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When check_asym_packing() is triggered, the imbalance is set to:
busiest_stat.avg_load * busiest_stat.group_capacity / SCHED_CAPACITY_SCALE
But busiest_stat.avg_load equals:
sgs->group_load * SCHED_CAPACITY_SCALE / sgs->group_capacity
These divisions can generate a rounding that will make imbalance
slightly lower than the weighted load of the cfs_rq. But this is
enough to skip the rq in find_busiest_queue() and prevents asym
migration from happening.
Directly set imbalance to busiest's sgs->group_load to remove the
rounding.
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: valentin.schneider@arm.com
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Newly idle load balancing is not always triggered when a CPU becomes idle.
This prevents the scheduler from getting a chance to migrate the task
for asym packing.
Enable active migration during idle load balance too.
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: valentin.schneider@arm.com
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Traditionally hrtimer callbacks were run with IRQs disabled, but with
the introduction of HRTIMER_MODE_SOFT it is possible they run from
SoftIRQ context, which does _NOT_ have IRQs disabled.
Allow for the CFS bandwidth timers (period_timer and slack_timer) to
be ran from SoftIRQ context; this entails removing the assumption that
IRQs are already disabled from the locking.
While mainline doesn't strictly need this, -RT forces all timers not
explicitly marked with MODE_HARD into MODE_SOFT and trips over this.
And marking these timers as MODE_HARD doesn't make sense as they're
not required for RT operation and can potentially be quite expensive.
Reported-by: Tom Putzeys <tom.putzeys@be.atlascopco.com>
Tested-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190107125231.GE14122@hirez.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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All that fancy new Energy-Aware scheduling foo is hidden behind a
static_key, which is awesome if you have the stuff enabled in your
config.
However, when you lack all the prerequisites it doesn't make any sense
to pretend we'll ever actually run this, so provide a little more clue
to the compiler so it can more agressively delete the code.
text data bss dec hex filename
50297 976 96 51369 c8a9 defconfig-build/kernel/sched/fair.o
49227 944 96 50267 c45b defconfig-build/kernel/sched/fair.o
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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In its current state, Energy Aware Scheduling (EAS) starts automatically
on asymmetric platforms having an Energy Model (EM). However, there are
users who want to have an EM (for thermal management for example), but
don't want EAS with it.
In order to let users disable EAS explicitly, introduce a new sysctl
called 'sched_energy_aware'. It is enabled by default so that EAS can
start automatically on platforms where it makes sense. Flipping it to 0
rebuilds the scheduling domains and disables EAS.
Signed-off-by: Quentin Perret <quentin.perret@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: adharmap@codeaurora.org
Cc: chris.redpath@arm.com
Cc: currojerez@riseup.net
Cc: dietmar.eggemann@arm.com
Cc: edubezval@gmail.com
Cc: gregkh@linuxfoundation.org
Cc: javi.merino@kernel.org
Cc: joel@joelfernandes.org
Cc: juri.lelli@redhat.com
Cc: morten.rasmussen@arm.com
Cc: patrick.bellasi@arm.com
Cc: pkondeti@codeaurora.org
Cc: rjw@rjwysocki.net
Cc: skannan@codeaurora.org
Cc: smuckle@google.com
Cc: srinivas.pandruvada@linux.intel.com
Cc: thara.gopinath@linaro.org
Cc: tkjos@google.com
Cc: valentin.schneider@arm.com
Cc: vincent.guittot@linaro.org
Cc: viresh.kumar@linaro.org
Link: https://lkml.kernel.org/r/20181203095628.11858-11-quentin.perret@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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This patch adds JIT blinds support for JMP32.
Like BPF_JMP_REG/IMM, JMP32 version are needed for building raw bpf insn.
They are added to both include/linux/filter.h and
tools/include/linux/filter.h.
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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This patch implements interpreting new JMP32 instructions.
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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This patch teaches disassembler about JMP32. There are two places to
update:
- Class 0x6 now used by BPF_JMP32, not "unused".
- BPF_JMP32 need to show comparison operands properly.
The disassemble format is to add an extra "(32)" before the operands if
it is a sub-register. A better disassemble format for both JMP32 and
ALU32 just show the register prefix as "w" instead of "r", this is the
format using by LLVM assembler.
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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This patch teach verifier about the new BPF_JMP32 instruction class.
Verifier need to treat it similar as the existing BPF_JMP class.
A BPF_JMP32 insn needs to go through all checks that have been done on
BPF_JMP.
Also, verifier is doing runtime optimizations based on the extra info
conditional jump instruction could offer, especially when the comparison is
between constant and register that the value range of the register could be
improved based on the comparison results. These code are updated
accordingly.
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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The current min/max code does both signed and unsigned comparisons against
the input argument "val" which is "u64" and there is explicit type casting
when the comparison is signed.
As we will need slightly more complexer type casting when JMP32 introduced,
it is better to host the signed type casting. This makes the code more
clean with ignorable runtime overhead.
Also, code for J*GE/GT/LT/LE and JEQ/JNE are very similar, this patch
combine them.
The main purpose for this refactor is to make sure the min/max code will
still be readable and with minimum code duplication after JMP32 introduced.
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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The ever-evolving IS_ENABLED() macro is intended for CONFIG_* Kconfig
options, but rcuperf currently uses it for the decidedly non-CONFIG_*
MODULE macro. In the spirit of not inviting trouble, this commit
substitutes tried-and-true #ifdef.
Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
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Beyond a certain point in the CPU-hotplug offline process, timers get
stranded on the outgoing CPU, and won't fire until that CPU comes back
online, which might well be never. This commit therefore adds a hook
in torture_onoff_init() that is invoked from torture_offline(), which
rcutorture uses to occasionally wait for a grace period. This should
result in failures for RCU implementations that rely on stranded timers
eventually firing in the absence of the CPU coming back online.
Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
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This commit records grace periods in rcutorture's n_launders_hist[]
histogram, thus allowing rcu_torture_fwd_cb_hist() to print out the
elapsed number of grace periods between buckets. This information
helps to determine whether a lack of forward progress is due to stalled
grace periods on the one hand or due to sluggish callback invocation on
the other.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
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srcu_queue_delayed_work_on() disables preemption (and therefore CPU
hotplug in RCU's case) and then checks based on its own accounting if a
CPU is online. If the CPU is online it uses queue_delayed_work_on()
otherwise it fallbacks to queue_delayed_work().
The problem here is that queue_work() on -RT does not work with disabled
preemption.
queue_work_on() works also on an offlined CPU. queue_delayed_work_on()
has the problem that it is possible to program a timer on an offlined
CPU. This timer will fire once the CPU is online again. But until then,
the timer remains programmed and nothing will happen.
Add a local timer which will fire (as requested per delay) on the local
CPU and then enqueue the work on the specific CPU.
RCUtorture testing with SRCU-P for 24h showed no problems.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
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This commit updates the DYNTICK_IRQ_NONIDLE header comment to remove
the obsolete commentary about unmatched rcu_irq_{enter,exit}().
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
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This commit removes the "@irq" argument from the rcu_nmi_exit() docbook
header, given that this function now has no arguments.
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
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It turns out that it is queue_delayed_work_on() rather than
queue_work_on() that has difficulties when used concurrently with
CPU-hotplug removal operations. It is therefore unnecessary to protect
CPU identification and queue_work_on() with preempt_disable().
This commit therefore removes the preempt_disable() and preempt_enable()
from sync_rcu_exp_select_cpus(), which has the further benefit of reducing
the number of changes that must be maintained in the -rt patchset.
Reported-by: Thomas Gleixner <tglx@linutronix.de>
Reported-by: Sebastian Siewior <bigeasy@linutronix.de>
Suggested-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
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Although the name rcu_process_callbacks() still makes sense for Tiny
RCU, where most of what it does is invoke callbacks, it no longer makes
much sense for Tree RCU, especially given that the actually callback
invocation is relegated to rcu_do_batch(), or, for no-CBs CPUs, to the
rcuo kthreads. Especially in the latter case, rcu_process_callbacks()
has very little to do with actual callbacks. A better description of
this function is that it performs RCU's core processing.
This commit therefore changes the name of Tree RCU's rcu_process_callbacks()
function to rcu_core(), which also has the virtue of being consistent with
the existing invoke_rcu_core() function.
While in the area, the header comment is reworked.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
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The name rcu_check_callbacks() arguably made sense back in the early
2000s when RCU was quite a bit simpler than it is today, but it has
become quite misleading, especially with the advent of dyntick-idle
and NO_HZ_FULL. The rcu_check_callbacks() function is RCU's hook into
the scheduling-clock interrupt, and is now but one of many ways that
callbacks get promoted to invocable state.
This commit therefore changes the name to rcu_sched_clock_irq(),
which is the same number of characters and clearly indicates this
function's relation to the rest of the Linux kernel. In addition, for
the sake of consistency, rcu_flavor_check_callbacks() is also renamed
to rcu_flavor_sched_clock_irq().
While in the area, the header comments for both functions are reworked.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
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consolidate.2019.01.26a: RCU flavor consolidation cleanups.
fwd.2019.01.26a: RCU grace-period forward-progress fixes.
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Currently, __note_gp_changes() checks to see if the rcu_node structure's
->gp_seq_needed is greater than or equal to that of the rcu_data
structure, and if so, updates the rcu_data structure's ->gp_seq_needed
field. This results in a useless store in the case where the two fields
are equal.
This commit therefore carries out this store only in the case where the
rcu_node structure's ->gp_seq_needed is strictly greater than that of
the rcu_data structure.
Signed-off-by: "Zhang, Jun" <jun.zhang@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Link: https://lkml.kernel.org/r/88DC34334CA3444C85D647DBFA962C2735AD5F77@SHSMSX104.ccr.corp.intel.com
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The rcu_gp_kthread_wake() function is invoked when it might be necessary
to wake the RCU grace-period kthread. Because self-wakeups are normally
a useless waste of CPU cycles, if rcu_gp_kthread_wake() is invoked from
this kthread, it naturally refuses to do the wakeup.
Unfortunately, natural though it might be, this heuristic fails when
rcu_gp_kthread_wake() is invoked from an interrupt or softirq handler
that interrupted the grace-period kthread just after the final check of
the wait-event condition but just before the schedule() call. In this
case, a wakeup is required, even though the call to rcu_gp_kthread_wake()
is within the RCU grace-period kthread's context. Failing to provide
this wakeup can result in grace periods failing to start, which in turn
results in out-of-memory conditions.
This race window is quite narrow, but it actually did happen during real
testing. It would of course need to be fixed even if it was strictly
theoretical in nature.
This patch does not Cc stable because it does not apply cleanly to
earlier kernel versions.
Fixes: 48a7639ce80c ("rcu: Make callers awaken grace-period kthread")
Reported-by: "He, Bo" <bo.he@intel.com>
Co-developed-by: "Zhang, Jun" <jun.zhang@intel.com>
Co-developed-by: "He, Bo" <bo.he@intel.com>
Co-developed-by: "xiao, jin" <jin.xiao@intel.com>
Co-developed-by: Bai, Jie A <jie.a.bai@intel.com>
Signed-off: "Zhang, Jun" <jun.zhang@intel.com>
Signed-off: "He, Bo" <bo.he@intel.com>
Signed-off: "xiao, jin" <jin.xiao@intel.com>
Signed-off: Bai, Jie A <jie.a.bai@intel.com>
Signed-off-by: "Zhang, Jun" <jun.zhang@intel.com>
[ paulmck: Switch from !in_softirq() to "!in_interrupt() &&
!in_serving_softirq() to avoid redundant wakeups and to also handle the
interrupt-handler scenario as well as the softirq-handler scenario that
actually occurred in testing. ]
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Link: https://lkml.kernel.org/r/CD6925E8781EFD4D8E11882D20FC406D52A11F61@SHSMSX104.ccr.corp.intel.com
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Life is hard if RCU manages to get stuck without triggering RCU CPU
stall warnings or triggering the rcu_check_gp_start_stall() checks
for failing to start a grace period. This commit therefore adds a
boot-time-selectable sysrq key (commandeering "y") that allows manually
dumping Tree RCU state. The new rcutree.sysrq_rcu kernel boot parameter
must be set for this sysrq to be available.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
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The rcu_check_gp_kthread_starvation() function can be invoked without
holding locks, so the access to the rcu_state structure's ->gp_flags
field must be protected with READ_ONCE(). This commit therefore adds
this protection.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
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If a grace period fails to start (for example, because you commented
out the last two lines of rcu_accelerate_cbs_unlocked()), rcu_core()
will invoke rcu_check_gp_start_stall(), which will notice and complain.
However, this complaint is lacking crucial debugging information such
as when the last wakeup executed and what the value of ->gp_seq was at
that time. This commit therefore removes the current pr_alert() from
rcu_check_gp_start_stall(), instead invoking show_rcu_gp_kthreads(),
which has been updated to print the needed information, which is collected
by rcu_gp_kthread_wake().
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
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This commit updates a few obsolete comments in the RCU callback-offload
code.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
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The rcu_cpu_kthread_cpu used to provide debugfs information, but is no
longer used. This commit therefore removes it.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
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Given that RCU has a perfectly good per-CPU rcu_data structure, most
per-CPU quantities should be stored there.
This commit therefore moves the rcu_cpu_has_work per-CPU variable to
the rcu_data structure. This also makes this variable unconditionally
present, which should be acceptable given the memory reduction due to the
RCU flavor consolidation and also due to simplifications this will enable.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
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The rcu_cpu_kthread_loops variable used to provide debugfs information,
but is no longer used. This commit therefore removes it.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
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Given that RCU has a perfectly good per-CPU rcu_data structure, most
per-CPU quantities should be stored there.
This commit therefore moves the rcu_cpu_kthread_status per-CPU variable
to the rcu_data structure. This also makes this variable unconditionally
present, which should be acceptable given the memory reduction due to the
RCU flavor consolidation and also due to simplifications this will enable.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
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Given that RCU has a perfectly good per-CPU rcu_data structure, most
per-CPU quantities should be stored there.
This commit therefore moves the rcu_cpu_kthread_task per-CPU variable to
the rcu_data structure. This also makes this variable unconditionally
present, which should be acceptable given the memory reduction due to the
RCU flavor consolidation and also due to simplifications this will enable.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
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It is perfectly fine to set the rcutree.jiffies_till_first_fqs boot
parameter to zero, in fact, this can be useful on specialty systems that
usually have at least one idle CPU and that need fast grace periods.
This is because this setting causes the RCU grace-period kthread to
scan for idle threads immediately after grace-period initialization,
as opposed to waiting several jiffies to do so.
It is also perfectly fine to set the rcutree.rcu_kick_kthreads kernel
parameter, which gives the RCU grace-period kthread an extra wakeup
if it doesn't make progress for a period of three times the setting of
the rcutree.jiffies_till_first_fqs boot parameter. This is of course
problematic when the value of this parameter is zero, as it can result
in unnecessary wakeup IPIs along with unnecessary WARN_ONCE() invocations.
This commit therefore defers kthread kicking for at least two jiffies,
regardless of the setting of rcutree.jiffies_till_first_fqs.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
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Back when there were multiple flavors of RCU, it was necessary to
separately count lazy and non-lazy callbacks for each CPU. These counts
were used in CONFIG_RCU_FAST_NO_HZ kernels to determine how long a newly
idle CPU should be allowed to sleep before handling its RCU callbacks.
But now that there is only one flavor, the callback counts for a given
CPU's sole rcu_data structure are the counts for that CPU.
This commit therefore removes the rcu_data structure's ->nonlazy_posted
and ->nonlazy_posted_snap fields, the rcu_idle_count_callbacks_posted()
and rcu_cpu_has_callbacks() functions, repurposes the rcu_data structure's
->all_lazy field to record the laziness state at the beginning of the
latest idle sojourn, and modifies CONFIG_RCU_FAST_NO_HZ RCU CPU stall
warnings accordingly.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
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Now that _synchronize_rcu_expedited() has only one caller, and given that
this is a tail call, this commit inlines _synchronize_rcu_expedited()
into synchronize_rcu_expedited().
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
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Now that rcu_blocking_is_gp() makes the correct immediate-return
decision for both PREEMPT and !PREEMPT, a single implementation of
synchronize_rcu() will work correctly under both configurations.
This commit therefore eliminates a few lines of code by consolidating
the two implementations of synchronize_rcu().
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
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The CONFIG_PREEMPT=n and CONFIG_PREEMPT=y implementations of
synchronize_rcu_expedited() are quite similar, and with small
modifications to rcu_blocking_is_gp() can be made identical. This commit
therefore makes this change in order to save a few lines of code and to
reduce the amount of duplicate code.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
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Back when there could be multiple RCU flavors running in the same kernel
at the same time, it was necessary to specify the expedited grace-period
IPI handler at runtime. Now that there is only one RCU flavor, the
IPI handler can be determined at build time. There is therefore no
longer any reason for the RCU-preempt and RCU-sched IPI handlers to
have different names, nor is there any reason to pass these handlers in
function arguments and in the data structures enclosing workqueues.
This commit therefore makes all these changes, pushing the specification
of the expedited grace-period IPI handler down to the point of use.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
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The rcu_kthread_do_work() function has a single-line body and only one
remaining caller. This commit therefore saves a few lines of code by
inlining rcu_kthread_do_work() into its sole remaining caller.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
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Now that the RCU flavors have been consolidated, RCU_BH_FLAVOR and
RCU_SCHED_FLAVOR are no longer used. This commit therefore saves a
few lines by removing them.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
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Given that rcu_force_quiescent_state() is a simple wrapper around
force_quiescent_state(), this commit saves a few lines of code by
inlining force_quiescent_state() into rcu_force_quiescent_state(),
and changing all references to force_quiescent_state() to instead
invoke rcu_force_quiescent_state().
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
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During expedited RCU grace-period initialization, IPIs are sent to
all non-idle online CPUs. The IPI handler checks to see if the CPU is
in quiescent state, reporting one if so. This handler looks at three
different cases: (1) The CPU is not in an rcu_read_lock()-based critical
section, (2) The CPU is in the process of exiting an rcu_read_lock()-based
critical section, and (3) The CPU is in an rcu_read_lock()-based critical
section. In case (2), execution falls through into case (3).
This is harmless from a functionality viewpoint, but can result in
needless overhead during an improbable corner case. This commit therefore
adds the "return" statement needed to prevent fall-through.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
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Given RCU flavor consolidation, the name rcu_spawn_all_nocb_kthreads()
is quite misleading. It no longer ever creates more than one kthread,
and it does so only for the specified CPU. This commit therefore changes
this name to the more descriptive rcu_spawn_cpu_nocb_kthread(), and also
fixes up a similar issue in its header comment while in the area.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
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Now that synchronize_rcu() waits for preempt-disable regions of
code as well as RCU read-side critical sections, synchronize_sched()
can be replaced by synchronize_rcu(), in fact, synchronize_sched()
is now completely equivalent to synchronize_rcu(). This commit
therefore replaces synchronize_sched() with synchronize_rcu() so that
synchronize_sched() can eventually be removed entirely.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
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Now that call_rcu()'s callback is not invoked until after all
preempt-disable regions of code have completed (in addition to explicitly
marked RCU read-side critical sections), call_rcu() can be used in place
of call_rcu_sched(). This commit therefore makes that change.
While in the area, this commit also updates an outdated header comment
for for_each_domain().
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
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Pull together all the audit syscall watch, mark and tree prototypes and
stubs into the same ifdef.
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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Like commit 42d5e37654e4 ("audit: filter PATH records keyed on
filesystem magic") that addresses
https://github.com/linux-audit/audit-kernel/issues/8
Any user or remote filesystem could become unavailable and effectively
block on a forced unmount.
-a always,exit -S umount2 -F key=umount2
Provide a method to ignore these user and remote filesystems to prevent
them from being impossible to unmount.
Extend the "AUDIT_FILTER_FS" filter that uses the field type
AUDIT_FSTYPE keying off the filesystem 4-octet hexadecimal magic
identifier to filter specific filesystems to cover audit_inode() to address
this blockage.
An example rule would look like:
-a never,filesystem -F fstype=0x517B -F key=ignore_smb
-a never,filesystem -F fstype=0x6969 -F key=ignore_nfs
Arguably the better way to address this issue is to disable auditing
processes that touch removable filesystems.
Note: refactor __audit_inode_child() to remove two levels of if
indentation.
Please see the github issue tracker
https://github.com/linux-audit/audit-kernel/issues/100
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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This change ensures that the set*uid family of syscalls in kernel/sys.c
(setreuid, setuid, setresuid, setfsuid) all call ns_capable_common with
the CAP_OPT_INSETID flag, so capability checks in the security_capable
hook can know whether they are being called from within a set*uid
syscall. This change is a no-op by itself, but is needed for the
proposed SafeSetID LSM.
Signed-off-by: Micah Morton <mortonm@chromium.org>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: James Morris <james.morris@microsoft.com>
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V3 namespaced file capabilities were introduced in
commit 8db6c34f1dbc ("Introduce v3 namespaced file capabilities")
Add support for these by adding the "frootid" field to the existing
fcaps fields in the NAME and BPRM_FCAPS records.
Please see github issue
https://github.com/linux-audit/audit-kernel/issues/103
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
[PM: comment tweak to fit an 80 char line width]
Signed-off-by: Paul Moore <paul@paul-moore.com>
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loginuid and sessionid (and audit_log_session_info) should be part of
CONFIG_AUDIT scope and not CONFIG_AUDITSYSCALL since it is used in
CONFIG_CHANGE, ANOM_LINK, FEATURE_CHANGE (and INTEGRITY_RULE), none of
which are otherwise dependent on AUDITSYSCALL.
Please see github issue
https://github.com/linux-audit/audit-kernel/issues/104
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
[PM: tweaked subject line for better grep'ing]
Signed-off-by: Paul Moore <paul@paul-moore.com>
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The behavior of these system calls is slightly different between
architectures, as determined by the CONFIG_ARCH_WANT_IPC_PARSE_VERSION
symbol. Most architectures that implement the split IPC syscalls don't set
that symbol and only get the modern version, but alpha, arm, microblaze,
mips-n32, mips-n64 and xtensa expect the caller to pass the IPC_64 flag.
For the architectures that so far only implement sys_ipc(), i.e. m68k,
mips-o32, powerpc, s390, sh, sparc, and x86-32, we want the new behavior
when adding the split syscalls, so we need to distinguish between the
two groups of architectures.
The method I picked for this distinction is to have a separate system call
entry point: sys_old_*ctl() now uses ipc_parse_version, while sys_*ctl()
does not. The system call tables of the five architectures are changed
accordingly.
As an additional benefit, we no longer need the configuration specific
definition for ipc_parse_version(), it always does the same thing now,
but simply won't get called on architectures with the modern interface.
A small downside is that on architectures that do set
ARCH_WANT_IPC_PARSE_VERSION, we now have an extra set of entry points
that are never called. They only add a few bytes of bloat, so it seems
better to keep them compared to adding yet another Kconfig symbol.
I considered adding new syscall numbers for the IPC_64 variants for
consistency, but decided against that for now.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
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