Andi Kleen 2c95afc1e8 perf/x86/intel, watchdog: Switch NMI watchdog to ref cycles on x86 ... The NMI watchdog uses either the fixed cycles or a generic cycles counter. This causes a lot of conflicts with users of the PMU who want to run a full group including the cycles fixed counter, for example the --topdown support recently added to perf stat. The code needs to fall back to not use groups, which can cause measurement inaccuracy due to multiplexing errors. This patch switches the NMI watchdog to use reference cycles on Intel systems. This is actually more accurate than cycles, because cycles can tick faster than the measured CPU Frequency due to Turbo mode. The ref cycles always tick at their frequency, or slower when the system is idling. That means the NMI watchdog can never expire too early, unlike with cycles. The reference cycles tick roughly at the frequency of the TSC, so the same period computation can be used. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: acme@kernel.org Cc: jolsa@kernel.org Link: http://lkml.kernel.org/r/1465478079-19993-1-git-send-email-andi@firstfloor.org Signed-off-by: Ingo Molnar <mingo@kernel.org>		2016-06-14 11:16:59 +02:00
..
bpf	Merge branch 'linus' into perf/core, to refresh the branch	2016-06-08 09:26:46 +02:00
configs	…
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 'linus' into perf/core, to pick up fixes before merging new changes	2016-06-14 11:14:34 +02:00
gcov	gcov: disable for COMPILE_TEST	2016-05-10 17:12:49 +02:00
irq	irqchip updates for 4.7-rc1:	2016-06-03 15:05:51 +02:00
livepatch	Merge branches 'for-4.7/core', 'for-4.7/livepatching-doc' and 'for-4.7/livepatching-ppc64' into for-linus	2016-05-17 12:06:35 +02:00
locking	locking/qspinlock: Fix spin_unlock_wait() some more	2016-06-08 14:29:08 +02:00
power	PM / Hibernate: Call flush_icache_range() on pages restored in-place	2016-04-28 13:35:48 +01:00
printk	printk/nmi: flush NMI messages on the system panic	2016-05-20 17:58:30 -07:00
rcu	debugobjects: insulate non-fixup logic related to static obj from fixup callbacks	2016-05-19 19:12:14 -07:00
sched	Merge branch 'stacking-fixes' (vfs stacking fixes from Jann)	2016-06-10 12:10:02 -07:00
time	timer: Export destroy_hrtimer_on_stack()	2016-05-31 11:44:08 -07:00
trace	bpf, trace: use READ_ONCE for retrieving file ptr	2016-06-07 14:48:03 -07:00
.gitignore	…
Kconfig.freezer	…
Kconfig.hz	…
Kconfig.locks	…
Kconfig.preempt	…
Makefile	ELF/MIPS build fix	2016-05-23 17:04:14 -07:00
acct.c	…
async.c	…
audit.c	Merge branch 'stable-4.7' of git://git.infradead.org/users/pcmoore/audit	2016-05-18 18:46:55 -07:00
audit.h	…
audit_fsnotify.c	…
audit_tree.c	audit: cleanup prune_tree_thread	2016-04-04 09:46:47 -04:00
audit_watch.c	don't bother with ->d_inode->i_sb - it's always equal to ->d_sb	2016-04-10 17:11:51 -04:00
auditfilter.c	…
auditsc.c	Merge branch 'stable-4.7' of git://git.infradead.org/users/pcmoore/audit	2016-05-18 18:46:55 -07:00
backtracetest.c	…
bounds.c	…
capability.c	…
cgroup.c	cgroup: fix compile warning	2016-05-12 11:05:27 -04:00
cgroup_freezer.c	…
cgroup_pids.c	…
compat.c	…
configs.c	…
context_tracking.c	…
cpu.c	sched/hotplug: Make activate() the last hotplug step	2016-05-06 14:58:25 +02:00
cpu_pm.c	…
cpuset.c	cpuset: use static key better and convert to new API	2016-05-19 19:12:14 -07:00
crash_dump.c	…
cred.c	…
delayacct.c	…
dma.c	…
elfcore.c	…
exec_domain.c	…
exit.c	wait: allow sys_waitid() to accept __WNOTHREAD/__WCLONE/__WALL	2016-05-23 17:04:14 -07:00
extable.c	…
fork.c	mm: oom_reaper: remove some bloat	2016-05-26 15:35:44 -07:00
freezer.c	…
futex.c	futex: Calculate the futex key based on a tail page for file-based futexes	2016-06-08 19:23:54 +02:00
futex_compat.c	…
groups.c	…
hung_task.c	kernel/hung_task.c: use timeout diff when timeout is updated	2016-03-22 15:36:02 -07:00
irq_work.c	…
jump_label.c	…
kallsyms.c	kallsyms: add support for relative offsets in kallsyms address table	2016-03-15 16:55:16 -07:00
kcmp.c	…
kcov.c	kcov: don't profile branches in kcov	2016-04-28 19:34:04 -07:00
kexec.c	s390/kexec: consolidate crash_map/unmap_reserved_pages() and arch_kexec_protect(unprotect)_crashkres()	2016-05-23 17:04:14 -07:00
kexec_core.c	s390/kexec: consolidate crash_map/unmap_reserved_pages() and arch_kexec_protect(unprotect)_crashkres()	2016-05-23 17:04:14 -07:00
kexec_file.c	kexec: introduce a protection mechanism for the crashkernel reserved memory	2016-05-23 17:04:14 -07:00
kexec_internal.h	…
kmod.c	…
kprobes.c	…
ksysfs.c	…
kthread.c	…
latencytop.c	…
membarrier.c	…
memremap.c	memremap: add arch specific hook for MEMREMAP_WB mappings	2016-04-04 10:26:41 +02:00
module-internal.h	…
module.c	module: preserve Elf information for livepatch modules	2016-04-01 15:00:10 +02:00
module_signing.c	KEYS: Move the point of trust determination to __key_link()	2016-04-11 22:43:43 +01:00
notifier.c	…
nsproxy.c	…
padata.c	kernel/padata.c: hide unused functions	2016-05-19 19:12:14 -07:00
panic.c	printk/nmi: flush NMI messages on the system panic	2016-05-20 17:58:30 -07:00
params.c	…
pid.c	remove lots of IS_ERR_VALUE abuses	2016-05-27 15:26:11 -07:00
pid_namespace.c	…
profile.c	profile: hide unused functions when !CONFIG_PROC_FS	2016-03-22 15:36:02 -07:00
ptrace.c	ptrace: change __ptrace_unlink() to clear ->ptrace under ->siglock	2016-03-22 15:36:02 -07:00
range.c	…
reboot.c	…
relay.c	kernel/relay.c: fix potential memory leak	2016-06-09 14:23:11 -07:00
resource.c	/proc/iomem: only expose physical resource addresses to privileged users	2016-04-14 12:56:09 -07:00
seccomp.c	Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus	2016-05-19 10:02:26 -07:00
signal.c	kernel/signal.c: convert printk(KERN_<LEVEL> ...) to pr_<level>(...)	2016-05-23 17:04:14 -07:00
smp.c	Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2016-03-15 13:50:29 -07:00
smpboot.c	cpu/hotplug: Unpark smpboot threads from the state machine	2016-03-01 20:36:56 +01:00
smpboot.h	cpu/hotplug: Create hotplug threads	2016-03-01 20:36:56 +01:00
softirq.c	arch, ftrace: for KASAN put hard/soft IRQ entries into separate sections	2016-03-25 16:37:42 -07:00
stacktrace.c	…
stop_machine.c	…
sys.c	prctl: make PR_SET_THP_DISABLE wait for mmap_sem killable	2016-05-23 17:04:14 -07:00
sys_ni.c	…
sysctl.c	Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2016-05-25 17:05:40 -07:00
sysctl_binary.c	kernel/sysctl_binary.c: use generic UUID library	2016-05-20 17:58:30 -07:00
task_work.c	…
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	rcutorture: Dump trace buffer upon shutdown	2016-04-21 13:47:04 -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	…
user-return-notifier.c	…
user.c	…
user_namespace.c	…
utsname.c	…
utsname_sysctl.c	…
watchdog.c	perf/x86/intel, watchdog: Switch NMI watchdog to ref cycles on x86	2016-06-14 11:16:59 +02:00
workqueue.c	debugobjects: insulate non-fixup logic related to static obj from fixup callbacks	2016-05-19 19:12:14 -07:00
workqueue_internal.h	sched/core: Get rid of 'cpu' argument in wq_worker_sleeping()	2016-03-02 10:28:47 -05:00