xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity
Files
58bfea9532552d422bde7afa207e1a0f08dffa7d
android_kernel_xiaomi_sm8450/kernel
History
John Stultz 58bfea9532 timekeeping: Fix __ktime_get_fast_ns() regression 
In commit 27727df240 ("Avoid taking lock in NMI path with
CONFIG_DEBUG_TIMEKEEPING"), I changed the logic to open-code
the timekeeping_get_ns() function, but I forgot to include
the unit conversion from cycles to nanoseconds, breaking the
function's output, which impacts users like perf.

This results in bogus perf timestamps like:
 swapper     0 [000]   253.427536:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]   254.426573:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]   254.426687:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]   254.426800:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]   254.426905:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]   254.427022:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]   254.427127:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]   254.427239:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]   254.427346:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]   254.427463:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]   255.426572:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])

Instead of more reasonable expected timestamps like:
 swapper     0 [000]    39.953768:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]    40.064839:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]    40.175956:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]    40.287103:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]    40.398217:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]    40.509324:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]    40.620437:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]    40.731546:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]    40.842654:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]    40.953772:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]    41.064881:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])

Add the proper use of timekeeping_delta_to_ns() to convert
the cycle delta to nanoseconds as needed.

Thanks to Brendan and Alexei for finding this quickly after
the v4.8 release. Unfortunately the problematic commit has
landed in some -stable trees so they'll need this fix as
well.

Many apologies for this mistake. I'll be looking to add a
perf-clock sanity test to the kselftest timers tests soon.

Fixes: 27727df240 "timekeeping: Avoid taking lock in NMI path with CONFIG_DEBUG_TIMEKEEPING"
Reported-by: Brendan Gregg <bgregg@netflix.com>
Reported-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Tested-and-reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable <stable@vger.kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1475636148-26539-1-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-10-05 15:44:46 +02:00
..
bpf
bpf: fix bpf_skb_in_cgroup helper naming
2016-08-12 21:53:33 -07:00
configs
kconfig: tinyconfig: provide whole choice blocks to avoid warnings
2016-09-01 17:52:01 -07:00
debug
mm/init: Add 'rodata=off' boot cmdline parameter to disable read-only kernel mappings
2016-02-22 08:51:37 +01:00
events
Merge branch 'perf/urgent' into perf/core, to pick up fixes
2016-09-23 07:20:33 +02:00
gcov
gcov: add support for gcc version >= 6
2016-07-15 14:54:27 +09:00
irq
genirq: Make function __irq_do_set_handler() static
2016-09-25 16:46:52 -04:00
livepatch
modules: add ro_after_init support
2016-08-04 10:16:55 +09:30
locking
locking/lglock: Remove lglock implementation
2016-09-22 15:25:56 +02:00
power
PM / Hibernate: allow hibernation with PAGE_POISONING_ZERO
2016-09-13 02:35:27 +02:00
printk
printk/nmi: avoid direct printk()-s from __printk_nmi_flush()
2016-09-01 17:52:01 -07:00
rcu
Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2016-10-03 12:15:00 -07:00
sched
Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2016-10-03 16:13:28 -07:00
time
timekeeping: Fix __ktime_get_fast_ns() regression
2016-10-05 15:44:46 +02:00
trace
Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2016-10-03 16:13:28 -07:00
.gitignore
certs: add .gitignore to stop git nagging about x509_certificate_list
2015-10-21 15:18:35 +01:00
acct.c
…
async.c
async: export current_is_async()
2015-11-19 17:51:48 +01:00
audit_fsnotify.c
wrappers for ->i_mutex access
2016-01-22 18:04:28 -05:00
audit_tree.c
audit: cleanup prune_tree_thread
2016-04-04 09:46:47 -04:00
audit_watch.c
Merge branch 'stable-4.8' of git://git.infradead.org/users/pcmoore/audit
2016-09-01 15:55:56 -07:00
audit.c
Merge branch 'stable-4.8' of git://git.infradead.org/users/pcmoore/audit
2016-07-29 17:54:17 -07:00
audit.h
Merge branch 'stable-4.8' of git://git.infradead.org/users/pcmoore/audit
2016-07-29 17:54:17 -07:00
auditfilter.c
audit: add fields to exclude filter by reusing user filter
2016-06-27 11:01:00 -04:00
auditsc.c
Merge branch 'stable-4.8' of git://git.infradead.org/users/pcmoore/audit
2016-07-29 17:54:17 -07:00
backtracetest.c
…
bounds.c
…
capability.c
kernel: Add noaudit variant of ns_capable()
2016-06-06 20:16:18 +10:00
cgroup_freezer.c
cgroup: kill cgrp_ss_priv[CGROUP_CANFORK_COUNT] and friends
2015-12-03 10:24:08 -05:00
cgroup_pids.c
cgroup: Use lld instead of ld when printing pids controller events_limit
2016-06-21 15:03:36 -04:00
cgroup.c
Merge branch 'linus' into locking/core, to pick up fixes
2016-09-30 10:54:46 +02:00
compat.c
…
configs.c
…
context_tracking.c
context_tracking: Switch to new static_branch API
2015-11-24 09:56:43 +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 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2016-10-03 19:43:08 -07:00
cpuset.c
cpuset: fix non static symbol warning
2016-09-16 11:31:17 -04:00
crash_dump.c
…
cred.c
cred: Reject inodes with invalid ids in set_create_file_as()
2016-06-30 18:05:09 -05:00
delayacct.c
kmemcg: account certain kmem allocations to memcg
2016-01-14 16:00:49 -08:00
dma.c
…
elfcore.c
…
exec_domain.c
…
exit.c
sched/core: Optimize __schedule()
2016-09-22 14:53:45 +02:00
extable.c
kernel/extable.c: remove duplicated include
2015-09-10 13:29:01 -07:00
fork.c
fork: Optimize task creation by caching two thread stacks per CPU if CONFIG_VMAP_STACK=y
2016-09-16 09:18:54 +02:00
freezer.c
freezer, oom: check TIF_MEMDIE on the correct task
2016-07-28 16:07:41 -07:00
futex_compat.c
ptrace: use fsuid, fsgid, effective creds for fs access checks
2016-01-20 17:09:18 -08:00
futex.c
futex: Add some more function commentry
2016-09-05 17:20:18 +02:00
groups.c
…
hung_task.c
locking/hung_task: Show all locks
2016-08-24 12:16:13 +02:00
irq_work.c
treewide: Remove old email address
2015-11-23 09:44:58 +01:00
jump_label.c
Merge tag 'powerpc-4.8-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
2016-08-05 09:00:54 -04:00
kallsyms.c
kallsyms: add support for relative offsets in kallsyms address table
2016-03-15 16:55:16 -07:00
kcmp.c
ptrace: use fsuid, fsgid, effective creds for fs access checks
2016-01-20 17:09:18 -08:00
Kconfig.freezer
…
Kconfig.hz
…
Kconfig.locks
…
Kconfig.preempt
…
kcov.c
kernel/kcov: unproxify debugfs file's fops
2016-06-15 04:56:35 -07:00
kexec_core.c
kexec: add restriction on kexec_load() segment sizes
2016-08-02 19:35:31 -04:00
kexec_file.c
kexec: fix double-free when failing to relocate the purgatory
2016-09-01 17:52:01 -07:00
kexec_internal.h
kexec: move some memembers and definitions within the scope of CONFIG_KEXEC_FILE
2016-01-20 17:09:18 -08:00
kexec.c
kexec: allow architectures to override boot mapping
2016-08-02 19:35:27 -04:00
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: add a kexec_crash_loaded() function
2016-08-02 19:35:30 -04:00
kthread.c
kthread: Pin the stack via try_get_task_stack()/put_task_stack() in to_live_kthread() function
2016-09-16 09:18:53 +02:00
latencytop.c
sched/debug: Make schedstats a runtime tunable that is disabled by default
2016-02-09 11:54:23 +01:00
Makefile
ELF/MIPS build fix
2016-05-23 17:04:14 -07:00
membarrier.c
sys_membarrier(): system-wide memory barrier (generic, x86)
2015-09-11 15:21:34 -07:00
memremap.c
mm: fix cache mode of dax pmd mappings
2016-09-09 17:34:46 -07:00
module_signing.c
KEYS: Move the point of trust determination to __key_link()
2016-04-11 22:43:43 +01:00
module-internal.h
…
module.c
Merge tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux
2016-08-04 09:14:38 -04:00
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
cgroup: introduce cgroup namespaces
2016-02-16 13:04:58 -05:00
padata.c
padata: Convert to hotplug state machine
2016-09-19 21:44:30 +02:00
panic.c
kexec: use core_param for crash_kexec_post_notifiers boot option
2016-08-02 19:35:29 -04:00
params.c
Merge tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux
2015-11-09 15:53:39 -08:00
pid_namespace.c
…
pid.c
remove lots of IS_ERR_VALUE abuses
2016-05-27 15:26:11 -07:00
profile.c
profile: Convert to hotplug state machine
2016-07-15 10:41:42 +02:00
ptrace.c
tree-wide: replace config_enabled() with IS_ENABLED()
2016-08-04 08:50:07 -04:00
range.c
…
reboot.c
kexec: split kexec_load syscall from kexec core code
2015-09-10 13:29:01 -07:00
relay.c
relayfs: Convert to hotplug state machine
2016-09-06 18:30:20 +02:00
resource.c
/proc/iomem: only expose physical resource addresses to privileged users
2016-04-14 12:56:09 -07:00
seccomp.c
seccomp: Fix tracer exit notifications during fatal signals
2016-08-30 16:12:46 -07:00
signal.c
x86/signal: Add SA_{X32,IA32}_ABI sa_flags
2016-09-14 21:28:11 +02:00
smp.c
smp: Allocate smp_call_on_cpu() workqueue on stack too
2016-09-22 14:49:10 +02:00
smpboot.c
sched/core: Do not use smp_processor_id() with preempt enabled in smpboot_thread_fn()
2016-09-22 12:28:00 +02:00
smpboot.h
cpu/hotplug: Create hotplug threads
2016-03-01 20:36:56 +01:00
softirq.c
Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2016-10-03 19:43:08 -07:00
stacktrace.c
…
stop_machine.c
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2016-10-03 13:39:00 -07:00
sys_ni.c
vfs: add copy_file_range syscall and vfs helper
2015-12-01 14:00:53 -05:00
sys.c
prctl: make PR_SET_THP_DISABLE wait for mmap_sem killable
2016-05-23 17:04:14 -07:00
sysctl_binary.c
kernel/sysctl_binary.c: use generic UUID library
2016-05-20 17:58:30 -07:00
sysctl.c
sysctl: handle error writing UINT_MAX to u32 fields
2016-08-26 17:39:35 -07:00
task_work.c
task_work: use READ_ONCE/lockless_dereference, avoid pi_lock if !task_works
2016-08-02 19:35:02 -04:00
taskstats.c
taskstats: use the libnl API to align nlattr on 64-bit
2016-04-23 20:13:25 -04:00
test_kprobes.c
…
torture.c
torture: Convert torture_shutdown() to hrtimer
2016-08-22 10:01:49 -07:00
tracepoint.c
kernel/...: convert pr_warning to pr_warn
2016-03-22 15:36:02 -07:00
tsacct.c
time, acct: Drop irq save & restore from __acct_update_integrals()
2016-02-29 09:53:09 +01:00
uid16.c
…
up.c
smp: Add function to execute a function synchronously on a CPU
2016-09-05 13:52:39 +02:00
user_namespace.c
fs: Limit file caps to the user namespace of the super block
2016-06-24 10:40:31 -05:00
user-return-notifier.c
…
user.c
…
utsname_sysctl.c
…
utsname.c
…
watchdog.c
Revert "perf/x86/intel, watchdog: Switch NMI watchdog to ref cycles on x86"
2016-07-10 20:58:36 +02:00
workqueue_internal.h
sched/core: Get rid of 'cpu' argument in wq_worker_sleeping()
2016-03-02 10:28:47 -05:00
workqueue.c
Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2016-07-29 13:55:30 -07:00