:04 +01:00
freezer.c PM / reboot: Eliminate race between reboot and suspend 2018-08-06 12:35:20 +02:00
futex.c futex: Ensure that futex address is aligned in handle_futex_death() 2019-03-27 14:14:40 +09:00
futex_compat.c
groups.c
hung_task.c kernel: hung_task.c: disable on suspend 2019-04-20 09:16:02 +02:00
iomem.c memremap: split devm_memremap_pages() and memremap() infrastructure 2018-05-15 23:08:33 -07:00
irq_work.c
jump_label.c jump_label: Fix typo in warning message 2018-09-10 10:15:48 +02:00
kallsyms.c kallsyms, x86: Export addresses of PTI entry trampolines 2018-08-14 19:12:29 -03:00
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt kconfig: include kernel/Kconfig.preempt from init/Kconfig 2018-08-02 08:06:54 +09:00
kcov.c kernel/kcov.c: mark write_comp_data() as notrace 2019-02-12 19:47:20 +01:00
kexec.c kexec: add call to LSM hook in original kexec_load syscall 2018-07-16 12:31:57 -07:00
kexec_core.c kexec: yield to scheduler when loading kimage segments 2018-06-15 07:55:24 +09:00
kexec_file.c treewide: Use array_size() in vzalloc() 2018-06-12 16:19:22 -07:00
kexec_internal.h
kmod.c
kprobes.c kprobes: Fix error check when reusing optimized probes 2019-04-27 09:36:37 +02:00
ksysfs.c
kthread.c Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-08-13 11:25:07 -07:00
latencytop.c
Makefile kbuild: move bin2c back to scripts/ from scripts/basic/ 2018-07-18 01:18:05 +09:00
memremap.c mm, devm_memremap_pages: add MEMORY_DEVICE_PRIVATE support 2019-01-13 09:51:04 +01:00
module-internal.h modsign: log module name in the event of an error 2018-07-02 11:36:17 +02:00
module.c kobject: return error code if writing /sys/.../uevent fails 2019-02-12 19:47:06 +01:00
module_signing.c modsign: log module name in the event of an error 2018-07-02 11:36:17 +02:00
notifier.c
nsproxy.c
padata.c
panic.c panic: avoid deadlocks in re-entrant console drivers 2018-12-29 13:37:57 +01:00
params.c
pid.c Fix failure path in alloc_pid() 2019-01-13 09:51:06 +01:00
pid_namespace.c
profile.c
ptrace.c ptrace: Remove unused ptrace_may_access_sched() and MODE_IBRS 2018-12-05 19:32:03 +01:00
range.c
reboot.c PM / reboot: Eliminate race between reboot and suspend 2018-08-06 12:35:20 +02:00
relay.c relay: check return of create_buf_file() properly 2019-03-13 14:02:35 -07:00
resource.c libnvdimm for 4.18 2018-06-08 17:21:52 -07:00
rseq.c rseq: uapi: Declare rseq_cs field as union, update includes 2018-07-10 22:18:52 +02:00
seccomp.c audit/stable-4.18 PR 20180605 2018-06-06 16:34:00 -07:00
signal.c signal: Restore the stop PTRACE_EVENT_EXIT 2019-02-20 10:25:48 +01:00
smp.c cpu/hotplug: Fix "SMT disabled by BIOS" detection for KVM 2019-02-12 19:47:25 +01:00
smpboot.c smpboot: Remove cpumask from the API 2018-07-03 09:20:44 +02:00
smpboot.h
softirq.c nohz: Fix missing tick reprogram when interrupting an inline softirq 2018-08-03 15:52:10 +02:00
stacktrace.c
stop_machine.c Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-08-13 11:25:07 -07:00
sys.c kernel/sys.c: remove duplicated include 2018-09-20 22:01:11 +02:00
sys_ni.c Merge branch 'core-rseq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-06-10 10:17:09 -07:00
sysctl.c sysctl: handle overflow for file-max 2019-04-05 22:32:57 +02:00
sysctl_binary.c
task_work.c
taskstats.c
test_kprobes.c kprobes: Remove jprobe API implementation 2018-06-21 12:33:05 +02:00
torture.c torture: Keep old-school dmesg format 2018-06-25 11:30:10 -07:00
tracepoint.c tracepoint: Fix tracepoint array element size mismatch 2018-10-17 15:35:29 -04:00
tsacct.c
ucount.c
uid16.c
uid16.h
umh.c umh: fix race condition 2018-06-07 16:56:28 -04:00
up.c
user-return-notifier.c
user.c userns: use irqsave variant of refcount_dec_and_lock() 2018-08-22 10:52:47 -07:00
user_namespace.c userns: also map extents in the reverse map to kernel IDs 2018-11-13 11:09:00 -08:00
utsname.c
utsname_sysctl.c sys: don't hold uts_sem while accessing userspace memory 2018-08-11 02:05:53 -05:00
watchdog.c watchdog: Respect watchdog cpumask on CPU hotplug 2019-04-03 06:26:29 +02:00
watchdog_hld.c watchdog: Mark watchdog touch functions as notrace 2018-08-30 12:56:40 +02:00
workqueue.c watchdog: Mark watchdog touch functions as notrace 2018-08-30 12:56:40 +02:00
workqueue_internal.h workqueue: Set worker->desc to workqueue name by default 2018-05-18 08:47:13 -07:00