Pull scheduler fixes from Ingo Molnar:
"Two smaller fixes - plus a context tracking tracing fix that is a bit
bigger"
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
tracing/context-tracking: Add preempt_schedule_context() for tracing
sched: Fix clear NOHZ_BALANCE_KICK
sched/x86: Construct all sibling maps if smt
Pull perf fixes from Ingo Molnar:
"Four fixes. The mmap ones are unfortunately larger than desired -
fuzzing uncovered bugs that needed perf context life time management
changes to fix properly"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86: Fix broken PEBS-LL support on SNB-EP/IVB-EP
perf: Fix mmap() accounting hole
perf: Fix perf mmap bugs
kprobes: Fix to free gone and unused optprobes
Pull cpu idle fixes from Thomas Gleixner:
- Add a missing irq enable. Fallout of the idle conversion
- Fix stackprotector wreckage caused by the idle conversion
* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
idle: Enable interrupts in the weak arch_cpu_idle() implementation
idle: Add the stack canary init to cpu_startup_entry()
Pull timer fixes from Thomas Gleixner:
- Fix inconstinant clock usage in virtual time accounting
- Fix a build error in KVM caused by the NOHZ work
- Remove a pointless timekeeping duty assignment which breaks NOHZ
- Use a proper notifier return value to avoid random behaviour
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
tick: Remove useless timekeeping duty attribution to broadcast source
nohz: Fix notifier return val that enforce timekeeping
kvm: Move guest entry/exit APIs to context_tracking
vtime: Use consistent clocks among nohz accounting
This patch simply moves all per-cpu variables into the new
single per-cpu "struct bp_cpuinfo".
To me this looks more logical and clean, but this can also
simplify the further potential changes. In particular, I do not
think this memory should be per-cpu, it is never used "locally".
After this change it is trivial to turn it into, say,
bootmem[nr_cpu_ids].
Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20130620155020.GA6350@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The enable/disable logic in toggle_bp_slot() is not symmetrical
and imho very confusing. "old_count" in toggle_bp_task_slot() is
actually new_count because this bp was already removed from the
list.
Change toggle_bp_slot() to always call list_add/list_del after
toggle_bp_task_slot(). This way old_idx is task_bp_pinned() and
this entry should be decremented, new_idx is +/-weight and we
need to increment this element. The code/logic looks obvious.
Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20130620155011.GA6330@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
trinity fuzzer triggered WARN_ONCE("Can't find any breakpoint
slot") in arch_install_hw_breakpoint() but the problem is not
arch-specific.
The problem is, task_bp_pinned(cpu) checks "cpu == iter->cpu"
but this doesn't account the "all cpus" events with iter->cpu <
0.
This means that, say, register_user_hw_breakpoint(tsk) can
happily create the arbitrary number > HBP_NUM of breakpoints
which can not be activated. toggle_bp_task_slot() is equally
wrong by the same reason and nr_task_bp_pinned[] can have
negative entries.
Simple test:
# perl -e 'sleep 1 while 1' &
# perf record -e mem:0x10,mem:0x10,mem:0x10,mem:0x10,mem:0x10 -p `pidof perl`
Before this patch this triggers the same problem/WARN_ON(),
after the patch it correctly fails with -ENOSPC.
Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20130620155006.GA6324@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We have two very conflicting state variable names in the
watchdog:
* watchdog_enabled: This one reflects the user interface. It's
set to 1 by default and can be overriden with boot options
or sysctl/procfs interface.
* watchdog_disabled: This is the internal toggle state that
tells if watchdog threads, timers and NMI events are currently
running or not. This state mostly depends on the user settings.
It's a convenient state latch.
Now we really need to find clearer names because those
are just too confusing to encourage deep review.
watchdog_enabled now becomes watchdog_user_enabled to reflect
its purpose as an interface.
watchdog_disabled becomes watchdog_running to suggest its
role as a pure internal state.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Anish Singh <anish198519851985@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Don Zickus <dzickus@redhat.com>
Add a traceoff_on_warning option in both the kernel command line as well
as a sysctl option. When set, any WARN*() function that is hit will cause
the tracing_on variable to be cleared, which disables writing to the
ring buffer.
This is useful especially when tracing a bug with function tracing. When
a warning is hit, the print caused by the warning can flood the trace with
the functions that producing the output for the warning. This can make the
resulting trace useless by either hiding where the bug happened, or worse,
by overflowing the buffer and losing the trace of the bug totally.
Acked-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
There are some cases when filtering on a set flag of a field of a tracepoint
is useful. But currently the only filtering commands for numbered fields
is ==, !=, <, <=, >, >=. This does not help when you just want to trace if
a specific flag is set. For example:
> # sudo trace-cmd record -e brcmfmac:brcmf_dbg -f 'level & 0x40000'
> disable all
> enable brcmfmac:brcmf_dbg
> path = /sys/kernel/debug/tracing/events/brcmfmac/brcmf_dbg/enable
> (level & 0x40000)
> ^
> parse_error: Invalid operator
>
When trying to trace brcmf_dbg when level has its 1 << 18 bit set, the
filter fails to perform.
By allowing a binary '&' operation, this gives the user the ability to
test a bit.
Note, a binary '|' is not added, as it doesn't make sense as fields must
be compared to constants (for now), and ORing a constant will always return
true.
Link: http://lkml.kernel.org/r/1371057385.9844.261.camel@gandalf.local.home
Suggested-by: Arend van Spriel <arend@broadcom.com>
Tested-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The user activation/deactivation of the watchdog through boot parameters
or systcl is currently implemented with a dance involving kthreads parking
and unparking methods: the threads are unconditionally registered on
boot and they park as soon as the user want the watchdog to be disabled.
This method involves a few noisy details to handle though: the watchdog
kthreads may be unparked anytime due to hotplug operations, after which
the watchdog internals have to decide to park again if it is user-disabled.
As a result the setup() and unpark() methods need to be able to request a
reparking. This is not currently supported in the kthread infrastructure
so this piece of the watchdog code only works halfway.
Besides, unparking/reparking the watchdog kthreads consume unnecessary
cputime on hotplug operations when those could be simply ignored in the
first place.
As suggested by Srivatsa, let's instead only register the watchdog
threads when they are needed. This way we don't need to think about
hotplug operations and we don't burden the CPU onlining when the watchdog
is simply disabled.
Suggested-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Anish Singh <anish198519851985@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Don Zickus <dzickus@redhat.com>
Pull RCU changes from Paul E. McKenney:
"The major changes for this series are:
1. Simplify RCU's grace-period and callback processing based on
the new numbering for callbacks. These were posted to LKML at
https://lkml.org/lkml/2013/5/20/330.
2. Documentation updates. These were posted to LKML at
https://lkml.org/lkml/2013/5/20/348.
3. Miscellaneous fixes, including converting a few remaining printk()
calls to pr_*(). These were posted to LKML at
https://lkml.org/lkml/2013/5/20/324.
4. SRCU-related changes and fixes. These were posted to LKML at
https://lkml.org/lkml/2013/5/20/425.
5. Removal of TINY_PREEMPT_RCU in favor of TREE_PREEMPT_RCU for
single-CPU low-latency systems. These were posted to LKML at
https://lkml.org/lkml/2013/5/20/427."
Signed-off-by: Ingo Molnar <mingo@kernel.org>
