22 Dec, 2020
1 commit
-
Export irq_handle_exit tracepoint, so that vendor modules
can register probes for this tracepoint.Bug: 175936268
Change-Id: I8e1eaffb7dd2f257e9c09412aad54ecca62bf019
Signed-off-by: Changki Kim
17 Dec, 2020
1 commit
-
Export irq_handle_entry tracepoint, so that vendor modules
can register probes for this tracepoint.Bug: 175806230
Change-Id: Iacc331f923d27f1a17065d6c0315c0c054af313e
Signed-off-by: Prasad Sodagudi
04 Dec, 2020
1 commit
-
Need to export internal scheduler symbols to facilitate vendor module
with scheduler based value-adds.Bug: 173725277
Change-Id: I021f09097dfc1480abcc998cc8e05e75b2ee828b
Signed-off-by: Shaleen Agrawal
Signed-off-by: Pavankumar Kondeti
11 Nov, 2020
5 commits
-
Tasklets are supposed to finish their work quickly and
should not block the current running process, but it is not
guaranteed that. Currently softirq_entry/exit can be used to
know total tasklets execution time, but not helpful to track
individual tasklet's execution time. With that we can't find
any culprit tasklet function, which is taking more time.Add {hi}-tasklet_entry/exit trace point support to track
individual tasklet execution.Bug: 168521633
Change-Id: I3496d15f64d020916774e673ccb4a8116ea2f2c9
Signed-off-by: Lingutla Chandrasekhar
[elavila: Port to mainline]
Signed-off-by: J. Avila -
Ksfotirqd is a normal priority CFS task. It can experience higher
scheduling latency under heavy load conditions. Currently once
asynchronous softirq processing is deferred to ksoftirqd, softirqs
are not processed further until ksoftirqd task gets a chance to run.
High latencies for softirqs like TIMER, HI TASKLET is not acceptable.So revert 'commit 4cd13c21b207 ("softirq: Let ksoftirqd do its job")'.
Bug: 168521633
Change-Id: I38a1a88b5f42dd534c65d739dbb7e4321a7904db
Signed-off-by: Lingutla Chandrasekhar
[satyap@codeaurora.org: Fix trivial merge conflicts]
Signed-off-by: Satya Durga Srinivasu Prabhala
[elavila: Port to mainline]
Signed-off-by: J. Avila -
This reverts commit 3c53776e29f81719efcf8f7a6e30cdf753bee94d because it
makes HI_SOFTIRQ and TASKLET_SOFTIRQ run immediately i.e. not get
deferred to ksfotirqd. The commit text calls out that this is a stopgap
until a better solution is deviced and that it should have included
TIMER_SOFTIRQ as well, but chose not to.Patch ebc7b75d772647813cdaf085c7f5adf3c90b033b from Qualcomm is a more
comprehensive solution which defers long running tasklets to ksfotirqd
when a rt task is interrupted.We cannot use both these together as they conflict; e.g. the original
makes TASKLET softirq run immediately while the Qualcomm one defers it
if rt gets interrupted. Choose to use the Qualcomm one.Bug: 168521633
Change-Id: I4af64cd7e2c4291dda5f503bf2d74ede459a76c6
Signed-off-by: Satya Durga Srinivasu Prabhala
[elavila: port to mainline, resolve conflicts, add commit text]
Signed-off-by: J. Avila -
Defer the softirq processing to ksoftirqd if a RT task is running
or queued on the current CPU. This complements the RT task placement
algorithm which tries to find a CPU that is not currently busy with
softirqs.Currently NET_TX, NET_RX, BLOCK and TASKLET softirqs are only deferred
as they can potentially run for long time.Bug: 168521633
Change-Id: Id7665244af6bbd5a96d9e591cf26154e9eaa860c
Signed-off-by: Pavankumar Kondeti
[satyap@codeaurora.org: trivial merge conflict resolution.]
Signed-off-by: Satya Durga Srinivasu Prabhala
[elavila: Port to mainline, squash with bugfix]
Signed-off-by: J. Avila -
The scheduling change to avoid putting RT threads on cores that
are handling softint's was catching cases where there was no reason
to believe the softint would take a long time, resulting in unnecessary
migration overhead. This patch reduces the migration to cases where
the core has a softint that is actually likely to take a long time,
as opposed to the RCU, SCHED, and TIMER softints that are rather quick.Bug: 31752786
Bug: 168521633
Change-Id: Ib4e179f1e15c736b2fdba31070494e357e9fbbe2
Signed-off-by: John Dias
[elavila: Amend commit text for AOSP, port to mainline]
Signed-off-by: J. Avila
16 Sep, 2020
1 commit
-
__raise_softirq_irqoff() must be called with interrupts disabled to protect
the per CPU softirq pending state update against an interrupt and soft
interrupt handling on return from interrupt.Add a lockdep assertion to validate the calling convention.
[ tglx: Massaged changelog ]
Signed-off-by: Jiafei Pan
Signed-off-by: Thomas Gleixner
Link: https://lore.kernel.org/r/20200814045522.45719-1-Jiafei.Pan@nxp.com
05 Aug, 2020
1 commit
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Pull tasklets API update from Kees Cook:
"These are the infrastructure updates needed to support converting the
tasklet API to something more modern (and hopefully for removal
further down the road).There is a 300-patch series waiting in the wings to get set out to
subsystem maintainers, but these changes need to be present in the
kernel first. Since this has some treewide changes, I carried this
series for -next instead of paining Thomas with it in -tip, but it's
got his Ack.This is similar to the timer_struct modernization from a while back,
but not nearly as messy (I hope). :)- Prepare for tasklet API modernization (Romain Perier, Allen Pais,
Kees Cook)"* tag 'tasklets-v5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
tasklet: Introduce new initialization API
treewide: Replace DECLARE_TASKLET() with DECLARE_TASKLET_OLD()
usb: gadget: udc: Avoid tasklet passing a global
31 Jul, 2020
1 commit
-
Nowadays, modern kernel subsystems that use callbacks pass the data
structure associated with a given callback as argument to the callback.
The tasklet subsystem remains one which passes an arbitrary unsigned
long to the callback function. This has several problems:- This keeps an extra field for storing the argument in each tasklet
data structure, it bloats the tasklet_struct structure with a redundant
.data field- No type checking can be performed on this argument. Instead of
using container_of() like other callback subsystems, it forces callbacks
to do explicit type cast of the unsigned long argument into the required
object type.- Buffer overflows can overwrite the .func and the .data field, so
an attacker can easily overwrite the function and its first argument
to whatever it wants.Add a new tasklet initialization API, via DECLARE_TASKLET() and
tasklet_setup(), which will replace the existing ones.This work is greatly inspired by the timer_struct conversion series,
see commit e99e88a9d2b0 ("treewide: setup_timer() -> timer_setup()")To avoid problems with both -Wcast-function-type (which is enabled in
the kernel via -Wextra is several subsystems), and with mismatched
function prototypes when build with Control Flow Integrity enabled,
this adds the "use_callback" member to let the tasklet caller choose
which union member to call through. Once all old API uses are removed,
this and the .data member will be removed as well. (On 64-bit this does
not grow the struct size as the new member fills the hole after atomic_t,
which is also "int" sized.)Signed-off-by: Romain Perier
Co-developed-by: Allen Pais
Signed-off-by: Allen Pais
Reviewed-by: Greg Kroah-Hartman
Acked-by: Thomas Gleixner
Co-developed-by: Kees Cook
Signed-off-by: Kees Cook
10 Jul, 2020
2 commits
-
Now that the macros use per-cpu data, we no longer need the argument.
Signed-off-by: Peter Zijlstra (Intel)
Reviewed-by: Ingo Molnar
Link: https://lkml.kernel.org/r/20200623083721.571835311@infradead.org -
Currently all IRQ-tracking state is in task_struct, this means that
task_struct needs to be defined before we use it.Especially for lockdep_assert_irq*() this can lead to header-hell.
Move the hardirq state into per-cpu variables to avoid the task_struct
dependency.Signed-off-by: Peter Zijlstra (Intel)
Reviewed-by: Ingo Molnar
Link: https://lkml.kernel.org/r/20200623083721.512673481@infradead.org
11 Jun, 2020
2 commits
-
Because:
irq_enter_rcu() includes lockdep_hardirq_enter()
irq_exit_rcu() does *NOT* include lockdep_hardirq_exit()Which resulted in two 'stray' lockdep_hardirq_exit() calls in
idtentry.h, and me spending a long time trying to find the matching
enter calls.Signed-off-by: Peter Zijlstra (Intel)
Signed-off-by: Thomas Gleixner
Link: https://lkml.kernel.org/r/20200529213321.359433429@infradead.org -
irq_enter()/exit() currently include RCU handling. To properly separate the RCU
handling code, provide variants which contain only the non-RCU related
functionality.Signed-off-by: Thomas Gleixner
Signed-off-by: Ingo Molnar
Reviewed-by: Andy Lutomirski
Link: https://lore.kernel.org/r/20200521202117.567023613@linutronix.de
21 Mar, 2020
3 commits
-
Continue what commit:
d820ac4c2fa8 ("locking: rename trace_softirq_[enter|exit] => lockdep_softirq_[enter|exit]")
started, rename these to avoid confusing them with tracepoints.
git grep -l "trace_\(soft\|hard\)\(irq_context\|irqs_enabled\)" | while read file;
do
sed -ie 's/trace_\(soft\|hard\)\(irq_context\|irqs_enabled\)/lockdep_\1\2/g' $file;
doneReported-by: Thomas Gleixner
Signed-off-by: Peter Zijlstra (Intel)
Signed-off-by: Thomas Gleixner
Reviewed-by: Thomas Gleixner
Acked-by: Will Deacon
Link: https://lkml.kernel.org/r/20200320115859.178626842@infradead.org -
Continue what commit:
d820ac4c2fa8 ("locking: rename trace_softirq_[enter|exit] => lockdep_softirq_[enter|exit]")
started, rename these to avoid confusing them with tracepoints.
git grep -l "trace_softirqs_\(on\|off\)" | while read file;
do
sed -ie 's/trace_softirqs_\(on\|off\)/lockdep_softirqs_\1/g' $file;
doneReported-by: Thomas Gleixner
Signed-off-by: Peter Zijlstra (Intel)
Signed-off-by: Thomas Gleixner
Reviewed-by: Thomas Gleixner
Acked-by: Will Deacon
Link: https://lkml.kernel.org/r/20200320115859.119434738@infradead.org -
Continue what commit:
d820ac4c2fa8 ("locking: rename trace_softirq_[enter|exit] => lockdep_softirq_[enter|exit]")
started, rename these to avoid confusing them with tracepoints.
Signed-off-by: Thomas Gleixner
Reviewed-by: Thomas Gleixner
Acked-by: Will Deacon
Link: https://lkml.kernel.org/r/20200320115859.060481361@infradead.org
09 Jul, 2019
1 commit
-
Pull irq updates from Thomas Gleixner:
"The irq departement provides the usual mixed bag:Core:
- Further improvements to the irq timings code which aims to predict
the next interrupt for power state selection to achieve better
latency/power balance- Add interrupt statistics to the core NMI handlers
- The usual small fixes and cleanups
Drivers:
- Support for Renesas RZ/A1, Annapurna Labs FIC, Meson-G12A SoC and
Amazon Gravition AMR/GIC interrupt controllers.- Rework of the Renesas INTC controller driver
- ACPI support for Socionext SoCs
- Enhancements to the CSKY interrupt controller
- The usual small fixes and cleanups"
* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (39 commits)
irq/irqdomain: Fix comment typo
genirq: Update irq stats from NMI handlers
irqchip/gic-pm: Remove PM_CLK dependency
irqchip/al-fic: Introduce Amazon's Annapurna Labs Fabric Interrupt Controller Driver
dt-bindings: interrupt-controller: Add Amazon's Annapurna Labs FIC
softirq: Use __this_cpu_write() in takeover_tasklets()
irqchip/mbigen: Stop printing kernel addresses
irqchip/gic: Add dependency for ARM_GIC_MAX_NR
genirq/affinity: Remove unused argument from [__]irq_build_affinity_masks()
genirq/timings: Add selftest for next event computation
genirq/timings: Add selftest for irqs circular buffer
genirq/timings: Add selftest for circular array
genirq/timings: Encapsulate storing function
genirq/timings: Encapsulate timings push
genirq/timings: Optimize the period detection speed
genirq/timings: Fix timings buffer inspection
genirq/timings: Fix next event index function
irqchip/qcom: Use struct_size() in devm_kzalloc()
irqchip/irq-csky-mpintc: Remove unnecessary loop in interrupt handler
dt-bindings: interrupt-controller: Update csky mpintc
...
24 Jun, 2019
1 commit
-
The code is executed with interrupts disabled, so it's safe to use
__this_cpu_write().[ tglx: Massaged changelog ]
Signed-off-by: Muchun Song
Signed-off-by: Thomas Gleixner
Cc: joel@joelfernandes.org
Cc: rostedt@goodmis.org
Cc: frederic@kernel.org
Cc: paulmck@linux.vnet.ibm.com
Cc: alexander.levin@verizon.com
Cc: peterz@infradead.org
Link: https://lkml.kernel.org/r/20190618143305.2038-1-smuchun@gmail.com
05 Jun, 2019
1 commit
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Based on 1 normalized pattern(s):
distribute under gplv2
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 8 file(s).
Signed-off-by: Thomas Gleixner
Reviewed-by: Armijn Hemel
Reviewed-by: Allison Randal
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531190114.475576622@linutronix.de
Signed-off-by: Greg Kroah-Hartman
22 Mar, 2019
1 commit
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There are no more users of this interface.
Remove it.Signed-off-by: Thomas Gleixner
Signed-off-by: Anna-Maria Gleixner
Signed-off-by: Sebastian Andrzej Siewior
Signed-off-by: Thomas Gleixner
Acked-by: David S. Miller
Cc: netdev@vger.kernel.org
Link: https://lkml.kernel.org/r/20190301224821.29843-4-bigeasy@linutronix.de
11 Feb, 2019
1 commit
-
When a CPU is unplugged the kernel threads of this CPU are parked (see
smpboot_park_threads()). kthread_park() is used to mark each thread as
parked and wake it up, so it can complete the process of parking itselfs
(see smpboot_thread_fn()).If local softirqs are pending on interrupt exit invoke_softirq() is called
to process the softirqs, however it skips processing when the softirq
kernel thread of the local CPU is scheduled to run. The softirq kthread is
one of the threads that is parked when a CPU is unplugged. Parking the
kthread wakes it up, however only to complete the parking process, not to
process the pending softirqs. Hence processing of softirqs at the end of an
interrupt is skipped, but not done elsewhere, which can result in warnings
about pending softirqs when a CPU is unplugged:/sys/devices/system/cpu # echo 0 > cpu4/online
[ ... ] NOHZ: local_softirq_pending 02
[ ... ] NOHZ: local_softirq_pending 202
[ ... ] CPU4: shutdown
[ ... ] psci: CPU4 killed.Don't skip processing of softirqs at the end of an interrupt when the
softirq thread of the CPU is parking.Signed-off-by: Matthias Kaehlcke
Signed-off-by: Thomas Gleixner
Cc: Peter Zijlstra
Cc: Steven Rostedt
Cc: "Paul E . McKenney"
Cc: Sebastian Andrzej Siewior
Cc: Douglas Anderson
Cc: Stephen Boyd
Link: https://lkml.kernel.org/r/20190128234625.78241-3-mka@chromium.org
26 Oct, 2018
1 commit
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Pull irq updates from Thomas Gleixner:
"The interrupt brigade came up with the following updates:- Driver for the Marvell System Error Interrupt machinery
- Overhaul of the GIC-V3 ITS driver
- Small updates and fixes all over the place"
* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (31 commits)
genirq: Fix race on spurious interrupt detection
softirq: Fix typo in __do_softirq() comments
genirq: Fix grammar s/an /a /
irqchip/gic: Unify GIC priority definitions
irqchip/gic-v3: Remove acknowledge loop
dt-bindings/interrupt-controller: Add documentation for Marvell SEI controller
dt-bindings/interrupt-controller: Update Marvell ICU bindings
irqchip/irq-mvebu-icu: Add support for System Error Interrupts (SEI)
arm64: marvell: Enable SEI driver
irqchip/irq-mvebu-sei: Add new driver for Marvell SEI
irqchip/irq-mvebu-icu: Support ICU subnodes
irqchip/irq-mvebu-icu: Disociate ICU and NSR
irqchip/irq-mvebu-icu: Clarify the reset operation of configured interrupts
irqchip/irq-mvebu-icu: Fix wrong private data retrieval
dt-bindings/interrupt-controller: Fix Marvell ICU length in the example
genirq/msi: Allow creation of a tree-based irqdomain for platform-msi
dt-bindings: irqchip: renesas-irqc: Document r8a7744 support
dt-bindings: irqchip: renesas-irqc: Document R-Car E3 support
irqchip/pdc: Setup all edge interrupts as rising edge at GIC
irqchip/gic-v3-its: Allow use of LPI tables in reserved memory
...
19 Oct, 2018
1 commit
-
s/s/as
[ mingo: Also add a missing 'the', add proper punctuation and clarify what 'swap' means here. ]
Signed-off-by: Yangtao Li
Cc: Linus Torvalds
Cc: Peter Zijlstra
Cc: Thomas Gleixner
Cc: alexander.levin@verizon.com
Cc: frederic@kernel.org
Cc: joel@joelfernandes.org
Cc: paulmck@linux.vnet.ibm.com
Cc: rostedt@goodmis.org
Link: http://lkml.kernel.org/r/20181018142133.12341-1-tiny.windzz@gmail.com
Signed-off-by: Ingo Molnar
31 Aug, 2018
2 commits
-
Now that the main RCU API knows about softirq disabling and softirq's
quiescent states, the RCU-bh update code can be dispensed with.
This commit therefore removes the RCU-bh update-side implementation and
defines RCU-bh's update-side API in terms of that of either RCU-preempt or
RCU-sched, depending on the setting of the CONFIG_PREEMPT Kconfig option.In kernels built with CONFIG_RCU_NOCB_CPU=y this has the knock-on effect
of reducing by one the number of rcuo kthreads per CPU.Signed-off-by: Paul E. McKenney
-
One necessary step towards consolidating the three flavors of RCU is to
make sure that the resulting consolidated "one flavor to rule them all"
correctly handles networking denial-of-service attacks. One thing that
allows RCU-bh to do so is that __do_softirq() invokes rcu_bh_qs() every
so often, and so something similar has to happen for consolidated RCU.This must be done carefully. For example, if a preemption-disabled
region of code takes an interrupt which does softirq processing before
returning, consolidated RCU must ignore the resulting rcu_bh_qs()
invocations -- preemption is still disabled, and that means an RCU
reader for the consolidated flavor.This commit therefore creates a new rcu_softirq_qs() that is called only
from the ksoftirqd task, thus avoiding the interrupted-a-preempted-region
problem. This new rcu_softirq_qs() function invokes rcu_sched_qs(),
rcu_preempt_qs(), and rcu_preempt_deferred_qs(). The latter call handles
any deferred quiescent states.Note that __do_softirq() still invokes rcu_bh_qs(). It will continue to
do so until a later stage of cleanup when the RCU-bh flavor is removed.Signed-off-by: Paul E. McKenney
[ paulmck: Fix !SMP issue located by kbuild test robot. ]
03 Aug, 2018
1 commit
-
The full nohz tick is reprogrammed in irq_exit() only if the exit is not in
a nesting interrupt. This stands as an optimization: whether a hardirq or a
softirq is interrupted, the tick is going to be reprogrammed when necessary
at the end of the inner interrupt, with even potential new updates on the
timer queue.When soft interrupts are interrupted, it's assumed that they are executing
on the tail of an interrupt return. In that case tick_nohz_irq_exit() is
called after softirq processing to take care of the tick reprogramming.But the assumption is wrong: softirqs can be processed inline as well, ie:
outside of an interrupt, like in a call to local_bh_enable() or from
ksoftirqd.Inline softirqs don't reprogram the tick once they are done, as opposed to
interrupt tail softirq processing. So if a tick interrupts an inline
softirq processing, the next timer will neither be reprogrammed from the
interrupting tick's irq_exit() nor after the interrupted softirq
processing. This situation may leave the tick unprogrammed while timers are
armed.To fix this, simply keep reprogramming the tick even if a softirq has been
interrupted. That can be optimized further, but for now correctness is more
important.Note that new timers enqueued in nohz_full mode after a softirq gets
interrupted will still be handled just fine through self-IPIs triggered by
the timer code.Reported-by: Anna-Maria Gleixner
Signed-off-by: Frederic Weisbecker
Signed-off-by: Thomas Gleixner
Tested-by: Anna-Maria Gleixner
Cc: stable@vger.kernel.org # 4.14+
Link: https://lkml.kernel.org/r/1533303094-15855-1-git-send-email-frederic@kernel.org
18 Jul, 2018
1 commit
-
Way back in 4.9, we committed 4cd13c21b207 ("softirq: Let ksoftirqd do
its job"), and ever since we've had small nagging issues with it. For
example, we've had:1ff688209e2e ("watchdog: core: make sure the watchdog_worker is not deferred")
8d5755b3f77b ("watchdog: softdog: fire watchdog even if softirqs do not get to run")
217f69743681 ("net: busy-poll: allow preemption in sk_busy_loop()")all of which worked around some of the effects of that commit.
The DVB people have also complained that the commit causes excessive USB
URB latencies, which seems to be due to the USB code using tasklets to
schedule USB traffic. This seems to be an issue mainly when already
living on the edge, but waiting for ksoftirqd to handle it really does
seem to cause excessive latencies.Now Hanna Hawa reports that this issue isn't just limited to USB URB and
DVB, but also causes timeout problems for the Marvell SoC team:"I'm facing kernel panic issue while running raid 5 on sata disks
connected to Macchiatobin (Marvell community board with Armada-8040
SoC with 4 ARMv8 cores of CA72) Raid 5 built with Marvell DMA engine
and async_tx mechanism (ASYNC_TX_DMA [=y]); the DMA driver (mv_xor_v2)
uses a tasklet to clean the done descriptors from the queue"The latency problem causes a panic:
mv_xor_v2 f0400000.xor: dma_sync_wait: timeout!
Kernel panic - not syncing: async_tx_quiesce: DMA error waiting for transactionWe've discussed simply just reverting the original commit entirely, and
also much more involved solutions (with per-softirq threads etc). This
patch is intentionally stupid and fairly limited, because the issue
still remains, and the other solutions either got sidetracked or had
other issues.We should probably also consider the timer softirqs to be synchronous
and not be delayed to ksoftirqd (since they were the issue with the
earlier watchdog problems), but that should be done as a separate patch.
This does only the tasklet cases.Reported-and-tested-by: Hanna Hawa
Reported-and-tested-by: Josef Griebichler
Reported-by: Mauro Carvalho Chehab
Cc: Alan Stern
Cc: Greg Kroah-Hartman
Cc: Eric Dumazet
Cc: Ingo Molnar
Signed-off-by: Linus Torvalds
22 Jun, 2018
1 commit
-
I'm able to reproduce a lockdep splat with config options:
CONFIG_PROVE_LOCKING=y,
CONFIG_DEBUG_LOCK_ALLOC=y and
CONFIG_PREEMPTIRQ_EVENTS=y$ echo 1 > /d/tracing/events/preemptirq/preempt_enable/enable
[ 26.112609] DEBUG_LOCKS_WARN_ON(current->softirqs_enabled)
[ 26.112636] WARNING: CPU: 0 PID: 118 at kernel/locking/lockdep.c:3854
[...]
[ 26.144229] Call Trace:
[ 26.144926]
[ 26.145506] lock_acquire+0x55/0x1b0
[ 26.146499] ? __do_softirq+0x46f/0x4d9
[ 26.147571] ? __do_softirq+0x46f/0x4d9
[ 26.148646] trace_preempt_on+0x8f/0x240
[ 26.149744] ? trace_preempt_on+0x4d/0x240
[ 26.150862] ? __do_softirq+0x46f/0x4d9
[ 26.151930] preempt_count_sub+0x18a/0x1a0
[ 26.152985] __do_softirq+0x46f/0x4d9
[ 26.153937] irq_exit+0x68/0xe0
[ 26.154755] smp_apic_timer_interrupt+0x271/0x280
[ 26.156056] apic_timer_interrupt+0xf/0x20
[ 26.157105]The issue was this:
preempt_count = 1 << SOFTIRQ_SHIFT
__local_bh_enable(cnt = 1 << SOFTIRQ_SHIFT) {
if (softirq_count() == (cnt && SOFTIRQ_MASK)) {
trace_softirqs_on() {
current->softirqs_enabled = 1;
}
}
preempt_count_sub(cnt) {
trace_preempt_on() {
tracepoint() {
rcu_read_lock_sched() {
// jumps into lockdepWhere preempt_count still has softirqs disabled, but
current->softirqs_enabled is true, and we get a splat.Link: http://lkml.kernel.org/r/20180607201143.247775-1-joel@joelfernandes.org
Cc: Peter Zijlstra
Cc: Ingo Molnar
Cc: Linus Torvalds
Cc: Mathieu Desnoyers
Cc: Tom Zanussi
Cc: Namhyung Kim
Cc: Thomas Glexiner
Cc: Boqun Feng
Cc: Paul McKenney
Cc: Masami Hiramatsu
Cc: Todd Kjos
Cc: Erick Reyes
Cc: Julia Cartwright
Cc: Byungchul Park
Cc: stable@vger.kernel.org
Reviewed-by: Steven Rostedt (VMware)
Fixes: d59158162e032 ("tracing: Add support for preempt and irq enable/disable events")
Signed-off-by: Joel Fernandes (Google)
Signed-off-by: Steven Rostedt (VMware)
05 Jun, 2018
1 commit
-
Pull irq updates from Thomas Gleixner:
- Consolidation of softirq pending:
The softirq mask and its accessors/mutators have many implementations
scattered around many architectures. Most do the same things
consisting in a field in a per-cpu struct (often irq_cpustat_t)
accessed through per-cpu ops. We can provide instead a generic
efficient version that most of them can use. In fact s390 is the only
exception because the field is stored in lowcore.- Support for level!?! triggered MSI (ARM)
Over the past couple of years, we've seen some SoCs coming up with
ways of signalling level interrupts using a new flavor of MSIs, where
the MSI controller uses two distinct messages: one that raises a
virtual line, and one that lowers it. The target MSI controller is in
charge of maintaining the state of the line.This allows for a much simplified HW signal routing (no need to have
hundreds of discrete lines to signal level interrupts if you already
have a memory bus), but results in a departure from the current idea
the kernel has of MSIs.- Support for Meson-AXG GPIO irqchip
- Large stm32 irqchip rework (suspend/resume, hierarchical domains)
- More SPDX conversions
* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits)
ARM: dts: stm32: Add exti support to stm32mp157 pinctrl
ARM: dts: stm32: Add exti support for stm32mp157c
pinctrl/stm32: Add irq_eoi for stm32gpio irqchip
irqchip/stm32: Add suspend/resume support for hierarchy domain
irqchip/stm32: Add stm32mp1 support with hierarchy domain
irqchip/stm32: Prepare common functions
irqchip/stm32: Add host and driver data structures
irqchip/stm32: Add suspend support
irqchip/stm32: Add falling pending register support
irqchip/stm32: Checkpatch fix
irqchip/stm32: Optimizes and cleans up stm32-exti irq_domain
irqchip/meson-gpio: Add support for Meson-AXG SoCs
dt-bindings: interrupt-controller: New binding for Meson-AXG SoC
dt-bindings: interrupt-controller: Fix the double quotes
softirq/s390: Move default mutators of overwritten softirq mask to s390
softirq/x86: Switch to generic local_softirq_pending() implementation
softirq/sparc: Switch to generic local_softirq_pending() implementation
softirq/powerpc: Switch to generic local_softirq_pending() implementation
softirq/parisc: Switch to generic local_softirq_pending() implementation
softirq/ia64: Switch to generic local_softirq_pending() implementation
...
16 May, 2018
1 commit
-
The cond_resched_softirq() macro is not used anywhere in mainline, so
this commit simplifies the kernel by eliminating it.Suggested-by: Eric Dumazet
Signed-off-by: Paul E. McKenney
Cc: Ingo Molnar
Acked-by: Peter Zijlstra (Intel)
Reviewed-by: Eric Dumazet
Tested-by: Nicholas Piggin
14 May, 2018
1 commit
-
In order to optimize and consolidate softirq mask accesses, let's
convert the default irq_cpustat_t implementation to per-CPU standard API.Signed-off-by: Frederic Weisbecker
Acked-by: Thomas Gleixner
Acked-by: Peter Zijlstra
Cc: Benjamin Herrenschmidt
Cc: David S. Miller
Cc: Fenghua Yu
Cc: Heiko Carstens
Cc: Helge Deller
Cc: James E.J. Bottomley
Cc: Linus Torvalds
Cc: Martin Schwidefsky
Cc: Michael Ellerman
Cc: Paul Mackerras
Cc: Rich Felker
Cc: Sebastian Andrzej Siewior
Cc: Tony Luck
Cc: Yoshinori Sato
Link: http://lkml.kernel.org/r/1525786706-22846-5-git-send-email-frederic@kernel.org
Signed-off-by: Ingo Molnar
09 Mar, 2018
2 commits
-
tasklet_action() + tasklet_hi_action() are almost identical. Move the
common code from both function into __tasklet_action_common() and let
both functions invoke it with different arguments.[ bigeasy: Splitted out from RT's "tasklet: Prevent tasklets from going
into infinite spin in RT" and added commit message]Signed-off-by: Ingo Molnar
Signed-off-by: Steven Rostedt
Signed-off-by: Thomas Gleixner
Signed-off-by: Sebastian Andrzej Siewior
Cc: Julia Cartwright
Link: https://lkml.kernel.org/r/20180227164808.10093-3-bigeasy@linutronix.de -
__tasklet_schedule() and __tasklet_hi_schedule() are almost identical.
Move the common code from both function into __tasklet_schedule_common()
and let both functions invoke it with different arguments.[ bigeasy: Splitted out from RT's "tasklet: Prevent tasklets from going
into infinite spin in RT" and added commit message. Use
this_cpu_ptr(headp) in __tasklet_schedule_common() as suggested
by Julia Cartwright ]Signed-off-by: Ingo Molnar
Signed-off-by: Steven Rostedt
Signed-off-by: Thomas Gleixner
Signed-off-by: Sebastian Andrzej Siewior
Cc: Julia Cartwright
Link: https://lkml.kernel.org/r/20180227164808.10093-2-bigeasy@linutronix.de
05 Dec, 2017
1 commit
-
Now that cond_resched() also provides RCU quiescent states when
needed, it can be used in place of cond_resched_rcu_qs(). This
commit therefore makes this change.Signed-off-by: Paul E. McKenney
Cc: NeilBrown
Cc: Ingo Molnar
16 Nov, 2017
1 commit
-
Fix up makefiles, remove references, and git rm kmemcheck.
Link: http://lkml.kernel.org/r/20171007030159.22241-4-alexander.levin@verizon.com
Signed-off-by: Sasha Levin
Cc: Steven Rostedt
Cc: Vegard Nossum
Cc: Pekka Enberg
Cc: Michal Hocko
Cc: Eric W. Biederman
Cc: Alexander Potapenko
Cc: Tim Hansen
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
08 Nov, 2017
1 commit
-
Use lockdep to check that IRQs are enabled or disabled as expected. This
way the sanity check only shows overhead when concurrency correctness
debug code is enabled.Signed-off-by: Frederic Weisbecker
Acked-by: Thomas Gleixner
Cc: David S . Miller
Cc: Lai Jiangshan
Cc: Linus Torvalds
Cc: Paul E. McKenney
Cc: Peter Zijlstra
Cc: Tejun Heo
Link: http://lkml.kernel.org/r/1509980490-4285-3-git-send-email-frederic@kernel.org
Signed-off-by: Ingo Molnar
11 Apr, 2017
1 commit
-
It is not safe for one thread to modify the ->flags
of another thread as there is no locking that can protect
the update.So tsk_restore_flags(), which takes a task pointer and modifies
the flags, is an invitation to do the wrong thing.All current users pass "current" as the task, so no developers have
accepted that invitation. It would be best to ensure it remains
that way.So rename tsk_restore_flags() to current_restore_flags() and don't
pass in a task_struct pointer. Always operate on current->flags.Signed-off-by: NeilBrown
Cc: Linus Torvalds
Cc: Mel Gorman
Cc: Michal Hocko
Cc: Peter Zijlstra
Cc: Thomas Gleixner
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar
22 Oct, 2016
1 commit
-
This library was moved to the generic area and was
renamed to irq-poll. Hence, update proc/softirqs output accordingly.Signed-off-by: Sagi Grimberg
Reviewed-by: Johannes Thumshirn
Reviewed-by: Christoph Hellwig
Signed-off-by: Jens Axboe
