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2022-02-23sched/headers: Introduce kernel/sched/build_utility.c and build multiple .c files thereIngo Molnar1-1/+0
Collect all utility functionality source code files into a single kernel/sched/build_utility.c file, via #include-ing the .c files: kernel/sched/clock.c kernel/sched/completion.c kernel/sched/loadavg.c kernel/sched/swait.c kernel/sched/wait_bit.c kernel/sched/wait.c CONFIG_CPU_FREQ: kernel/sched/cpufreq.c CONFIG_CPU_FREQ_GOV_SCHEDUTIL: kernel/sched/cpufreq_schedutil.c CONFIG_CGROUP_CPUACCT: kernel/sched/cpuacct.c CONFIG_SCHED_DEBUG: kernel/sched/debug.c CONFIG_SCHEDSTATS: kernel/sched/stats.c CONFIG_SMP: kernel/sched/cpupri.c kernel/sched/stop_task.c kernel/sched/topology.c CONFIG_SCHED_CORE: kernel/sched/core_sched.c CONFIG_PSI: kernel/sched/psi.c CONFIG_MEMBARRIER: kernel/sched/membarrier.c CONFIG_CPU_ISOLATION: kernel/sched/isolation.c CONFIG_SCHED_AUTOGROUP: kernel/sched/autogroup.c The goal is to amortize the 60+ KLOC header bloat from over a dozen build units into a single build unit. The build time of build_utility.c also roughly matches the build time of core.c and fair.c - allowing better load-balancing of scheduler-only rebuilds. Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Peter Zijlstra <peterz@infradead.org>
2022-02-16sched/isolation: Split housekeeping cpumask per isolation featuresFrederic Weisbecker1-29/+62
To prepare for supporting each housekeeping feature toward cpuset, split the global housekeeping cpumask per HK_TYPE_* entry. This will later allow, for example, to runtime modify the cpulist passed through "isolcpus=", "nohz_full=" and "rcu_nocbs=" kernel boot parameters. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Juri Lelli <juri.lelli@redhat.com> Reviewed-by: Phil Auld <pauld@redhat.com> Link: https://lore.kernel.org/r/20220207155910.527133-9-frederic@kernel.org
2022-02-16sched/isolation: Fix housekeeping_mask memory leakFrederic Weisbecker1-9/+10
If "nohz_full=" or "isolcpus=nohz" are called with CONFIG_NO_HZ_FULL=n, housekeeping_mask doesn't get freed despite it being unused if housekeeping_setup() is called for the first time. Check this scenario first to fix this, so that no useless allocation is performed. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Juri Lelli <juri.lelli@redhat.com> Reviewed-by: Paul E. McKenney <paulmck@kernel.org> Reviewed-by: Phil Auld <pauld@redhat.com> Link: https://lore.kernel.org/r/20220207155910.527133-8-frederic@kernel.org
2022-02-16sched/isolation: Consolidate error handlingFrederic Weisbecker1-10/+9
Centralize the mask freeing and return value for the error path. This makes potential leaks more visible. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Juri Lelli <juri.lelli@redhat.com> Reviewed-by: Phil Auld <pauld@redhat.com> Link: https://lore.kernel.org/r/20220207155910.527133-7-frederic@kernel.org
2022-02-16sched/isolation: Consolidate check for housekeeping minimum serviceFrederic Weisbecker1-18/+17
There can be two subsequent calls to housekeeping_setup() due to "nohz_full=" and "isolcpus=" that can mix up. The two passes each have their own way to deal with an empty housekeeping set of CPUs. Consolidate this part and remove the awful "tmp" based naming. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Juri Lelli <juri.lelli@redhat.com> Reviewed-by: Phil Auld <pauld@redhat.com> Link: https://lore.kernel.org/r/20220207155910.527133-6-frederic@kernel.org
2022-02-16sched/isolation: Use single feature type while referring to housekeeping cpumaskFrederic Weisbecker1-10/+22
Refer to housekeeping APIs using single feature types instead of flags. This prevents from passing multiple isolation features at once to housekeeping interfaces, which soon won't be possible anymore as each isolation features will have their own cpumask. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Juri Lelli <juri.lelli@redhat.com> Reviewed-by: Phil Auld <pauld@redhat.com> Link: https://lore.kernel.org/r/20220207155910.527133-5-frederic@kernel.org
2021-05-13sched/isolation: Reconcile rcu_nocbs= and nohz_full=Paul Gortmaker1-3/+1
We have a mismatch between RCU and isolation -- in relation to what is considered the maximum valid CPU number. This matters because nohz_full= and rcu_nocbs= are joined at the hip; in fact the former will enforce the latter. So we don't want a CPU mask to be valid for one and denied for the other. The difference 1st appeared as of v4.15; further details are below. As it is confusing to anyone who isn't looking at the code regularly, a reminder is in order; three values exist here: CONFIG_NR_CPUS - compiled in maximum cap on number of CPUs supported. nr_cpu_ids - possible # of CPUs (typically reflects what ACPI says) cpus_present - actual number of present/detected/installed CPUs. For this example, I'll refer to NR_CPUS=64 from "make defconfig" and nr_cpu_ids=6 for ACPI reporting on a board that could run a six core, and present=4 for a quad that is physically in the socket. From dmesg: smpboot: Allowing 6 CPUs, 2 hotplug CPUs setup_percpu: NR_CPUS:64 nr_cpumask_bits:64 nr_cpu_ids:6 nr_node_ids:1 rcu: RCU restricting CPUs from NR_CPUS=64 to nr_cpu_ids=6. smp: Brought up 1 node, 4 CPUs And from userspace, see: paul@trash:/sys/devices/system/cpu$ cat present 0-3 paul@trash:/sys/devices/system/cpu$ cat possible 0-5 paul@trash:/sys/devices/system/cpu$ cat kernel_max 63 Everything is fine if we boot 5x5 for rcu/nohz: Command line: BOOT_IMAGE=/boot/bzImage nohz_full=2-5 rcu_nocbs=2-5 root=/dev/sda1 ro NO_HZ: Full dynticks CPUs: 2-5. rcu: Offload RCU callbacks from CPUs: 2-5. ..even though there is no CPU 4 or 5. Both RCU and nohz_full are OK. Now we push that > 6 but less than NR_CPU and with 15x15 we get: Command line: BOOT_IMAGE=/boot/bzImage rcu_nocbs=2-15 nohz_full=2-15 root=/dev/sda1 ro rcu: Note: kernel parameter 'rcu_nocbs=', 'nohz_full', or 'isolcpus=' contains nonexistent CPUs. rcu: Offload RCU callbacks from CPUs: 2-5. These are both functionally equivalent, as we are only changing flags on phantom CPUs that don't exist, but note the kernel interpretation changes. And worse, it only changes for one of the two - which is the problem. RCU doesn't care if you want to restrict the flags on phantom CPUs but clearly nohz_full does after this change from v4.15. edb9382175c3: ("sched/isolation: Move isolcpus= handling to the housekeeping code") - if (cpulist_parse(str, non_housekeeping_mask) < 0) { - pr_warn("Housekeeping: Incorrect nohz_full cpumask\n"); + err = cpulist_parse(str, non_housekeeping_mask); + if (err < 0 || cpumask_last(non_housekeeping_mask) >= nr_cpu_ids) { + pr_warn("Housekeeping: nohz_full= or isolcpus= incorrect CPU range\n"); To be clear, the sanity check on "possible" (nr_cpu_ids) is new here. The goal was reasonable ; not wanting housekeeping to land on a not-possible CPU, but note two things: 1) this is an exclusion list, not an inclusion list; we are tracking non_housekeeping CPUs; not ones who are explicitly assigned housekeeping 2) we went one further in 9219565aa890 ("sched/isolation: Require a present CPU in housekeeping mask") - ensuring that housekeeping was sanity checking against present and not just possible CPUs. To be clear, this means the check added in v4.15 is doubly redundant. And more importantly, overly strict/restrictive. We care now, because the bitmap boot arg parsing now knows that a value of "N" is NR_CPUS; the size of the bitmap, but the bitmap code doesn't know anything about the subtleties of our max/possible/present CPU specifics as outlined above. So drop the check added in v4.15 (edb9382175c3) and make RCU and nohz_full both in alignment again on NR_CPUS so "N" works for both, and then they can fall back to nr_cpu_ids internally just as before. Command line: BOOT_IMAGE=/boot/bzImage nohz_full=2-N rcu_nocbs=2-N root=/dev/sda1 ro NO_HZ: Full dynticks CPUs: 2-5. rcu: Offload RCU callbacks from CPUs: 2-5. As shown above, with this change, RCU and nohz_full are in sync, even with the use of the "N" placeholder. Same result is achieved with "15". Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Paul E. McKenney <paulmck@kernel.org> Link: https://lore.kernel.org/r/20210419042659.1134916-1-paul.gortmaker@windriver.com
2020-06-15isolcpus: Affine unbound kernel threads to housekeeping cpusMarcelo Tosatti1-1/+2
This is a kernel enhancement that configures the cpu affinity of kernel threads via kernel boot option nohz_full=. When this option is specified, the cpumask is immediately applied upon kthread launch. This does not affect kernel threads that specify cpu and node. This allows CPU isolation (that is not allowing certain threads to execute on certain CPUs) without using the isolcpus=domain parameter, making it possible to enable load balancing on such CPUs during runtime (see kernel-parameters.txt). Note-1: this is based off on Wind River's patch at https://github.com/starlingx-staging/stx-integ/blob/master/kernel/kernel-std/centos/patches/affine-compute-kernel-threads.patch Difference being that this patch is limited to modifying kernel thread cpumask. Behaviour of other threads can be controlled via cgroups or sched_setaffinity. Note-2: Wind River's patch was based off Christoph Lameter's patch at https://lwn.net/Articles/565932/ with the only difference being the kernel parameter changed from kthread to kthread_cpus. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200527142909.23372-3-frederic@kernel.org
2020-04-15sched/isolation: Allow "isolcpus=" to skip unknown sub-parametersPeter Xu1-2/+19
The "isolcpus=" parameter allows sub-parameters before the cpulist is specified, and if the parser detects an unknown sub-parameters the whole parameter will be ignored. This design is incompatible with itself when new sub-parameters are added. An older kernel will not recognize the new sub-parameter and will invalidate the whole parameter so the CPU isolation will not take effect. It emits a warning: isolcpus: Error, unknown flag The better and compatible way is to allow "isolcpus=" to skip unknown sub-parameters, so that even if new sub-parameters are added an older kernel will still be able to behave as usual even if with the new sub-parameter specified on the command line. Ideally this should have been there when the first sub-parameter for "isolcpus=" was introduced. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Xu <peterx@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200403223517.406353-1-peterx@redhat.com
2020-01-22genirq, sched/isolation: Isolate from handling managed interruptsMing Lei1-0/+6
The affinity of managed interrupts is completely handled in the kernel and cannot be changed via the /proc/irq/* interfaces from user space. As the kernel tries to spread out interrupts evenly accross CPUs on x86 to prevent vector exhaustion, it can happen that a managed interrupt whose affinity mask contains both isolated and housekeeping CPUs is routed to an isolated CPU. As a consequence IO submitted on a housekeeping CPU causes interrupts on the isolated CPU. Add a new sub-parameter 'managed_irq' for 'isolcpus' and the corresponding logic in the interrupt affinity selection code. The subparameter indicates to the interrupt affinity selection logic that it should try to avoid the above scenario. This isolation is best effort and only effective if the automatically assigned interrupt mask of a device queue contains isolated and housekeeping CPUs. If housekeeping CPUs are online then such interrupts are directed to the housekeeping CPU so that IO submitted on the housekeeping CPU cannot disturb the isolated CPU. If a queue's affinity mask contains only isolated CPUs then this parameter has no effect on the interrupt routing decision, though interrupts are only happening when tasks running on those isolated CPUs submit IO. IO submitted on housekeeping CPUs has no influence on those queues. If the affinity mask contains both housekeeping and isolated CPUs, but none of the contained housekeeping CPUs is online, then the interrupt is also routed to an isolated CPU. Interrupts are only delivered when one of the isolated CPUs in the affinity mask submits IO. If one of the contained housekeeping CPUs comes online, the CPU hotplug logic migrates the interrupt automatically back to the upcoming housekeeping CPU. Depending on the type of interrupt controller, this can require that at least one interrupt is delivered to the isolated CPU in order to complete the migration. [ tglx: Removed unused parameter, added and edited comments/documentation and rephrased the changelog so it contains more details. ] Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20200120091625.17912-1-ming.lei@redhat.com
2019-07-25sched/isolation: Prefer housekeeping CPU in local nodeWanpeng Li1-2/+10
In real product setup, there will be houseeking CPUs in each nodes, it is prefer to do housekeeping from local node, fallback to global online cpumask if failed to find houseeking CPU from local node. Signed-off-by: Wanpeng Li <wanpengli@tencent.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/1561711901-4755-2-git-send-email-wanpengli@tencent.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-07-20KVM: LAPIC: Inject timer interrupt via posted interruptWanpeng Li1-0/+6
Dedicated instances are currently disturbed by unnecessary jitter due to the emulated lapic timers firing on the same pCPUs where the vCPUs reside. There is no hardware virtual timer on Intel for guest like ARM, so both programming timer in guest and the emulated timer fires incur vmexits. This patch tries to avoid vmexit when the emulated timer fires, at least in dedicated instance scenario when nohz_full is enabled. In that case, the emulated timers can be offload to the nearest busy housekeeping cpus since APICv has been found for several years in server processors. The guest timer interrupt can then be injected via posted interrupts, which are delivered by the housekeeping cpu once the emulated timer fires. The host should tuned so that vCPUs are placed on isolated physical processors, and with several pCPUs surplus for busy housekeeping. If disabled mwait/hlt/pause vmexits keep the vCPUs in non-root mode, ~3% redis performance benefit can be observed on Skylake server, and the number of external interrupt vmexits drops substantially. Without patch VM-EXIT Samples Samples% Time% Min Time Max Time Avg time EXTERNAL_INTERRUPT 42916 49.43% 39.30% 0.47us 106.09us 0.71us ( +- 1.09% ) While with patch: VM-EXIT Samples Samples% Time% Min Time Max Time Avg time EXTERNAL_INTERRUPT 6871 9.29% 2.96% 0.44us 57.88us 0.72us ( +- 4.02% ) Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Wanpeng Li <wanpengli@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-05-21treewide: Add SPDX license identifier for missed filesThomas Gleixner1-0/+1
Add SPDX license identifiers to all files which: - Have no license information of any form - Have EXPORT_.*_SYMBOL_GPL inside which was used in the initial scan/conversion to ignore the file These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-03sched/isolation: Require a present CPU in housekeeping maskNicholas Piggin1-5/+13
During housekeeping mask setup, currently a possible CPU is required. That does not guarantee the CPU would be available at boot time, so check to ensure that at least one present CPU is in the mask. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linuxppc-dev@lists.ozlabs.org Link: https://lkml.kernel.org/r/20190411033448.20842-5-npiggin@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-13sched/fair: Use non-atomic cpumask_{set,clear}_cpu()Viresh Kumar1-1/+1
The cpumasks updated here are not subject to concurrency and using atomic bitops for them is pointless and expensive. Use the non-atomic variants instead. Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vincent Guittot <vincent.guittot@linaro.org> Link: http://lkml.kernel.org/r/2e2a10f84b9049a81eef94ed6d5989447c21e34a.1549963617.git.viresh.kumar@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-12-03sched: Fix various typos in commentsIngo Molnar1-7/+7
Go over the scheduler source code and fix common typos in comments - and a typo in an actual variable name. No change in functionality intended. Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-04sched/headers: Simplify and clean up header usage in the schedulerIngo Molnar1-7/+0
Do the following cleanups and simplifications: - sched/sched.h already includes <asm/paravirt.h>, so no need to include it in sched/core.c again. - order the <linux/sched/*.h> headers alphabetically - add all <linux/sched/*.h> headers to kernel/sched/sched.h - remove all unnecessary includes from the .c files that are already included in kernel/sched/sched.h. Finally, make all scheduler .c files use a single common header: #include "sched.h" ... which now contains a union of the relied upon headers. This makes the various .c files easier to read and easier to handle. Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-03sched: Clean up and harmonize the coding style of the scheduler code baseIngo Molnar1-1/+1
A good number of small style inconsistencies have accumulated in the scheduler core, so do a pass over them to harmonize all these details: - fix speling in comments, - use curly braces for multi-line statements, - remove unnecessary parentheses from integer literals, - capitalize consistently, - remove stray newlines, - add comments where necessary, - remove invalid/unnecessary comments, - align structure definitions and other data types vertically, - add missing newlines for increased readability, - fix vertical tabulation where it's misaligned, - harmonize preprocessor conditional block labeling and vertical alignment, - remove line-breaks where they uglify the code, - add newline after local variable definitions, No change in functionality: md5: 1191fa0a890cfa8132156d2959d7e9e2 built-in.o.before.asm 1191fa0a890cfa8132156d2959d7e9e2 built-in.o.after.asm Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-21sched/isolation: Offload residual 1Hz scheduler tickFrederic Weisbecker1-0/+4
When a CPU runs in full dynticks mode, a 1Hz tick remains in order to keep the scheduler stats alive. However this residual tick is a burden for bare metal tasks that can't stand any interruption at all, or want to minimize them. The usual boot parameters "nohz_full=" or "isolcpus=nohz" will now outsource these scheduler ticks to the global workqueue so that a housekeeping CPU handles those remotely. The sched_class::task_tick() implementations have been audited and look safe to be called remotely as the target runqueue and its current task are passed in parameter and don't seem to be accessed locally. Note that in the case of using isolcpus, it's still up to the user to affine the global workqueues to the housekeeping CPUs through /sys/devices/virtual/workqueue/cpumask or domains isolation "isolcpus=nohz,domain". Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Christoph Lameter <cl@linux.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Rik van Riel <riel@redhat.com> Cc: Wanpeng Li <kernellwp@gmail.com> Link: http://lkml.kernel.org/r/1519186649-3242-6-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-21sched/isolation: Isolate workqueues when "nohz_full=" is setFrederic Weisbecker1-1/+2
As we prepare for offloading the residual 1hz scheduler ticks to workqueue, let's affine those to housekeepers so that they don't interrupt the CPUs that don't want to be disturbed. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Christoph Lameter <cl@linux.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Rik van Riel <riel@redhat.com> Cc: Wanpeng Li <kernellwp@gmail.com> Link: http://lkml.kernel.org/r/1519186649-3242-5-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-27sched/isolation: Add basic isolcpus flagsFrederic Weisbecker1-1/+25
Add flags to control NOHZ and domain isolation from "isolcpus=", in order to centralize the isolation features to a common interface. Domain isolation remains the default so not to break the existing isolcpus boot paramater behaviour. Further flags in the future may include 0hz (1hz tick offload) and timers, workqueue, RCU, kthread, watchdog, likely all merged together in a common flag ("async"?). In any case, this will have to be modifiable by cpusets. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Christoph Lameter <cl@linux.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Wanpeng Li <kernellwp@gmail.com> Link: http://lkml.kernel.org/r/1509072159-31808-12-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-27sched/isolation: Move isolcpus= handling to the housekeeping codeFrederic Weisbecker1-13/+50
We want to centralize the isolation features, to be done by the housekeeping subsystem and scheduler domain isolation is a significant part of it. No intended behaviour change, we just reuse the housekeeping cpumask and core code. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Christoph Lameter <cl@linux.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Wanpeng Li <kernellwp@gmail.com> Link: http://lkml.kernel.org/r/1509072159-31808-11-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-27sched/isolation: Handle the nohz_full= parameterFrederic Weisbecker1-12/+30
We want to centralize the isolation management, done by the housekeeping subsystem. Therefore we need to handle the nohz_full= parameter from there. Since nohz_full= so far has involved unbound timers, watchdog, RCU and tilegx NAPI isolation, we keep that default behaviour. nohz_full= will be deprecated in the future. We want to control the isolation features from the isolcpus= parameter. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Christoph Lameter <cl@linux.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Wanpeng Li <kernellwp@gmail.com> Link: http://lkml.kernel.org/r/1509072159-31808-10-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-27sched/isolation: Introduce housekeeping flagsFrederic Weisbecker1-11/+15
Before we implement isolcpus under housekeeping, we need the isolation features to be more finegrained. For example some people want NOHZ_FULL without the full scheduler isolation, others want full scheduler isolation without NOHZ_FULL. So let's cut all these isolation features piecewise, at the risk of overcutting it right now. We can still merge some flags later if they always make sense together. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Christoph Lameter <cl@linux.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Wanpeng Li <kernellwp@gmail.com> Link: http://lkml.kernel.org/r/1509072159-31808-9-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-27sched/isolation: Use its own static keyFrederic Weisbecker1-4/+9
Housekeeping code still depends on the nohz_full static key. Since we want to decouple housekeeping from NOHZ, let's create a housekeeping specific static key. It's mostly relevant for calls to is_housekeeping_cpu() from the scheduler. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Christoph Lameter <cl@linux.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Wanpeng Li <kernellwp@gmail.com> Link: http://lkml.kernel.org/r/1509072159-31808-6-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-27sched/isolation: Make the housekeeping cpumask privateFrederic Weisbecker1-1/+35
Nobody needs to access this detail. housekeeping_cpumask() already takes care of it. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Christoph Lameter <cl@linux.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Wanpeng Li <kernellwp@gmail.com> Link: http://lkml.kernel.org/r/1509072159-31808-5-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-27sched/isolation: Move housekeeping related code to its own fileFrederic Weisbecker1-0/+33
The housekeeping code is currently tied to the NOHZ code. As we are planning to make housekeeping independent from it, start with moving the relevant code to its own file. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Christoph Lameter <cl@linux.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Wanpeng Li <kernellwp@gmail.com> Link: http://lkml.kernel.org/r/1509072159-31808-2-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>