This patch replaces NR_CPUS with nr_cpu_ids as NR_CPUS should
consider cpumask_var_t.
Signed-off-by: Himangi Saraogi <himangi774@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
This patch adds event tracing to dyntick_save_progress_counter() in the case
where it returns 1. I used the tracepoint string "dti" because this function
returns 1 in case the CPU is in dynticks idle mode.
Signed-off-by: Andreea-Cristina Bernat <bernat.ada@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Some of the accesses to the rcu_state structure's ->jiffies_stall
field are unprotected. This patch protects them with ACCESS_ONCE().
The following coccinelle script was used to acheive this:
/* coccinelle script to protect uses of ->jiffies_stall with ACCESS_ONCE() */
@@
identifier a;
@@
(
ACCESS_ONCE(a->jiffies_stall)
|
- a->jiffies_stall
+ ACCESS_ONCE(a->jiffies_stall)
)
Signed-off-by: Himangi Saraogi <himangi774@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
The rcu_start_gp_advanced() function currently uses irq_work_queue()
to defer wakeups of the RCU grace-period kthread. This deferring
is necessary to avoid RCU-scheduler deadlocks involving the rcu_node
structure's lock, meaning that RCU cannot call any of the scheduler's
wake-up functions while holding one of these locks.
Unfortunately, the second and subsequent calls to irq_work_queue() are
ignored, and the first call will be ignored (aside from queuing the work
item) if the scheduler-clock tick is turned off. This is OK for many
uses, especially those where irq_work_queue() is called from an interrupt
or softirq handler, because in those cases the scheduler-clock-tick state
will be re-evaluated, which will turn the scheduler-clock tick back on.
On the next tick, any deferred work will then be processed.
However, this strategy does not always work for RCU, which can be invoked
at process level from idle CPUs. In this case, the tick might never
be turned back on, indefinitely defering a grace-period start request.
Note that the RCU CPU stall detector cannot see this condition, because
there is no RCU grace period in progress. Therefore, we can (and do!)
see long tens-of-seconds stalls in grace-period handling. In theory,
we could see a full grace-period hang, but rcutorture testing to date
has seen only the tens-of-seconds stalls. Event tracing demonstrates
that irq_work_queue() is being called repeatedly to no effect during
these stalls: The "newreq" event appears repeatedly from a task that is
not one of the grace-period kthreads.
In theory, irq_work_queue() might be fixed to avoid this sort of issue,
but RCU's requirements are unusual and it is quite straightforward to pass
wake-up responsibility up through RCU's call chain, so that the wakeup
happens when the offending locks are released.
This commit therefore makes this change. The rcu_start_gp_advanced(),
rcu_start_future_gp(), rcu_accelerate_cbs(), rcu_advance_cbs(),
__note_gp_changes(), and rcu_start_gp() functions now return a boolean
which indicates when a wake-up is needed. A new rcu_gp_kthread_wake()
does the wakeup when it is necessary and safe to do so: No self-wakes,
no wake-ups if the ->gp_flags field indicates there is no need (as in
someone else did the wake-up before we got around to it), and no wake-ups
before the grace-period kthread has been created.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Some of the uses of the rcu_state structure's ->jiffies_stall field
do not use ACCESS_ONCE(), despite there being unprotected accesses.
This commit therefore uses the ACCESS_ONCE() macro to protect this field.
Signed-off-by: Iulia Manda <iulia.manda21@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
The ->preemptible field in rcu_data is only initialized in the function
rcu_init_percpu_data(), and never used. This commit therefore removes
this field.
Signed-off-by: Iulia Manda <iulia.manda21@gmail.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
In the old days, the only source of requests for future grace periods
was NOCB CPUs. This has changed: CPUs routinely post requests for
future grace periods in order to promote power efficiency and reduce
OS jitter with minimal impact on grace-period latency. This commit
therefore updates cpu_needs_another_gp() to invoke rcu_future_needs_gp()
instead of rcu_nocb_needs_gp(). The latter is no longer used, so is
now removed. This commit also adds tracing for the irq_work_queue()
wakeup case.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
The print_other_cpu_stall() and print_cpu_stall() functions print
grace-period numbers using an unsigned format, which means that the number
one less than zero is a very large number. This commit therefore causes
these numbers to be printed with a signed format in order to improve
readability of the RCU CPU stall-warning output.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Liu Ping Fan <kernelfans@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
A number of ->gp_flags accesses don't have ACCESS_ONCE(), but all of
the can race against other loads or stores. This commit therefore
applies ACCESS_ONCE() to the unprotected ->gp_flags accesses.
Reported-by: Alexey Roytman <alexey.roytman@oracle.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
loading a module and enabling function tracing at the same time.
He uncovered a race where the module when loaded will convert the
calls to mcount into nops, and expects the module's text to be RW.
But when function tracing is enabled, it will convert all kernel
text (core and module) from RO to RW to convert the nops to calls
to ftrace to record the function. After the convertion, it will
convert all the text back from RW to RO.
The issue is, it will also convert the module's text that is loading.
If it converts it to RO before ftrace does its conversion, it will
cause ftrace to fail and require a reboot to fix it again.
This patch moves the ftrace module update that converts calls to mcount
into nops to be done when the module state is still MODULE_STATE_UNFORMED.
This will ignore the module when the text is being converted from
RW back to RO.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1
iQEcBAABAgAGBQJTXuHsAAoJEKQekfcNnQGuT7cIAJQhwX2fpdFr5eHwx0CyFo5c
75V0xcRhJsGeXqfgekkRhCHYEfL7v4sl6D+Bj8qzLG/0QresF9jVSMUTTZqYFpFc
t7f3oDDtdCmfofD/uyS7YOQ3JhU5ijo+Drzq8qRYtWNJJ0WCqbddpevcUiW1Zbvr
LAT3lcb+2I5Y1Jnyfd920+0plAnoeOw1/BPuRVJINwh8zeyvWnmp3iq9fOPdhMQQ
VhCCg+C2ILBPrCPFdwC5pVrL4a/CjyNd+LqtFXjLS9sO8s5KyUGkqKkbHMlhZeot
uRWlZUSNZsh/jpP4X2b+dtYGQ4Rrnp253a594Kmrzm/MPdsAV62oDqOfN0tzm7w=
=K59a
-----END PGP SIGNATURE-----
Merge tag 'trace-fixes-v3.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull ftrace bugfix from Steven Rostedt:
"Takao Indoh reported that he was able to cause a ftrace bug while
loading a module and enabling function tracing at the same time.
He uncovered a race where the module when loaded will convert the
calls to mcount into nops, and expects the module's text to be RW.
But when function tracing is enabled, it will convert all kernel text
(core and module) from RO to RW to convert the nops to calls to ftrace
to record the function. After the convertion, it will convert all the
text back from RW to RO.
The issue is, it will also convert the module's text that is loading.
If it converts it to RO before ftrace does its conversion, it will
cause ftrace to fail and require a reboot to fix it again.
This patch moves the ftrace module update that converts calls to
mcount into nops to be done when the module state is still
MODULE_STATE_UNFORMED. This will ignore the module when the text is
being converted from RW back to RO"
* tag 'trace-fixes-v3.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
ftrace/module: Hardcode ftrace_module_init() call into load_module()
A race exists between module loading and enabling of function tracer.
CPU 1 CPU 2
----- -----
load_module()
module->state = MODULE_STATE_COMING
register_ftrace_function()
mutex_lock(&ftrace_lock);
ftrace_startup()
update_ftrace_function();
ftrace_arch_code_modify_prepare()
set_all_module_text_rw();
<enables-ftrace>
ftrace_arch_code_modify_post_process()
set_all_module_text_ro();
[ here all module text is set to RO,
including the module that is
loading!! ]
blocking_notifier_call_chain(MODULE_STATE_COMING);
ftrace_init_module()
[ tries to modify code, but it's RO, and fails!
ftrace_bug() is called]
When this race happens, ftrace_bug() will produces a nasty warning and
all of the function tracing features will be disabled until reboot.
The simple solution is to treate module load the same way the core
kernel is treated at boot. To hardcode the ftrace function modification
of converting calls to mcount into nops. This is done in init/main.c
there's no reason it could not be done in load_module(). This gives
a better control of the changes and doesn't tie the state of the
module to its notifiers as much. Ftrace is special, it needs to be
treated as such.
The reason this would work, is that the ftrace_module_init() would be
called while the module is in MODULE_STATE_UNFORMED, which is ignored
by the set_all_module_text_ro() call.
Link: http://lkml.kernel.org/r/1395637826-3312-1-git-send-email-indou.takao@jp.fujitsu.com
Reported-by: Takao Indoh <indou.takao@jp.fujitsu.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: stable@vger.kernel.org # 2.6.38+
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
do_div() needs 'u64' type, or it reports warning. And negative number
is meaningless for "speed", so change all signed to unsigned within
swsusp_show_speed().
The related warning (with allmodconfig for unicore32):
CC kernel/power/hibernate.o
kernel/power/hibernate.c: In function ‘swsusp_show_speed’:
kernel/power/hibernate.c:237: warning: comparison of distinct pointer types lacks a cast
Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
[rjw: Subject]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
On x86 the allocation of irq descriptors may allocate interrupts which
are in the range of the GSI interrupts. That's wrong as those
interrupts are hardwired and we don't have the irq domain translation
like PPC. So one of these interrupts can be hooked up later to one of
the devices which are hard wired to it and the io_apic init code for
that particular interrupt line happily reuses that descriptor with a
completely different configuration so hell breaks lose.
Inside x86 we allocate dynamic interrupts from above nr_gsi_irqs,
except for a few usage sites which have not yet blown up in our face
for whatever reason. But for drivers which need an irq range, like the
GPIO drivers, we have no limit in place and we don't want to expose
such a detail to a driver.
To cure this introduce a function which an architecture can implement
to impose a lower bound on the dynamic interrupt allocations.
Implement it for x86 and set the lower bound to nr_gsi_irqs, which is
the end of the hardwired interrupt space, so all dynamic allocations
happen above.
That not only allows the GPIO driver to work sanely, it also protects
the bogus callsites of create_irq_nr() in hpet, uv, irq_remapping and
htirq code. They need to be cleaned up as well, but that's a separate
issue.
Reported-by: Jin Yao <yao.jin@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Mathias Nyman <mathias.nyman@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: H. Peter Anvin <hpa@linux.intel.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Krogerus Heikki <heikki.krogerus@intel.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1404241617360.28206@ionos.tec.linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
We remove the waiting module removal in commit 3f2b9c9cdf (September
2013), but it turns out that modprobe in kmod (< version 16) was
asking for waiting module removal. No one noticed since modprobe would
check for 0 usage immediately before trying to remove the module, and
the race is unlikely.
However, it means that anyone running old (but not ancient) kmod
versions is hitting the printk designed to see if anyone was running
"rmmod -w". All reports so far have been false positives, so remove
the warning.
Fixes: 3f2b9c9cdf
Reported-by: Valerio Vanni <valerio.vanni@inwind.it>
Cc: Elliott, Robert (Server Storage) <Elliott@hp.com>
Cc: stable@kernel.org
Acked-by: Lucas De Marchi <lucas.de.marchi@gmail.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Pull irq fixes from Thomas Gleixner:
"A slighlty large fix for a subtle issue in the CPU hotplug code of
certain ARM SoCs, where the not yet online cpu needs to setup the cpu
local timer and needs to set the interrupt affinity to itself.
Setting interrupt affinity to a not online cpu is prohibited and
therefor the timer interrupt ends up on the wrong cpu, which leads to
nasty complications.
The SoC folks tried to hack around that in the SoC code in some more
than nasty ways. The proper solution is to have a way to enforce the
affinity setting to a not online cpu. The core patch to the genirq
code provides that facility and the follow up patches make use of it
in the GIC interrupt controller and the exynos timer driver.
The change to the core code has no implications to existing users,
except for the rename of the locked function and therefor the
necessary fixup in mips/cavium. Aside of that, no runtime impact is
possible, as none of the existing interrupt chips implements anything
which depends on the force argument of the irq_set_affinity()
callback"
* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
clocksource: Exynos_mct: Register clock event after request_irq()
clocksource: Exynos_mct: Use irq_force_affinity() in cpu bringup
irqchip: Gic: Support forced affinity setting
genirq: Allow forcing cpu affinity of interrupts
Support for uevent_helper, aka hotplug, is not required on many systems
these days but it can still be enabled via sysfs or sysctl.
Reported-by: Darren Shepherd <darren.s.shepherd@gmail.com>
Signed-off-by: Michael Marineau <mike@marineau.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It is possible by passing a netlink socket to a more privileged
executable and then to fool that executable into writing to the socket
data that happens to be valid netlink message to do something that
privileged executable did not intend to do.
To keep this from happening replace bare capable and ns_capable calls
with netlink_capable, netlink_net_calls and netlink_ns_capable calls.
Which act the same as the previous calls except they verify that the
opener of the socket had the desired permissions as well.
Reported-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When 'flags' argument to sched_{set,get}attr() syscalls were
added in:
6d35ab4809 ("sched: Add 'flags' argument to sched_{set,get}attr() syscalls")
no description for 'flags' was added. It causes the following warnings on "make htmldocs":
Warning(/kernel/sched/core.c:3645): No description found for parameter 'flags'
Warning(/kernel/sched/core.c:3789): No description found for parameter 'flags'
Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Cc: peterz@infradead.org
Link: http://lkml.kernel.org/r/1397753955-2914-1-git-send-email-standby24x7@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The "freeze" system sleep state introduced by commit 7e73c5ae6e
(PM: Introduce suspend state PM_SUSPEND_FREEZE) requires cpuidle
to be functional when freeze_enter() is executed to work correctly
(that is, to be able to save any more energy than runtime idle),
but that is impossible after commit 8651f97bd9 (PM / cpuidle:
System resume hang fix with cpuidle) which caused cpuidle to be
paused in dpm_suspend_noirq() and resumed in dpm_resume_noirq().
To avoid that problem, add cpuidle_resume() and cpuidle_pause()
to the beginning and the end of freeze_enter(), respectively.
Reported-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Pull more networking fixes from David Miller:
1) Fix mlx4_en_netpoll implementation, it needs to schedule a NAPI
context, not synchronize it. From Chris Mason.
2) Ipv4 flow input interface should never be zero, it should be
LOOPBACK_IFINDEX instead. From Cong Wang and Julian Anastasov.
3) Properly configure MAC to PHY connection in mvneta devices, from
Thomas Petazzoni.
4) sys_recv should use SYSCALL_DEFINE. From Jan Glauber.
5) Tunnel driver ioctls do not use the correct namespace, fix from
Nicolas Dichtel.
6) Fix memory leak on seccomp filter attach, from Kees Cook.
7) Fix lockdep warning for nested vlans, from Ding Tianhong.
8) Crashes can happen in SCTP due to how the auth_enable value is
managed, fix from Vlad Yasevich.
9) Wireless fixes from John W Linville and co.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (45 commits)
net: sctp: cache auth_enable per endpoint
tg3: update rx_jumbo_pending ring param only when jumbo frames are enabled
vlan: Fix lockdep warning when vlan dev handle notification
seccomp: fix memory leak on filter attach
isdn: icn: buffer overflow in icn_command()
ip6_tunnel: use the right netns in ioctl handler
sit: use the right netns in ioctl handler
ip_tunnel: use the right netns in ioctl handler
net: use SYSCALL_DEFINEx for sys_recv
net: mdio-gpio: Add support for separate MDI and MDO gpio pins
net: mdio-gpio: Add support for active low gpio pins
net: mdio-gpio: Use devm_ functions where possible
ipv4, route: pass 0 instead of LOOPBACK_IFINDEX to fib_validate_source()
ipv4, fib: pass LOOPBACK_IFINDEX instead of 0 to flowi4_iif
mlx4_en: don't use napi_synchronize inside mlx4_en_netpoll
net: mvneta: properly configure the MAC <-> PHY connection in all situations
net: phy: add minimal support for QSGMII PHY
sfc:On MCDI timeout, issue an FLR (and mark MCDI to fail-fast)
mwifiex: fix hung task on command timeout
mwifiex: process event before command response
...
Fix:
BUG: using __this_cpu_write() in preemptible [00000000] code: systemd-udevd/497
caller is __this_cpu_preempt_check+0x13/0x20
CPU: 3 PID: 497 Comm: systemd-udevd Tainted: G W 3.15.0-rc1 #9
Hardware name: Hewlett-Packard HP EliteBook 8470p/179B, BIOS 68ICF Ver. F.02 04/27/2012
Call Trace:
check_preemption_disabled+0xe1/0xf0
__this_cpu_preempt_check+0x13/0x20
touch_nmi_watchdog+0x28/0x40
Reported-by: Luis Henriques <luis.henriques@canonical.com>
Tested-by: Luis Henriques <luis.henriques@canonical.com>
Cc: Eric Piel <eric.piel@tremplin-utc.net>
Cc: Robert Moore <robert.moore@intel.com>
Cc: Lv Zheng <lv.zheng@intel.com>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The first is to remove a duplication of creating debugfs files that
already exist and causes an error report to be printed due to the
failure of the second creation.
The second is a memory leak fix that was introduced in 3.14.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1
iQEcBAABAgAGBQJTUGZwAAoJEKQekfcNnQGu7W8IAIAMBVfrWdP6cmGle4tGfhVE
sHcwqTH+07oANQJ3eFwFs5wBMb08s3hXwUHUxXcpjyq2Bs+AHr0vSL/nqCG4k8Ap
2T4ntL7esC1BWKw2lVVVYD12FiL7grUXVlx/q0WE2NuhCzWzNRTyb8sKrPoCRUEB
3o5rAt9+45PKUb2k/eqGBGhK8b4XDz2Wtk5Gj6YB3xttse/yjjcuw0gWMHN1JWfm
eRuQUUBDDGUGkfF98k1aLrjPZooT3LIAV8L8md5C3ebEcXSC/h86hTYCGXv3oBDO
8sxcT0zoQcLuFhjkYLL1J1lBW6gxaVh052jYmQwMppQMos+WID2un2E92Ccg49E=
=BwLF
-----END PGP SIGNATURE-----
Merge tag 'trace-fixes-v3.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt:
"This contains two fixes.
The first is to remove a duplication of creating debugfs files that
already exist and causes an error report to be printed due to the
failure of the second creation.
The second is a memory leak fix that was introduced in 3.14"
* tag 'trace-fixes-v3.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing/uprobes: Fix uprobe_cpu_buffer memory leak
tracing: Do not try to recreated toplevel set_ftrace_* files
There is a race condition between rescuer_thread() and
pwq_unbound_release_workfn().
Even after a pwq is scheduled for rescue, the associated work items
may be consumed by any worker. If all of them are consumed before the
rescuer gets to them and the pwq's base ref was put due to attribute
change, the pwq may be released while still being linked on
@wq->maydays list making the rescuer dereference already freed pwq
later.
Make send_mayday() pin the target pwq until the rescuer is done with
it.
tj: Updated comment and patch description.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org # v3.10+
After a @pwq is scheduled for emergency execution, other workers may
consume the affectd work items before the rescuer gets to them. This
means that a workqueue many have pwqs queued on @wq->maydays list
while not having any work item pending or in-flight. If
destroy_workqueue() executes in such condition, the rescuer may exit
without emptying @wq->maydays.
This currently doesn't cause any actual harm. destroy_workqueue() can
safely destroy all the involved data structures whether @wq->maydays
is populated or not as nobody access the list once the rescuer exits.
However, this is nasty and makes future development difficult. Let's
update rescuer_thread() so that it empties @wq->maydays after seeing
should_stop to guarantee that the list is empty on rescuer exit.
tj: Updated comment and patch description.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org # v3.10+
This patch adds support for building PMU driver as module. It exports
the functions perf_pmu_{register,unregister}() and adds reference tracking
for the PMU driver module.
When the PMU driver is built as a module, each active event of the PMU
holds a reference to the driver module.
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1395133004-23205-1-git-send-email-zheng.z.yan@intel.com
Cc: eranian@google.com
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This reverts commit 4c6c4e38c4 ("sched/core: Fix endless loop in
pick_next_task()"), which is not necessary after ("sched/rt: Substract number
of tasks of throttled queues from rq->nr_running").
Signed-off-by: Kirill Tkhai <tkhai@yandex.ru>
Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
[conflict resolution with stop task checking patch]
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1394835307.18748.34.camel@HP-250-G1-Notebook-PC
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Now rq->rt becomes to be able to be in dequeued or enqueued state.
We add new member rt_rq->rt_queued, which is used to indicate this.
The member is used only for top queue rq->rt_rq.
The goal is to fit generic scheme which is used in deadline and
fair classes, i.e. throttled rt_rq's rt_nr_running is beeing
substracted from rq->nr_running.
Signed-off-by: Kirill Tkhai <tkhai@yandex.ru>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1394835300.18748.33.camel@HP-250-G1-Notebook-PC
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
{inc,dec}_rt_tasks() used to count entities which are directly queued
on the rt_rq. If an entity was not a task (i.e., it is some queue), its
children were not counted.
There is no problem here, but now we want to count number of all tasks
which are actually queued under the rt_rq in all the hierarchy (except
throttled rt queues).
Empty queues are not able to be queued and all of the places, which
use ->rt_nr_running, just compare it with zero, so we do not break
anything here.
Signed-off-by: Kirill Tkhai <tkhai@yandex.ru>
Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1394835289.18748.31.camel@HP-250-G1-Notebook-PC
Cc: linux-kernel@vger.kernel.org
[ Twiddled the changelog. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Just switched pinned task is not able to be pushed. If the rq had had
several RT tasks before they have already been considered as candidates
to be pushed (or pulled).
Signed-off-by: Kirill V Tkhai <tkhai@yandex.ru>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140312061833.3a43aa64@gandalf.local.home
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Mike reported that, while unlikely, its entirely possible for
scale_rt_power() to see the time go backwards. This yields rather
'interesting' results.
So like all other sites that deal with clocks; make this one ignore
backward clock movement too.
Reported-by: Mike Galbraith <bitbucket@online.de>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140227094035.GZ9987@twins.programming.kicks-ass.net
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Since the smp_mb__{before,after}*() ops are fundamentally dependent on
how an arch can implement atomics it doesn't make sense to have 3
variants of them. They must all be the same.
Furthermore, the 3 variants suggest they're only valid for those 3
atomic ops, while we have many more where they could be applied.
So move away from
smp_mb__{before,after}_{atomic,clear}_{dec,inc,bit}() and reduce the
interface to just the two: smp_mb__{before,after}_atomic().
This patch prepares the way by introducing default implementations in
asm-generic/barrier.h that default to a full barrier and providing
__deprecated inlines for the previous 6 barriers if they're not
provided by the arch.
This should allow for a mostly painless transition (lots of deprecated
warns in the interim).
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/n/tip-wr59327qdyi9mbzn6x937s4e@git.kernel.org
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "Chen, Gong" <gong.chen@linux.intel.com>
Cc: John Sullivan <jsrhbz@kanargh.force9.co.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mauro Carvalho Chehab <m.chehab@samsung.com>
Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull timer fixes from Thomas Gleixner:
"Viresh unearthed the following three hickups in the timer/timekeeping
code:
- Negated check for the result of a clock event selection
- A missing early exit in the jiffies update path which causes
update_wall_time to be called for nothing causing lock contention
and wasted cycles in the timer interrupt
- Checking a variable in the NOHZ code enable code for true which can
only be set by that very code after the check succeeds. That
results in a rock solid runtime disablement of that feature"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
tick-sched: Check tick_nohz_enabled in tick_nohz_switch_to_nohz()
tick-sched: Don't call update_wall_time() when delta is lesser than tick_period
tick-common: Fix wrong check in tick_check_replacement()
The current implementation of irq_set_affinity() refuses rightfully to
route an interrupt to an offline cpu.
But there is a special case, where this is actually desired. Some of
the ARM SoCs have per cpu timers which require setting the affinity
during cpu startup where the cpu is not yet in the online mask.
If we can't do that, then the local timer interrupt for the about to
become online cpu is routed to some random online cpu.
The developers of the affected machines tried to work around that
issue, but that results in a massive mess in that timer code.
We have a yet unused argument in the set_affinity callbacks of the irq
chips, which I added back then for a similar reason. It was never
required so it got not used. But I'm happy that I never removed it.
That allows us to implement a sane handling of the above scenario. So
the affected SoC drivers can add the required force handling to their
interrupt chip, switch the timer code to irq_force_affinity() and
things just work.
This does not affect any existing user of irq_set_affinity().
Tagged for stable to allow a simple fix of the affected SoC clock
event drivers.
Reported-and-tested-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Tomasz Figa <t.figa@samsung.com>,
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>,
Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: linux-arm-kernel@lists.infradead.org,
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20140416143315.717251504@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Currently the error from arch_uprobe_post_xol() is silently ignored.
This doesn't look good and this can lead to the hard-to-debug problems.
1. Change handle_singlestep() to loudly complain and send SIGILL.
Note: this only affects x86, ppc/arm can't fail.
2. Change arch_uprobe_post_xol() to call arch_uprobe_abort_xol() and
avoid TF games if it is going to return an error.
This can help to to analyze the problem, if nothing else we should
not report ->ip = xol_slot in the core-file.
Note: this means that handle_riprel_post_xol() can be called twice,
but this is fine because it is idempotent.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Jim Keniston <jkenisto@us.ibm.com>
UPROBE_COPY_INSN, UPROBE_SKIP_SSTEP, and uprobe->flags must die. This
patch kills UPROBE_SKIP_SSTEP. I never understood why it was added;
not only it doesn't help, it harms.
It can only help to avoid arch_uprobe_skip_sstep() if it was already
called before and failed. But this is ugly, if we want to know whether
we can emulate this instruction or not we should do this analysis in
arch_uprobe_analyze_insn(), not when we hit this probe for the first
time.
And in fact this logic is simply wrong. arch_uprobe_skip_sstep() can
fail or not depending on the task/register state, if this insn can be
emulated but, say, put_user() fails we need to xol it this time, but
this doesn't mean we shouldn't try to emulate it when this or another
thread hits this bp next time.
And this is the actual reason for this change. We need to emulate the
"call" insn, but push(return-address) can obviously fail.
Per-arch notes:
x86: __skip_sstep() can only emulate "rep;nop". With this
change it will be called every time and most probably
for no reason.
This will be fixed by the next changes. We need to
change this suboptimal code anyway.
arm: Should not be affected. It has its own "bool simulate"
flag checked in arch_uprobe_skip_sstep().
ppc: Looks like, it can emulate almost everything. Does it
actually need to record the fact that emulate_step()
failed? Hopefully not. But if yes, it can add the ppc-
specific flag into arch_uprobe.
TODO: rename arch_uprobe_skip_sstep() to arch_uprobe_emulate_insn(),
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: David A. Long <dave.long@linaro.org>
Reviewed-by: Jim Keniston <jkenisto@us.ibm.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
If we hit the retry path, we'll call parse_cgroupfs_options() again,
but the string we pass to it has been modified by the previous call
to this function.
This bug can be observed by:
# mount -t cgroup -o name=foo,cpuset xxx /mnt && umount /mnt && \
mount -t cgroup -o name=foo,cpuset xxx /mnt
mount: wrong fs type, bad option, bad superblock on xxx,
missing codepage or helper program, or other error
...
The second mount passed "name=foo,cpuset" to the parser, and then it
hit the retry path and call the parser again, but this time the string
passed to the parser is "name=foo".
To fix this, we avoid calling parse_cgroupfs_options() again in this
case.
Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
We need to do it like we do for the other higher priority classes..
Signed-off-by: Kirill Tkhai <tkhai@yandex.ru>
Cc: Michael wang <wangyun@linux.vnet.ibm.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/336561397137116@web27h.yandex.ru
Signed-off-by: Ingo Molnar <mingo@kernel.org>
With the restructing of the function tracer working with instances, the
"top level" buffer is a bit special, as the function tracing is mapped
to the same set of filters. This is done by using a "global_ops" descriptor
and having the "set_ftrace_filter" and "set_ftrace_notrace" map to it.
When an instance is created, it creates the same files but its for the
local instance and not the global_ops.
The issues is that the local instance creation shares some code with
the global instance one and we end up trying to create th top level
"set_ftrace_*" files twice, and on boot up, we get an error like this:
Could not create debugfs 'set_ftrace_filter' entry
Could not create debugfs 'set_ftrace_notrace' entry
The reason they failed to be created was because they were created
twice, and the second time gives this error as you can not create the
same file twice.
Reported-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
