forked from Minki/linux
277edbabf6
- Redesign of cpufreq governors and the intel_pstate driver to make them use callbacks invoked by the scheduler to trigger CPU frequency evaluation instead of using per-CPU deferrable timers for that purpose (Rafael Wysocki). - Reorganization and cleanup of cpufreq governor code to make it more straightforward and fix some concurrency problems in it (Rafael Wysocki, Viresh Kumar). - Cleanup and improvements of locking in the cpufreq core (Viresh Kumar). - Assorted cleanups in the cpufreq core (Rafael Wysocki, Viresh Kumar, Eric Biggers). - intel_pstate driver updates including fixes, optimizations and a modification to make it enable enable hardware-coordinated P-state selection (HWP) by default if supported by the processor (Philippe Longepe, Srinivas Pandruvada, Rafael Wysocki, Viresh Kumar, Felipe Franciosi). - Operating Performance Points (OPP) framework updates to improve its handling of voltage regulators and device clocks and updates of the cpufreq-dt driver on top of that (Viresh Kumar, Jon Hunter). - Updates of the powernv cpufreq driver to fix initialization and cleanup problems in it and correct its worker thread handling with respect to CPU offline, new powernv_throttle tracepoint (Shilpasri Bhat). - ACPI cpufreq driver optimization and cleanup (Rafael Wysocki). - ACPICA updates including one fix for a regression introduced by previos changes in the ACPICA code (Bob Moore, Lv Zheng, David Box, Colin Ian King). - Support for installing ACPI tables from initrd (Lv Zheng). - Optimizations of the ACPI CPPC code (Prashanth Prakash, Ashwin Chaugule). - Support for _HID(ACPI0010) devices (ACPI processor containers) and ACPI processor driver cleanups (Sudeep Holla). - Support for ACPI-based enumeration of the AMBA bus (Graeme Gregory, Aleksey Makarov). - Modification of the ACPI PCI IRQ management code to make it treat 255 in the Interrupt Line register as "not connected" on x86 (as per the specification) and avoid attempts to use that value as a valid interrupt vector (Chen Fan). - ACPI APEI fixes related to resource leaks (Josh Hunt). - Removal of modularity from a few ACPI drivers (BGRT, GHES, intel_pmic_crc) that cannot be built as modules in practice (Paul Gortmaker). - PNP framework update to make it treat ACPI_RESOURCE_TYPE_SERIAL_BUS as a valid resource type (Harb Abdulhamid). - New device ID (future AMD I2C controller) in the ACPI driver for AMD SoCs (APD) and in the designware I2C driver (Xiangliang Yu). - Assorted ACPI cleanups (Colin Ian King, Kaiyen Chang, Oleg Drokin). - cpuidle menu governor optimization to avoid a square root computation in it (Rasmus Villemoes). - Fix for potential use-after-free in the generic device properties framework (Heikki Krogerus). - Updates of the generic power domains (genpd) framework including support for multiple power states of a domain, fixes and debugfs output improvements (Axel Haslam, Jon Hunter, Laurent Pinchart, Geert Uytterhoeven). - Intel RAPL power capping driver updates to reduce IPI overhead in it (Jacob Pan). - System suspend/hibernation code cleanups (Eric Biggers, Saurabh Sengar). - Year 2038 fix for the process freezer (Abhilash Jindal). - turbostat utility updates including new features (decoding of more registers and CPUID fields, sub-second intervals support, GFX MHz and RC6 printout, --out command line option), fixes (syscall jitter detection and workaround, reductioin of the number of syscalls made, fixes related to Xeon x200 processors, compiler warning fixes) and cleanups (Len Brown, Hubert Chrzaniuk, Chen Yu). / -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.22 (GNU/Linux) iQIcBAABCAAGBQJW50NXAAoJEILEb/54YlRxvr8QAIktC9+ft0y5AmU46hDcBWcK QutyWJL9X9BS6DWBJZA2qclDYFmhMfi5Fza1se0gQ9TnLB/KrBwHWLsiYoTsb1k+ nPKf214aPk+qAhkVuyB4leNWML9Qz9n9jwku/EYxWWpgtbSRf3+0ioIKZeWWc/8V JvuaOu4O+g/tkmL7QTrnGWBwhIIssAAV85QPsHkx+g68MrCj4UMMzm7z9G21SPXX bmP8yIHsczX/XnRsY0W2NSno7Vdk6ImHpDJ26IAZg28WRNPWICHgGYHvB0TTWMvb tts+yqfF7/7QLRjT/M8k9CzDBDE/DnVqoZ0fNJ+aYr7hNKF32mtAN+jH9ZB9dl/P fEFapJkPxnWyzAoVoB9Dz0rkcZkYMlbxlLWzUGpaPq0JflUUTzLk0ApSjmMn4HRO UddwCDdyHTaYThp3gn6GbOb0pIP0SdOVbI1M2QV2x/4PLcT2Ft8Np1+1RFWOeinZ Bdl9AE890big0808mqbBzw/buETwr9FjHtCdDPXpP0vJpkBLu3nIYRNb0LCt39es mWMp6dFhGgvGj3D3ahTuV3GI8hdpDkh9SObexa11RCjkTKrXcwEmFxHxLeFXwKYq alG278bo6cSChRMziS1lis+W/3tsJRN4TXUSv1PPzJHrFgptQVFRStU9ngBKP+pN WB+itPc4Fw0YHOrAFsrx =cfty -----END PGP SIGNATURE----- Merge tag 'pm+acpi-4.6-rc1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management and ACPI updates from Rafael Wysocki: "This time the majority of changes go into cpufreq and they are significant. First off, the way CPU frequency updates are triggered is different now. Instead of having to set up and manage a deferrable timer for each CPU in the system to evaluate and possibly change its frequency periodically, cpufreq governors set up callbacks to be invoked by the scheduler on a regular basis (basically on utilization updates). The "old" governors, "ondemand" and "conservative", still do all of their work in process context (although that is triggered by the scheduler now), but intel_pstate does it all in the callback invoked by the scheduler with no need for any additional asynchronous processing. Of course, this eliminates the overhead related to the management of all those timers, but also it allows the cpufreq governor code to be simplified quite a bit. On top of that, the common code and data structures used by the "ondemand" and "conservative" governors are cleaned up and made more straightforward and some long-standing and quite annoying problems are addressed. In particular, the handling of governor sysfs attributes is modified and the related locking becomes more fine grained which allows some concurrency problems to be avoided (particularly deadlocks with the core cpufreq code). In principle, the new mechanism for triggering frequency updates allows utilization information to be passed from the scheduler to cpufreq. Although the current code doesn't make use of it, in the works is a new cpufreq governor that will make decisions based on the scheduler's utilization data. That should allow the scheduler and cpufreq to work more closely together in the long run. In addition to the core and governor changes, cpufreq drivers are updated too. Fixes and optimizations go into intel_pstate, the cpufreq-dt driver is updated on top of some modification in the Operating Performance Points (OPP) framework and there are fixes and other updates in the powernv cpufreq driver. Apart from the cpufreq updates there is some new ACPICA material, including a fix for a problem introduced by previous ACPICA updates, and some less significant changes in the ACPI code, like CPPC code optimizations, ACPI processor driver cleanups and support for loading ACPI tables from initrd. Also updated are the generic power domains framework, the Intel RAPL power capping driver and the turbostat utility and we have a bunch of traditional assorted fixes and cleanups. Specifics: - Redesign of cpufreq governors and the intel_pstate driver to make them use callbacks invoked by the scheduler to trigger CPU frequency evaluation instead of using per-CPU deferrable timers for that purpose (Rafael Wysocki). - Reorganization and cleanup of cpufreq governor code to make it more straightforward and fix some concurrency problems in it (Rafael Wysocki, Viresh Kumar). - Cleanup and improvements of locking in the cpufreq core (Viresh Kumar). - Assorted cleanups in the cpufreq core (Rafael Wysocki, Viresh Kumar, Eric Biggers). - intel_pstate driver updates including fixes, optimizations and a modification to make it enable enable hardware-coordinated P-state selection (HWP) by default if supported by the processor (Philippe Longepe, Srinivas Pandruvada, Rafael Wysocki, Viresh Kumar, Felipe Franciosi). - Operating Performance Points (OPP) framework updates to improve its handling of voltage regulators and device clocks and updates of the cpufreq-dt driver on top of that (Viresh Kumar, Jon Hunter). - Updates of the powernv cpufreq driver to fix initialization and cleanup problems in it and correct its worker thread handling with respect to CPU offline, new powernv_throttle tracepoint (Shilpasri Bhat). - ACPI cpufreq driver optimization and cleanup (Rafael Wysocki). - ACPICA updates including one fix for a regression introduced by previos changes in the ACPICA code (Bob Moore, Lv Zheng, David Box, Colin Ian King). - Support for installing ACPI tables from initrd (Lv Zheng). - Optimizations of the ACPI CPPC code (Prashanth Prakash, Ashwin Chaugule). - Support for _HID(ACPI0010) devices (ACPI processor containers) and ACPI processor driver cleanups (Sudeep Holla). - Support for ACPI-based enumeration of the AMBA bus (Graeme Gregory, Aleksey Makarov). - Modification of the ACPI PCI IRQ management code to make it treat 255 in the Interrupt Line register as "not connected" on x86 (as per the specification) and avoid attempts to use that value as a valid interrupt vector (Chen Fan). - ACPI APEI fixes related to resource leaks (Josh Hunt). - Removal of modularity from a few ACPI drivers (BGRT, GHES, intel_pmic_crc) that cannot be built as modules in practice (Paul Gortmaker). - PNP framework update to make it treat ACPI_RESOURCE_TYPE_SERIAL_BUS as a valid resource type (Harb Abdulhamid). - New device ID (future AMD I2C controller) in the ACPI driver for AMD SoCs (APD) and in the designware I2C driver (Xiangliang Yu). - Assorted ACPI cleanups (Colin Ian King, Kaiyen Chang, Oleg Drokin). - cpuidle menu governor optimization to avoid a square root computation in it (Rasmus Villemoes). - Fix for potential use-after-free in the generic device properties framework (Heikki Krogerus). - Updates of the generic power domains (genpd) framework including support for multiple power states of a domain, fixes and debugfs output improvements (Axel Haslam, Jon Hunter, Laurent Pinchart, Geert Uytterhoeven). - Intel RAPL power capping driver updates to reduce IPI overhead in it (Jacob Pan). - System suspend/hibernation code cleanups (Eric Biggers, Saurabh Sengar). - Year 2038 fix for the process freezer (Abhilash Jindal). - turbostat utility updates including new features (decoding of more registers and CPUID fields, sub-second intervals support, GFX MHz and RC6 printout, --out command line option), fixes (syscall jitter detection and workaround, reductioin of the number of syscalls made, fixes related to Xeon x200 processors, compiler warning fixes) and cleanups (Len Brown, Hubert Chrzaniuk, Chen Yu)" * tag 'pm+acpi-4.6-rc1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (182 commits) tools/power turbostat: bugfix: TDP MSRs print bits fixing tools/power turbostat: correct output for MSR_NHM_SNB_PKG_CST_CFG_CTL dump tools/power turbostat: call __cpuid() instead of __get_cpuid() tools/power turbostat: indicate SMX and SGX support tools/power turbostat: detect and work around syscall jitter tools/power turbostat: show GFX%rc6 tools/power turbostat: show GFXMHz tools/power turbostat: show IRQs per CPU tools/power turbostat: make fewer systems calls tools/power turbostat: fix compiler warnings tools/power turbostat: add --out option for saving output in a file tools/power turbostat: re-name "%Busy" field to "Busy%" tools/power turbostat: Intel Xeon x200: fix turbo-ratio decoding tools/power turbostat: Intel Xeon x200: fix erroneous bclk value tools/power turbostat: allow sub-sec intervals ACPI / APEI: ERST: Fixed leaked resources in erst_init ACPI / APEI: Fix leaked resources intel_pstate: Do not skip samples partially intel_pstate: Remove freq calculation from intel_pstate_calc_busy() intel_pstate: Move intel_pstate_calc_busy() into get_target_pstate_use_performance() ...
2371 lines
54 KiB
C
2371 lines
54 KiB
C
/*
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* Real-Time Scheduling Class (mapped to the SCHED_FIFO and SCHED_RR
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* policies)
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*/
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#include "sched.h"
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#include <linux/slab.h>
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#include <linux/irq_work.h>
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int sched_rr_timeslice = RR_TIMESLICE;
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static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun);
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struct rt_bandwidth def_rt_bandwidth;
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static enum hrtimer_restart sched_rt_period_timer(struct hrtimer *timer)
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{
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struct rt_bandwidth *rt_b =
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container_of(timer, struct rt_bandwidth, rt_period_timer);
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int idle = 0;
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int overrun;
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raw_spin_lock(&rt_b->rt_runtime_lock);
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for (;;) {
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overrun = hrtimer_forward_now(timer, rt_b->rt_period);
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if (!overrun)
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break;
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raw_spin_unlock(&rt_b->rt_runtime_lock);
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idle = do_sched_rt_period_timer(rt_b, overrun);
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raw_spin_lock(&rt_b->rt_runtime_lock);
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}
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if (idle)
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rt_b->rt_period_active = 0;
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raw_spin_unlock(&rt_b->rt_runtime_lock);
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return idle ? HRTIMER_NORESTART : HRTIMER_RESTART;
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}
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void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime)
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{
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rt_b->rt_period = ns_to_ktime(period);
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rt_b->rt_runtime = runtime;
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raw_spin_lock_init(&rt_b->rt_runtime_lock);
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hrtimer_init(&rt_b->rt_period_timer,
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CLOCK_MONOTONIC, HRTIMER_MODE_REL);
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rt_b->rt_period_timer.function = sched_rt_period_timer;
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}
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static void start_rt_bandwidth(struct rt_bandwidth *rt_b)
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{
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if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF)
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return;
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raw_spin_lock(&rt_b->rt_runtime_lock);
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if (!rt_b->rt_period_active) {
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rt_b->rt_period_active = 1;
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/*
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* SCHED_DEADLINE updates the bandwidth, as a run away
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* RT task with a DL task could hog a CPU. But DL does
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* not reset the period. If a deadline task was running
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* without an RT task running, it can cause RT tasks to
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* throttle when they start up. Kick the timer right away
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* to update the period.
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*/
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hrtimer_forward_now(&rt_b->rt_period_timer, ns_to_ktime(0));
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hrtimer_start_expires(&rt_b->rt_period_timer, HRTIMER_MODE_ABS_PINNED);
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}
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raw_spin_unlock(&rt_b->rt_runtime_lock);
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}
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#if defined(CONFIG_SMP) && defined(HAVE_RT_PUSH_IPI)
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static void push_irq_work_func(struct irq_work *work);
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#endif
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void init_rt_rq(struct rt_rq *rt_rq)
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{
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struct rt_prio_array *array;
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int i;
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array = &rt_rq->active;
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for (i = 0; i < MAX_RT_PRIO; i++) {
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INIT_LIST_HEAD(array->queue + i);
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__clear_bit(i, array->bitmap);
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}
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/* delimiter for bitsearch: */
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__set_bit(MAX_RT_PRIO, array->bitmap);
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#if defined CONFIG_SMP
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rt_rq->highest_prio.curr = MAX_RT_PRIO;
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rt_rq->highest_prio.next = MAX_RT_PRIO;
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rt_rq->rt_nr_migratory = 0;
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rt_rq->overloaded = 0;
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plist_head_init(&rt_rq->pushable_tasks);
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#ifdef HAVE_RT_PUSH_IPI
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rt_rq->push_flags = 0;
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rt_rq->push_cpu = nr_cpu_ids;
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raw_spin_lock_init(&rt_rq->push_lock);
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init_irq_work(&rt_rq->push_work, push_irq_work_func);
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#endif
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#endif /* CONFIG_SMP */
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/* We start is dequeued state, because no RT tasks are queued */
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rt_rq->rt_queued = 0;
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rt_rq->rt_time = 0;
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rt_rq->rt_throttled = 0;
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rt_rq->rt_runtime = 0;
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raw_spin_lock_init(&rt_rq->rt_runtime_lock);
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}
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#ifdef CONFIG_RT_GROUP_SCHED
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static void destroy_rt_bandwidth(struct rt_bandwidth *rt_b)
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{
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hrtimer_cancel(&rt_b->rt_period_timer);
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}
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#define rt_entity_is_task(rt_se) (!(rt_se)->my_q)
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static inline struct task_struct *rt_task_of(struct sched_rt_entity *rt_se)
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{
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#ifdef CONFIG_SCHED_DEBUG
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WARN_ON_ONCE(!rt_entity_is_task(rt_se));
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#endif
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return container_of(rt_se, struct task_struct, rt);
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}
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static inline struct rq *rq_of_rt_rq(struct rt_rq *rt_rq)
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{
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return rt_rq->rq;
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}
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static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se)
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{
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return rt_se->rt_rq;
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}
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static inline struct rq *rq_of_rt_se(struct sched_rt_entity *rt_se)
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{
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struct rt_rq *rt_rq = rt_se->rt_rq;
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return rt_rq->rq;
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}
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void free_rt_sched_group(struct task_group *tg)
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{
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int i;
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if (tg->rt_se)
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destroy_rt_bandwidth(&tg->rt_bandwidth);
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for_each_possible_cpu(i) {
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if (tg->rt_rq)
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kfree(tg->rt_rq[i]);
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if (tg->rt_se)
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kfree(tg->rt_se[i]);
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}
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kfree(tg->rt_rq);
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kfree(tg->rt_se);
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}
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void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq,
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struct sched_rt_entity *rt_se, int cpu,
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struct sched_rt_entity *parent)
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{
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struct rq *rq = cpu_rq(cpu);
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rt_rq->highest_prio.curr = MAX_RT_PRIO;
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rt_rq->rt_nr_boosted = 0;
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rt_rq->rq = rq;
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rt_rq->tg = tg;
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tg->rt_rq[cpu] = rt_rq;
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tg->rt_se[cpu] = rt_se;
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if (!rt_se)
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return;
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if (!parent)
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rt_se->rt_rq = &rq->rt;
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else
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rt_se->rt_rq = parent->my_q;
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rt_se->my_q = rt_rq;
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rt_se->parent = parent;
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INIT_LIST_HEAD(&rt_se->run_list);
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}
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int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent)
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{
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struct rt_rq *rt_rq;
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struct sched_rt_entity *rt_se;
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int i;
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tg->rt_rq = kzalloc(sizeof(rt_rq) * nr_cpu_ids, GFP_KERNEL);
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if (!tg->rt_rq)
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goto err;
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tg->rt_se = kzalloc(sizeof(rt_se) * nr_cpu_ids, GFP_KERNEL);
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if (!tg->rt_se)
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goto err;
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init_rt_bandwidth(&tg->rt_bandwidth,
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ktime_to_ns(def_rt_bandwidth.rt_period), 0);
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for_each_possible_cpu(i) {
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rt_rq = kzalloc_node(sizeof(struct rt_rq),
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GFP_KERNEL, cpu_to_node(i));
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if (!rt_rq)
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goto err;
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rt_se = kzalloc_node(sizeof(struct sched_rt_entity),
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GFP_KERNEL, cpu_to_node(i));
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if (!rt_se)
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goto err_free_rq;
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init_rt_rq(rt_rq);
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rt_rq->rt_runtime = tg->rt_bandwidth.rt_runtime;
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init_tg_rt_entry(tg, rt_rq, rt_se, i, parent->rt_se[i]);
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}
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return 1;
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err_free_rq:
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kfree(rt_rq);
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err:
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return 0;
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}
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#else /* CONFIG_RT_GROUP_SCHED */
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#define rt_entity_is_task(rt_se) (1)
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static inline struct task_struct *rt_task_of(struct sched_rt_entity *rt_se)
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|
{
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return container_of(rt_se, struct task_struct, rt);
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}
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static inline struct rq *rq_of_rt_rq(struct rt_rq *rt_rq)
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|
{
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return container_of(rt_rq, struct rq, rt);
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|
}
|
|
|
|
static inline struct rq *rq_of_rt_se(struct sched_rt_entity *rt_se)
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|
{
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|
struct task_struct *p = rt_task_of(rt_se);
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|
|
return task_rq(p);
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|
}
|
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|
|
static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se)
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|
{
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|
struct rq *rq = rq_of_rt_se(rt_se);
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|
return &rq->rt;
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}
|
|
|
|
void free_rt_sched_group(struct task_group *tg) { }
|
|
|
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int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent)
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|
{
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return 1;
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}
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#endif /* CONFIG_RT_GROUP_SCHED */
|
|
|
|
#ifdef CONFIG_SMP
|
|
|
|
static void pull_rt_task(struct rq *this_rq);
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|
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static inline bool need_pull_rt_task(struct rq *rq, struct task_struct *prev)
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{
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/* Try to pull RT tasks here if we lower this rq's prio */
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return rq->rt.highest_prio.curr > prev->prio;
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}
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static inline int rt_overloaded(struct rq *rq)
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{
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return atomic_read(&rq->rd->rto_count);
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}
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static inline void rt_set_overload(struct rq *rq)
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{
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if (!rq->online)
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return;
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cpumask_set_cpu(rq->cpu, rq->rd->rto_mask);
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/*
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* Make sure the mask is visible before we set
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* the overload count. That is checked to determine
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* if we should look at the mask. It would be a shame
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* if we looked at the mask, but the mask was not
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* updated yet.
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*
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* Matched by the barrier in pull_rt_task().
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*/
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smp_wmb();
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atomic_inc(&rq->rd->rto_count);
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}
|
|
|
|
static inline void rt_clear_overload(struct rq *rq)
|
|
{
|
|
if (!rq->online)
|
|
return;
|
|
|
|
/* the order here really doesn't matter */
|
|
atomic_dec(&rq->rd->rto_count);
|
|
cpumask_clear_cpu(rq->cpu, rq->rd->rto_mask);
|
|
}
|
|
|
|
static void update_rt_migration(struct rt_rq *rt_rq)
|
|
{
|
|
if (rt_rq->rt_nr_migratory && rt_rq->rt_nr_total > 1) {
|
|
if (!rt_rq->overloaded) {
|
|
rt_set_overload(rq_of_rt_rq(rt_rq));
|
|
rt_rq->overloaded = 1;
|
|
}
|
|
} else if (rt_rq->overloaded) {
|
|
rt_clear_overload(rq_of_rt_rq(rt_rq));
|
|
rt_rq->overloaded = 0;
|
|
}
|
|
}
|
|
|
|
static void inc_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
|
|
{
|
|
struct task_struct *p;
|
|
|
|
if (!rt_entity_is_task(rt_se))
|
|
return;
|
|
|
|
p = rt_task_of(rt_se);
|
|
rt_rq = &rq_of_rt_rq(rt_rq)->rt;
|
|
|
|
rt_rq->rt_nr_total++;
|
|
if (p->nr_cpus_allowed > 1)
|
|
rt_rq->rt_nr_migratory++;
|
|
|
|
update_rt_migration(rt_rq);
|
|
}
|
|
|
|
static void dec_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
|
|
{
|
|
struct task_struct *p;
|
|
|
|
if (!rt_entity_is_task(rt_se))
|
|
return;
|
|
|
|
p = rt_task_of(rt_se);
|
|
rt_rq = &rq_of_rt_rq(rt_rq)->rt;
|
|
|
|
rt_rq->rt_nr_total--;
|
|
if (p->nr_cpus_allowed > 1)
|
|
rt_rq->rt_nr_migratory--;
|
|
|
|
update_rt_migration(rt_rq);
|
|
}
|
|
|
|
static inline int has_pushable_tasks(struct rq *rq)
|
|
{
|
|
return !plist_head_empty(&rq->rt.pushable_tasks);
|
|
}
|
|
|
|
static DEFINE_PER_CPU(struct callback_head, rt_push_head);
|
|
static DEFINE_PER_CPU(struct callback_head, rt_pull_head);
|
|
|
|
static void push_rt_tasks(struct rq *);
|
|
static void pull_rt_task(struct rq *);
|
|
|
|
static inline void queue_push_tasks(struct rq *rq)
|
|
{
|
|
if (!has_pushable_tasks(rq))
|
|
return;
|
|
|
|
queue_balance_callback(rq, &per_cpu(rt_push_head, rq->cpu), push_rt_tasks);
|
|
}
|
|
|
|
static inline void queue_pull_task(struct rq *rq)
|
|
{
|
|
queue_balance_callback(rq, &per_cpu(rt_pull_head, rq->cpu), pull_rt_task);
|
|
}
|
|
|
|
static void enqueue_pushable_task(struct rq *rq, struct task_struct *p)
|
|
{
|
|
plist_del(&p->pushable_tasks, &rq->rt.pushable_tasks);
|
|
plist_node_init(&p->pushable_tasks, p->prio);
|
|
plist_add(&p->pushable_tasks, &rq->rt.pushable_tasks);
|
|
|
|
/* Update the highest prio pushable task */
|
|
if (p->prio < rq->rt.highest_prio.next)
|
|
rq->rt.highest_prio.next = p->prio;
|
|
}
|
|
|
|
static void dequeue_pushable_task(struct rq *rq, struct task_struct *p)
|
|
{
|
|
plist_del(&p->pushable_tasks, &rq->rt.pushable_tasks);
|
|
|
|
/* Update the new highest prio pushable task */
|
|
if (has_pushable_tasks(rq)) {
|
|
p = plist_first_entry(&rq->rt.pushable_tasks,
|
|
struct task_struct, pushable_tasks);
|
|
rq->rt.highest_prio.next = p->prio;
|
|
} else
|
|
rq->rt.highest_prio.next = MAX_RT_PRIO;
|
|
}
|
|
|
|
#else
|
|
|
|
static inline void enqueue_pushable_task(struct rq *rq, struct task_struct *p)
|
|
{
|
|
}
|
|
|
|
static inline void dequeue_pushable_task(struct rq *rq, struct task_struct *p)
|
|
{
|
|
}
|
|
|
|
static inline
|
|
void inc_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
|
|
{
|
|
}
|
|
|
|
static inline
|
|
void dec_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
|
|
{
|
|
}
|
|
|
|
static inline bool need_pull_rt_task(struct rq *rq, struct task_struct *prev)
|
|
{
|
|
return false;
|
|
}
|
|
|
|
static inline void pull_rt_task(struct rq *this_rq)
|
|
{
|
|
}
|
|
|
|
static inline void queue_push_tasks(struct rq *rq)
|
|
{
|
|
}
|
|
#endif /* CONFIG_SMP */
|
|
|
|
static void enqueue_top_rt_rq(struct rt_rq *rt_rq);
|
|
static void dequeue_top_rt_rq(struct rt_rq *rt_rq);
|
|
|
|
static inline int on_rt_rq(struct sched_rt_entity *rt_se)
|
|
{
|
|
return rt_se->on_rq;
|
|
}
|
|
|
|
#ifdef CONFIG_RT_GROUP_SCHED
|
|
|
|
static inline u64 sched_rt_runtime(struct rt_rq *rt_rq)
|
|
{
|
|
if (!rt_rq->tg)
|
|
return RUNTIME_INF;
|
|
|
|
return rt_rq->rt_runtime;
|
|
}
|
|
|
|
static inline u64 sched_rt_period(struct rt_rq *rt_rq)
|
|
{
|
|
return ktime_to_ns(rt_rq->tg->rt_bandwidth.rt_period);
|
|
}
|
|
|
|
typedef struct task_group *rt_rq_iter_t;
|
|
|
|
static inline struct task_group *next_task_group(struct task_group *tg)
|
|
{
|
|
do {
|
|
tg = list_entry_rcu(tg->list.next,
|
|
typeof(struct task_group), list);
|
|
} while (&tg->list != &task_groups && task_group_is_autogroup(tg));
|
|
|
|
if (&tg->list == &task_groups)
|
|
tg = NULL;
|
|
|
|
return tg;
|
|
}
|
|
|
|
#define for_each_rt_rq(rt_rq, iter, rq) \
|
|
for (iter = container_of(&task_groups, typeof(*iter), list); \
|
|
(iter = next_task_group(iter)) && \
|
|
(rt_rq = iter->rt_rq[cpu_of(rq)]);)
|
|
|
|
#define for_each_sched_rt_entity(rt_se) \
|
|
for (; rt_se; rt_se = rt_se->parent)
|
|
|
|
static inline struct rt_rq *group_rt_rq(struct sched_rt_entity *rt_se)
|
|
{
|
|
return rt_se->my_q;
|
|
}
|
|
|
|
static void enqueue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags);
|
|
static void dequeue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags);
|
|
|
|
static void sched_rt_rq_enqueue(struct rt_rq *rt_rq)
|
|
{
|
|
struct task_struct *curr = rq_of_rt_rq(rt_rq)->curr;
|
|
struct rq *rq = rq_of_rt_rq(rt_rq);
|
|
struct sched_rt_entity *rt_se;
|
|
|
|
int cpu = cpu_of(rq);
|
|
|
|
rt_se = rt_rq->tg->rt_se[cpu];
|
|
|
|
if (rt_rq->rt_nr_running) {
|
|
if (!rt_se)
|
|
enqueue_top_rt_rq(rt_rq);
|
|
else if (!on_rt_rq(rt_se))
|
|
enqueue_rt_entity(rt_se, 0);
|
|
|
|
if (rt_rq->highest_prio.curr < curr->prio)
|
|
resched_curr(rq);
|
|
}
|
|
}
|
|
|
|
static void sched_rt_rq_dequeue(struct rt_rq *rt_rq)
|
|
{
|
|
struct sched_rt_entity *rt_se;
|
|
int cpu = cpu_of(rq_of_rt_rq(rt_rq));
|
|
|
|
rt_se = rt_rq->tg->rt_se[cpu];
|
|
|
|
if (!rt_se)
|
|
dequeue_top_rt_rq(rt_rq);
|
|
else if (on_rt_rq(rt_se))
|
|
dequeue_rt_entity(rt_se, 0);
|
|
}
|
|
|
|
static inline int rt_rq_throttled(struct rt_rq *rt_rq)
|
|
{
|
|
return rt_rq->rt_throttled && !rt_rq->rt_nr_boosted;
|
|
}
|
|
|
|
static int rt_se_boosted(struct sched_rt_entity *rt_se)
|
|
{
|
|
struct rt_rq *rt_rq = group_rt_rq(rt_se);
|
|
struct task_struct *p;
|
|
|
|
if (rt_rq)
|
|
return !!rt_rq->rt_nr_boosted;
|
|
|
|
p = rt_task_of(rt_se);
|
|
return p->prio != p->normal_prio;
|
|
}
|
|
|
|
#ifdef CONFIG_SMP
|
|
static inline const struct cpumask *sched_rt_period_mask(void)
|
|
{
|
|
return this_rq()->rd->span;
|
|
}
|
|
#else
|
|
static inline const struct cpumask *sched_rt_period_mask(void)
|
|
{
|
|
return cpu_online_mask;
|
|
}
|
|
#endif
|
|
|
|
static inline
|
|
struct rt_rq *sched_rt_period_rt_rq(struct rt_bandwidth *rt_b, int cpu)
|
|
{
|
|
return container_of(rt_b, struct task_group, rt_bandwidth)->rt_rq[cpu];
|
|
}
|
|
|
|
static inline struct rt_bandwidth *sched_rt_bandwidth(struct rt_rq *rt_rq)
|
|
{
|
|
return &rt_rq->tg->rt_bandwidth;
|
|
}
|
|
|
|
#else /* !CONFIG_RT_GROUP_SCHED */
|
|
|
|
static inline u64 sched_rt_runtime(struct rt_rq *rt_rq)
|
|
{
|
|
return rt_rq->rt_runtime;
|
|
}
|
|
|
|
static inline u64 sched_rt_period(struct rt_rq *rt_rq)
|
|
{
|
|
return ktime_to_ns(def_rt_bandwidth.rt_period);
|
|
}
|
|
|
|
typedef struct rt_rq *rt_rq_iter_t;
|
|
|
|
#define for_each_rt_rq(rt_rq, iter, rq) \
|
|
for ((void) iter, rt_rq = &rq->rt; rt_rq; rt_rq = NULL)
|
|
|
|
#define for_each_sched_rt_entity(rt_se) \
|
|
for (; rt_se; rt_se = NULL)
|
|
|
|
static inline struct rt_rq *group_rt_rq(struct sched_rt_entity *rt_se)
|
|
{
|
|
return NULL;
|
|
}
|
|
|
|
static inline void sched_rt_rq_enqueue(struct rt_rq *rt_rq)
|
|
{
|
|
struct rq *rq = rq_of_rt_rq(rt_rq);
|
|
|
|
if (!rt_rq->rt_nr_running)
|
|
return;
|
|
|
|
enqueue_top_rt_rq(rt_rq);
|
|
resched_curr(rq);
|
|
}
|
|
|
|
static inline void sched_rt_rq_dequeue(struct rt_rq *rt_rq)
|
|
{
|
|
dequeue_top_rt_rq(rt_rq);
|
|
}
|
|
|
|
static inline int rt_rq_throttled(struct rt_rq *rt_rq)
|
|
{
|
|
return rt_rq->rt_throttled;
|
|
}
|
|
|
|
static inline const struct cpumask *sched_rt_period_mask(void)
|
|
{
|
|
return cpu_online_mask;
|
|
}
|
|
|
|
static inline
|
|
struct rt_rq *sched_rt_period_rt_rq(struct rt_bandwidth *rt_b, int cpu)
|
|
{
|
|
return &cpu_rq(cpu)->rt;
|
|
}
|
|
|
|
static inline struct rt_bandwidth *sched_rt_bandwidth(struct rt_rq *rt_rq)
|
|
{
|
|
return &def_rt_bandwidth;
|
|
}
|
|
|
|
#endif /* CONFIG_RT_GROUP_SCHED */
|
|
|
|
bool sched_rt_bandwidth_account(struct rt_rq *rt_rq)
|
|
{
|
|
struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq);
|
|
|
|
return (hrtimer_active(&rt_b->rt_period_timer) ||
|
|
rt_rq->rt_time < rt_b->rt_runtime);
|
|
}
|
|
|
|
#ifdef CONFIG_SMP
|
|
/*
|
|
* We ran out of runtime, see if we can borrow some from our neighbours.
|
|
*/
|
|
static void do_balance_runtime(struct rt_rq *rt_rq)
|
|
{
|
|
struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq);
|
|
struct root_domain *rd = rq_of_rt_rq(rt_rq)->rd;
|
|
int i, weight;
|
|
u64 rt_period;
|
|
|
|
weight = cpumask_weight(rd->span);
|
|
|
|
raw_spin_lock(&rt_b->rt_runtime_lock);
|
|
rt_period = ktime_to_ns(rt_b->rt_period);
|
|
for_each_cpu(i, rd->span) {
|
|
struct rt_rq *iter = sched_rt_period_rt_rq(rt_b, i);
|
|
s64 diff;
|
|
|
|
if (iter == rt_rq)
|
|
continue;
|
|
|
|
raw_spin_lock(&iter->rt_runtime_lock);
|
|
/*
|
|
* Either all rqs have inf runtime and there's nothing to steal
|
|
* or __disable_runtime() below sets a specific rq to inf to
|
|
* indicate its been disabled and disalow stealing.
|
|
*/
|
|
if (iter->rt_runtime == RUNTIME_INF)
|
|
goto next;
|
|
|
|
/*
|
|
* From runqueues with spare time, take 1/n part of their
|
|
* spare time, but no more than our period.
|
|
*/
|
|
diff = iter->rt_runtime - iter->rt_time;
|
|
if (diff > 0) {
|
|
diff = div_u64((u64)diff, weight);
|
|
if (rt_rq->rt_runtime + diff > rt_period)
|
|
diff = rt_period - rt_rq->rt_runtime;
|
|
iter->rt_runtime -= diff;
|
|
rt_rq->rt_runtime += diff;
|
|
if (rt_rq->rt_runtime == rt_period) {
|
|
raw_spin_unlock(&iter->rt_runtime_lock);
|
|
break;
|
|
}
|
|
}
|
|
next:
|
|
raw_spin_unlock(&iter->rt_runtime_lock);
|
|
}
|
|
raw_spin_unlock(&rt_b->rt_runtime_lock);
|
|
}
|
|
|
|
/*
|
|
* Ensure this RQ takes back all the runtime it lend to its neighbours.
|
|
*/
|
|
static void __disable_runtime(struct rq *rq)
|
|
{
|
|
struct root_domain *rd = rq->rd;
|
|
rt_rq_iter_t iter;
|
|
struct rt_rq *rt_rq;
|
|
|
|
if (unlikely(!scheduler_running))
|
|
return;
|
|
|
|
for_each_rt_rq(rt_rq, iter, rq) {
|
|
struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq);
|
|
s64 want;
|
|
int i;
|
|
|
|
raw_spin_lock(&rt_b->rt_runtime_lock);
|
|
raw_spin_lock(&rt_rq->rt_runtime_lock);
|
|
/*
|
|
* Either we're all inf and nobody needs to borrow, or we're
|
|
* already disabled and thus have nothing to do, or we have
|
|
* exactly the right amount of runtime to take out.
|
|
*/
|
|
if (rt_rq->rt_runtime == RUNTIME_INF ||
|
|
rt_rq->rt_runtime == rt_b->rt_runtime)
|
|
goto balanced;
|
|
raw_spin_unlock(&rt_rq->rt_runtime_lock);
|
|
|
|
/*
|
|
* Calculate the difference between what we started out with
|
|
* and what we current have, that's the amount of runtime
|
|
* we lend and now have to reclaim.
|
|
*/
|
|
want = rt_b->rt_runtime - rt_rq->rt_runtime;
|
|
|
|
/*
|
|
* Greedy reclaim, take back as much as we can.
|
|
*/
|
|
for_each_cpu(i, rd->span) {
|
|
struct rt_rq *iter = sched_rt_period_rt_rq(rt_b, i);
|
|
s64 diff;
|
|
|
|
/*
|
|
* Can't reclaim from ourselves or disabled runqueues.
|
|
*/
|
|
if (iter == rt_rq || iter->rt_runtime == RUNTIME_INF)
|
|
continue;
|
|
|
|
raw_spin_lock(&iter->rt_runtime_lock);
|
|
if (want > 0) {
|
|
diff = min_t(s64, iter->rt_runtime, want);
|
|
iter->rt_runtime -= diff;
|
|
want -= diff;
|
|
} else {
|
|
iter->rt_runtime -= want;
|
|
want -= want;
|
|
}
|
|
raw_spin_unlock(&iter->rt_runtime_lock);
|
|
|
|
if (!want)
|
|
break;
|
|
}
|
|
|
|
raw_spin_lock(&rt_rq->rt_runtime_lock);
|
|
/*
|
|
* We cannot be left wanting - that would mean some runtime
|
|
* leaked out of the system.
|
|
*/
|
|
BUG_ON(want);
|
|
balanced:
|
|
/*
|
|
* Disable all the borrow logic by pretending we have inf
|
|
* runtime - in which case borrowing doesn't make sense.
|
|
*/
|
|
rt_rq->rt_runtime = RUNTIME_INF;
|
|
rt_rq->rt_throttled = 0;
|
|
raw_spin_unlock(&rt_rq->rt_runtime_lock);
|
|
raw_spin_unlock(&rt_b->rt_runtime_lock);
|
|
|
|
/* Make rt_rq available for pick_next_task() */
|
|
sched_rt_rq_enqueue(rt_rq);
|
|
}
|
|
}
|
|
|
|
static void __enable_runtime(struct rq *rq)
|
|
{
|
|
rt_rq_iter_t iter;
|
|
struct rt_rq *rt_rq;
|
|
|
|
if (unlikely(!scheduler_running))
|
|
return;
|
|
|
|
/*
|
|
* Reset each runqueue's bandwidth settings
|
|
*/
|
|
for_each_rt_rq(rt_rq, iter, rq) {
|
|
struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq);
|
|
|
|
raw_spin_lock(&rt_b->rt_runtime_lock);
|
|
raw_spin_lock(&rt_rq->rt_runtime_lock);
|
|
rt_rq->rt_runtime = rt_b->rt_runtime;
|
|
rt_rq->rt_time = 0;
|
|
rt_rq->rt_throttled = 0;
|
|
raw_spin_unlock(&rt_rq->rt_runtime_lock);
|
|
raw_spin_unlock(&rt_b->rt_runtime_lock);
|
|
}
|
|
}
|
|
|
|
static void balance_runtime(struct rt_rq *rt_rq)
|
|
{
|
|
if (!sched_feat(RT_RUNTIME_SHARE))
|
|
return;
|
|
|
|
if (rt_rq->rt_time > rt_rq->rt_runtime) {
|
|
raw_spin_unlock(&rt_rq->rt_runtime_lock);
|
|
do_balance_runtime(rt_rq);
|
|
raw_spin_lock(&rt_rq->rt_runtime_lock);
|
|
}
|
|
}
|
|
#else /* !CONFIG_SMP */
|
|
static inline void balance_runtime(struct rt_rq *rt_rq) {}
|
|
#endif /* CONFIG_SMP */
|
|
|
|
static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun)
|
|
{
|
|
int i, idle = 1, throttled = 0;
|
|
const struct cpumask *span;
|
|
|
|
span = sched_rt_period_mask();
|
|
#ifdef CONFIG_RT_GROUP_SCHED
|
|
/*
|
|
* FIXME: isolated CPUs should really leave the root task group,
|
|
* whether they are isolcpus or were isolated via cpusets, lest
|
|
* the timer run on a CPU which does not service all runqueues,
|
|
* potentially leaving other CPUs indefinitely throttled. If
|
|
* isolation is really required, the user will turn the throttle
|
|
* off to kill the perturbations it causes anyway. Meanwhile,
|
|
* this maintains functionality for boot and/or troubleshooting.
|
|
*/
|
|
if (rt_b == &root_task_group.rt_bandwidth)
|
|
span = cpu_online_mask;
|
|
#endif
|
|
for_each_cpu(i, span) {
|
|
int enqueue = 0;
|
|
struct rt_rq *rt_rq = sched_rt_period_rt_rq(rt_b, i);
|
|
struct rq *rq = rq_of_rt_rq(rt_rq);
|
|
|
|
raw_spin_lock(&rq->lock);
|
|
if (rt_rq->rt_time) {
|
|
u64 runtime;
|
|
|
|
raw_spin_lock(&rt_rq->rt_runtime_lock);
|
|
if (rt_rq->rt_throttled)
|
|
balance_runtime(rt_rq);
|
|
runtime = rt_rq->rt_runtime;
|
|
rt_rq->rt_time -= min(rt_rq->rt_time, overrun*runtime);
|
|
if (rt_rq->rt_throttled && rt_rq->rt_time < runtime) {
|
|
rt_rq->rt_throttled = 0;
|
|
enqueue = 1;
|
|
|
|
/*
|
|
* When we're idle and a woken (rt) task is
|
|
* throttled check_preempt_curr() will set
|
|
* skip_update and the time between the wakeup
|
|
* and this unthrottle will get accounted as
|
|
* 'runtime'.
|
|
*/
|
|
if (rt_rq->rt_nr_running && rq->curr == rq->idle)
|
|
rq_clock_skip_update(rq, false);
|
|
}
|
|
if (rt_rq->rt_time || rt_rq->rt_nr_running)
|
|
idle = 0;
|
|
raw_spin_unlock(&rt_rq->rt_runtime_lock);
|
|
} else if (rt_rq->rt_nr_running) {
|
|
idle = 0;
|
|
if (!rt_rq_throttled(rt_rq))
|
|
enqueue = 1;
|
|
}
|
|
if (rt_rq->rt_throttled)
|
|
throttled = 1;
|
|
|
|
if (enqueue)
|
|
sched_rt_rq_enqueue(rt_rq);
|
|
raw_spin_unlock(&rq->lock);
|
|
}
|
|
|
|
if (!throttled && (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF))
|
|
return 1;
|
|
|
|
return idle;
|
|
}
|
|
|
|
static inline int rt_se_prio(struct sched_rt_entity *rt_se)
|
|
{
|
|
#ifdef CONFIG_RT_GROUP_SCHED
|
|
struct rt_rq *rt_rq = group_rt_rq(rt_se);
|
|
|
|
if (rt_rq)
|
|
return rt_rq->highest_prio.curr;
|
|
#endif
|
|
|
|
return rt_task_of(rt_se)->prio;
|
|
}
|
|
|
|
static int sched_rt_runtime_exceeded(struct rt_rq *rt_rq)
|
|
{
|
|
u64 runtime = sched_rt_runtime(rt_rq);
|
|
|
|
if (rt_rq->rt_throttled)
|
|
return rt_rq_throttled(rt_rq);
|
|
|
|
if (runtime >= sched_rt_period(rt_rq))
|
|
return 0;
|
|
|
|
balance_runtime(rt_rq);
|
|
runtime = sched_rt_runtime(rt_rq);
|
|
if (runtime == RUNTIME_INF)
|
|
return 0;
|
|
|
|
if (rt_rq->rt_time > runtime) {
|
|
struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq);
|
|
|
|
/*
|
|
* Don't actually throttle groups that have no runtime assigned
|
|
* but accrue some time due to boosting.
|
|
*/
|
|
if (likely(rt_b->rt_runtime)) {
|
|
rt_rq->rt_throttled = 1;
|
|
printk_deferred_once("sched: RT throttling activated\n");
|
|
} else {
|
|
/*
|
|
* In case we did anyway, make it go away,
|
|
* replenishment is a joke, since it will replenish us
|
|
* with exactly 0 ns.
|
|
*/
|
|
rt_rq->rt_time = 0;
|
|
}
|
|
|
|
if (rt_rq_throttled(rt_rq)) {
|
|
sched_rt_rq_dequeue(rt_rq);
|
|
return 1;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Update the current task's runtime statistics. Skip current tasks that
|
|
* are not in our scheduling class.
|
|
*/
|
|
static void update_curr_rt(struct rq *rq)
|
|
{
|
|
struct task_struct *curr = rq->curr;
|
|
struct sched_rt_entity *rt_se = &curr->rt;
|
|
u64 delta_exec;
|
|
|
|
if (curr->sched_class != &rt_sched_class)
|
|
return;
|
|
|
|
/* Kick cpufreq (see the comment in linux/cpufreq.h). */
|
|
if (cpu_of(rq) == smp_processor_id())
|
|
cpufreq_trigger_update(rq_clock(rq));
|
|
|
|
delta_exec = rq_clock_task(rq) - curr->se.exec_start;
|
|
if (unlikely((s64)delta_exec <= 0))
|
|
return;
|
|
|
|
schedstat_set(curr->se.statistics.exec_max,
|
|
max(curr->se.statistics.exec_max, delta_exec));
|
|
|
|
curr->se.sum_exec_runtime += delta_exec;
|
|
account_group_exec_runtime(curr, delta_exec);
|
|
|
|
curr->se.exec_start = rq_clock_task(rq);
|
|
cpuacct_charge(curr, delta_exec);
|
|
|
|
sched_rt_avg_update(rq, delta_exec);
|
|
|
|
if (!rt_bandwidth_enabled())
|
|
return;
|
|
|
|
for_each_sched_rt_entity(rt_se) {
|
|
struct rt_rq *rt_rq = rt_rq_of_se(rt_se);
|
|
|
|
if (sched_rt_runtime(rt_rq) != RUNTIME_INF) {
|
|
raw_spin_lock(&rt_rq->rt_runtime_lock);
|
|
rt_rq->rt_time += delta_exec;
|
|
if (sched_rt_runtime_exceeded(rt_rq))
|
|
resched_curr(rq);
|
|
raw_spin_unlock(&rt_rq->rt_runtime_lock);
|
|
}
|
|
}
|
|
}
|
|
|
|
static void
|
|
dequeue_top_rt_rq(struct rt_rq *rt_rq)
|
|
{
|
|
struct rq *rq = rq_of_rt_rq(rt_rq);
|
|
|
|
BUG_ON(&rq->rt != rt_rq);
|
|
|
|
if (!rt_rq->rt_queued)
|
|
return;
|
|
|
|
BUG_ON(!rq->nr_running);
|
|
|
|
sub_nr_running(rq, rt_rq->rt_nr_running);
|
|
rt_rq->rt_queued = 0;
|
|
}
|
|
|
|
static void
|
|
enqueue_top_rt_rq(struct rt_rq *rt_rq)
|
|
{
|
|
struct rq *rq = rq_of_rt_rq(rt_rq);
|
|
|
|
BUG_ON(&rq->rt != rt_rq);
|
|
|
|
if (rt_rq->rt_queued)
|
|
return;
|
|
if (rt_rq_throttled(rt_rq) || !rt_rq->rt_nr_running)
|
|
return;
|
|
|
|
add_nr_running(rq, rt_rq->rt_nr_running);
|
|
rt_rq->rt_queued = 1;
|
|
}
|
|
|
|
#if defined CONFIG_SMP
|
|
|
|
static void
|
|
inc_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio)
|
|
{
|
|
struct rq *rq = rq_of_rt_rq(rt_rq);
|
|
|
|
#ifdef CONFIG_RT_GROUP_SCHED
|
|
/*
|
|
* Change rq's cpupri only if rt_rq is the top queue.
|
|
*/
|
|
if (&rq->rt != rt_rq)
|
|
return;
|
|
#endif
|
|
if (rq->online && prio < prev_prio)
|
|
cpupri_set(&rq->rd->cpupri, rq->cpu, prio);
|
|
}
|
|
|
|
static void
|
|
dec_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio)
|
|
{
|
|
struct rq *rq = rq_of_rt_rq(rt_rq);
|
|
|
|
#ifdef CONFIG_RT_GROUP_SCHED
|
|
/*
|
|
* Change rq's cpupri only if rt_rq is the top queue.
|
|
*/
|
|
if (&rq->rt != rt_rq)
|
|
return;
|
|
#endif
|
|
if (rq->online && rt_rq->highest_prio.curr != prev_prio)
|
|
cpupri_set(&rq->rd->cpupri, rq->cpu, rt_rq->highest_prio.curr);
|
|
}
|
|
|
|
#else /* CONFIG_SMP */
|
|
|
|
static inline
|
|
void inc_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) {}
|
|
static inline
|
|
void dec_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) {}
|
|
|
|
#endif /* CONFIG_SMP */
|
|
|
|
#if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED
|
|
static void
|
|
inc_rt_prio(struct rt_rq *rt_rq, int prio)
|
|
{
|
|
int prev_prio = rt_rq->highest_prio.curr;
|
|
|
|
if (prio < prev_prio)
|
|
rt_rq->highest_prio.curr = prio;
|
|
|
|
inc_rt_prio_smp(rt_rq, prio, prev_prio);
|
|
}
|
|
|
|
static void
|
|
dec_rt_prio(struct rt_rq *rt_rq, int prio)
|
|
{
|
|
int prev_prio = rt_rq->highest_prio.curr;
|
|
|
|
if (rt_rq->rt_nr_running) {
|
|
|
|
WARN_ON(prio < prev_prio);
|
|
|
|
/*
|
|
* This may have been our highest task, and therefore
|
|
* we may have some recomputation to do
|
|
*/
|
|
if (prio == prev_prio) {
|
|
struct rt_prio_array *array = &rt_rq->active;
|
|
|
|
rt_rq->highest_prio.curr =
|
|
sched_find_first_bit(array->bitmap);
|
|
}
|
|
|
|
} else
|
|
rt_rq->highest_prio.curr = MAX_RT_PRIO;
|
|
|
|
dec_rt_prio_smp(rt_rq, prio, prev_prio);
|
|
}
|
|
|
|
#else
|
|
|
|
static inline void inc_rt_prio(struct rt_rq *rt_rq, int prio) {}
|
|
static inline void dec_rt_prio(struct rt_rq *rt_rq, int prio) {}
|
|
|
|
#endif /* CONFIG_SMP || CONFIG_RT_GROUP_SCHED */
|
|
|
|
#ifdef CONFIG_RT_GROUP_SCHED
|
|
|
|
static void
|
|
inc_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
|
|
{
|
|
if (rt_se_boosted(rt_se))
|
|
rt_rq->rt_nr_boosted++;
|
|
|
|
if (rt_rq->tg)
|
|
start_rt_bandwidth(&rt_rq->tg->rt_bandwidth);
|
|
}
|
|
|
|
static void
|
|
dec_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
|
|
{
|
|
if (rt_se_boosted(rt_se))
|
|
rt_rq->rt_nr_boosted--;
|
|
|
|
WARN_ON(!rt_rq->rt_nr_running && rt_rq->rt_nr_boosted);
|
|
}
|
|
|
|
#else /* CONFIG_RT_GROUP_SCHED */
|
|
|
|
static void
|
|
inc_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
|
|
{
|
|
start_rt_bandwidth(&def_rt_bandwidth);
|
|
}
|
|
|
|
static inline
|
|
void dec_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) {}
|
|
|
|
#endif /* CONFIG_RT_GROUP_SCHED */
|
|
|
|
static inline
|
|
unsigned int rt_se_nr_running(struct sched_rt_entity *rt_se)
|
|
{
|
|
struct rt_rq *group_rq = group_rt_rq(rt_se);
|
|
|
|
if (group_rq)
|
|
return group_rq->rt_nr_running;
|
|
else
|
|
return 1;
|
|
}
|
|
|
|
static inline
|
|
unsigned int rt_se_rr_nr_running(struct sched_rt_entity *rt_se)
|
|
{
|
|
struct rt_rq *group_rq = group_rt_rq(rt_se);
|
|
struct task_struct *tsk;
|
|
|
|
if (group_rq)
|
|
return group_rq->rr_nr_running;
|
|
|
|
tsk = rt_task_of(rt_se);
|
|
|
|
return (tsk->policy == SCHED_RR) ? 1 : 0;
|
|
}
|
|
|
|
static inline
|
|
void inc_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
|
|
{
|
|
int prio = rt_se_prio(rt_se);
|
|
|
|
WARN_ON(!rt_prio(prio));
|
|
rt_rq->rt_nr_running += rt_se_nr_running(rt_se);
|
|
rt_rq->rr_nr_running += rt_se_rr_nr_running(rt_se);
|
|
|
|
inc_rt_prio(rt_rq, prio);
|
|
inc_rt_migration(rt_se, rt_rq);
|
|
inc_rt_group(rt_se, rt_rq);
|
|
}
|
|
|
|
static inline
|
|
void dec_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
|
|
{
|
|
WARN_ON(!rt_prio(rt_se_prio(rt_se)));
|
|
WARN_ON(!rt_rq->rt_nr_running);
|
|
rt_rq->rt_nr_running -= rt_se_nr_running(rt_se);
|
|
rt_rq->rr_nr_running -= rt_se_rr_nr_running(rt_se);
|
|
|
|
dec_rt_prio(rt_rq, rt_se_prio(rt_se));
|
|
dec_rt_migration(rt_se, rt_rq);
|
|
dec_rt_group(rt_se, rt_rq);
|
|
}
|
|
|
|
/*
|
|
* Change rt_se->run_list location unless SAVE && !MOVE
|
|
*
|
|
* assumes ENQUEUE/DEQUEUE flags match
|
|
*/
|
|
static inline bool move_entity(unsigned int flags)
|
|
{
|
|
if ((flags & (DEQUEUE_SAVE | DEQUEUE_MOVE)) == DEQUEUE_SAVE)
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
|
|
static void __delist_rt_entity(struct sched_rt_entity *rt_se, struct rt_prio_array *array)
|
|
{
|
|
list_del_init(&rt_se->run_list);
|
|
|
|
if (list_empty(array->queue + rt_se_prio(rt_se)))
|
|
__clear_bit(rt_se_prio(rt_se), array->bitmap);
|
|
|
|
rt_se->on_list = 0;
|
|
}
|
|
|
|
static void __enqueue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags)
|
|
{
|
|
struct rt_rq *rt_rq = rt_rq_of_se(rt_se);
|
|
struct rt_prio_array *array = &rt_rq->active;
|
|
struct rt_rq *group_rq = group_rt_rq(rt_se);
|
|
struct list_head *queue = array->queue + rt_se_prio(rt_se);
|
|
|
|
/*
|
|
* Don't enqueue the group if its throttled, or when empty.
|
|
* The latter is a consequence of the former when a child group
|
|
* get throttled and the current group doesn't have any other
|
|
* active members.
|
|
*/
|
|
if (group_rq && (rt_rq_throttled(group_rq) || !group_rq->rt_nr_running)) {
|
|
if (rt_se->on_list)
|
|
__delist_rt_entity(rt_se, array);
|
|
return;
|
|
}
|
|
|
|
if (move_entity(flags)) {
|
|
WARN_ON_ONCE(rt_se->on_list);
|
|
if (flags & ENQUEUE_HEAD)
|
|
list_add(&rt_se->run_list, queue);
|
|
else
|
|
list_add_tail(&rt_se->run_list, queue);
|
|
|
|
__set_bit(rt_se_prio(rt_se), array->bitmap);
|
|
rt_se->on_list = 1;
|
|
}
|
|
rt_se->on_rq = 1;
|
|
|
|
inc_rt_tasks(rt_se, rt_rq);
|
|
}
|
|
|
|
static void __dequeue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags)
|
|
{
|
|
struct rt_rq *rt_rq = rt_rq_of_se(rt_se);
|
|
struct rt_prio_array *array = &rt_rq->active;
|
|
|
|
if (move_entity(flags)) {
|
|
WARN_ON_ONCE(!rt_se->on_list);
|
|
__delist_rt_entity(rt_se, array);
|
|
}
|
|
rt_se->on_rq = 0;
|
|
|
|
dec_rt_tasks(rt_se, rt_rq);
|
|
}
|
|
|
|
/*
|
|
* Because the prio of an upper entry depends on the lower
|
|
* entries, we must remove entries top - down.
|
|
*/
|
|
static void dequeue_rt_stack(struct sched_rt_entity *rt_se, unsigned int flags)
|
|
{
|
|
struct sched_rt_entity *back = NULL;
|
|
|
|
for_each_sched_rt_entity(rt_se) {
|
|
rt_se->back = back;
|
|
back = rt_se;
|
|
}
|
|
|
|
dequeue_top_rt_rq(rt_rq_of_se(back));
|
|
|
|
for (rt_se = back; rt_se; rt_se = rt_se->back) {
|
|
if (on_rt_rq(rt_se))
|
|
__dequeue_rt_entity(rt_se, flags);
|
|
}
|
|
}
|
|
|
|
static void enqueue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags)
|
|
{
|
|
struct rq *rq = rq_of_rt_se(rt_se);
|
|
|
|
dequeue_rt_stack(rt_se, flags);
|
|
for_each_sched_rt_entity(rt_se)
|
|
__enqueue_rt_entity(rt_se, flags);
|
|
enqueue_top_rt_rq(&rq->rt);
|
|
}
|
|
|
|
static void dequeue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags)
|
|
{
|
|
struct rq *rq = rq_of_rt_se(rt_se);
|
|
|
|
dequeue_rt_stack(rt_se, flags);
|
|
|
|
for_each_sched_rt_entity(rt_se) {
|
|
struct rt_rq *rt_rq = group_rt_rq(rt_se);
|
|
|
|
if (rt_rq && rt_rq->rt_nr_running)
|
|
__enqueue_rt_entity(rt_se, flags);
|
|
}
|
|
enqueue_top_rt_rq(&rq->rt);
|
|
}
|
|
|
|
/*
|
|
* Adding/removing a task to/from a priority array:
|
|
*/
|
|
static void
|
|
enqueue_task_rt(struct rq *rq, struct task_struct *p, int flags)
|
|
{
|
|
struct sched_rt_entity *rt_se = &p->rt;
|
|
|
|
if (flags & ENQUEUE_WAKEUP)
|
|
rt_se->timeout = 0;
|
|
|
|
enqueue_rt_entity(rt_se, flags);
|
|
|
|
if (!task_current(rq, p) && p->nr_cpus_allowed > 1)
|
|
enqueue_pushable_task(rq, p);
|
|
}
|
|
|
|
static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int flags)
|
|
{
|
|
struct sched_rt_entity *rt_se = &p->rt;
|
|
|
|
update_curr_rt(rq);
|
|
dequeue_rt_entity(rt_se, flags);
|
|
|
|
dequeue_pushable_task(rq, p);
|
|
}
|
|
|
|
/*
|
|
* Put task to the head or the end of the run list without the overhead of
|
|
* dequeue followed by enqueue.
|
|
*/
|
|
static void
|
|
requeue_rt_entity(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se, int head)
|
|
{
|
|
if (on_rt_rq(rt_se)) {
|
|
struct rt_prio_array *array = &rt_rq->active;
|
|
struct list_head *queue = array->queue + rt_se_prio(rt_se);
|
|
|
|
if (head)
|
|
list_move(&rt_se->run_list, queue);
|
|
else
|
|
list_move_tail(&rt_se->run_list, queue);
|
|
}
|
|
}
|
|
|
|
static void requeue_task_rt(struct rq *rq, struct task_struct *p, int head)
|
|
{
|
|
struct sched_rt_entity *rt_se = &p->rt;
|
|
struct rt_rq *rt_rq;
|
|
|
|
for_each_sched_rt_entity(rt_se) {
|
|
rt_rq = rt_rq_of_se(rt_se);
|
|
requeue_rt_entity(rt_rq, rt_se, head);
|
|
}
|
|
}
|
|
|
|
static void yield_task_rt(struct rq *rq)
|
|
{
|
|
requeue_task_rt(rq, rq->curr, 0);
|
|
}
|
|
|
|
#ifdef CONFIG_SMP
|
|
static int find_lowest_rq(struct task_struct *task);
|
|
|
|
static int
|
|
select_task_rq_rt(struct task_struct *p, int cpu, int sd_flag, int flags)
|
|
{
|
|
struct task_struct *curr;
|
|
struct rq *rq;
|
|
|
|
/* For anything but wake ups, just return the task_cpu */
|
|
if (sd_flag != SD_BALANCE_WAKE && sd_flag != SD_BALANCE_FORK)
|
|
goto out;
|
|
|
|
rq = cpu_rq(cpu);
|
|
|
|
rcu_read_lock();
|
|
curr = READ_ONCE(rq->curr); /* unlocked access */
|
|
|
|
/*
|
|
* If the current task on @p's runqueue is an RT task, then
|
|
* try to see if we can wake this RT task up on another
|
|
* runqueue. Otherwise simply start this RT task
|
|
* on its current runqueue.
|
|
*
|
|
* We want to avoid overloading runqueues. If the woken
|
|
* task is a higher priority, then it will stay on this CPU
|
|
* and the lower prio task should be moved to another CPU.
|
|
* Even though this will probably make the lower prio task
|
|
* lose its cache, we do not want to bounce a higher task
|
|
* around just because it gave up its CPU, perhaps for a
|
|
* lock?
|
|
*
|
|
* For equal prio tasks, we just let the scheduler sort it out.
|
|
*
|
|
* Otherwise, just let it ride on the affined RQ and the
|
|
* post-schedule router will push the preempted task away
|
|
*
|
|
* This test is optimistic, if we get it wrong the load-balancer
|
|
* will have to sort it out.
|
|
*/
|
|
if (curr && unlikely(rt_task(curr)) &&
|
|
(curr->nr_cpus_allowed < 2 ||
|
|
curr->prio <= p->prio)) {
|
|
int target = find_lowest_rq(p);
|
|
|
|
/*
|
|
* Don't bother moving it if the destination CPU is
|
|
* not running a lower priority task.
|
|
*/
|
|
if (target != -1 &&
|
|
p->prio < cpu_rq(target)->rt.highest_prio.curr)
|
|
cpu = target;
|
|
}
|
|
rcu_read_unlock();
|
|
|
|
out:
|
|
return cpu;
|
|
}
|
|
|
|
static void check_preempt_equal_prio(struct rq *rq, struct task_struct *p)
|
|
{
|
|
/*
|
|
* Current can't be migrated, useless to reschedule,
|
|
* let's hope p can move out.
|
|
*/
|
|
if (rq->curr->nr_cpus_allowed == 1 ||
|
|
!cpupri_find(&rq->rd->cpupri, rq->curr, NULL))
|
|
return;
|
|
|
|
/*
|
|
* p is migratable, so let's not schedule it and
|
|
* see if it is pushed or pulled somewhere else.
|
|
*/
|
|
if (p->nr_cpus_allowed != 1
|
|
&& cpupri_find(&rq->rd->cpupri, p, NULL))
|
|
return;
|
|
|
|
/*
|
|
* There appears to be other cpus that can accept
|
|
* current and none to run 'p', so lets reschedule
|
|
* to try and push current away:
|
|
*/
|
|
requeue_task_rt(rq, p, 1);
|
|
resched_curr(rq);
|
|
}
|
|
|
|
#endif /* CONFIG_SMP */
|
|
|
|
/*
|
|
* Preempt the current task with a newly woken task if needed:
|
|
*/
|
|
static void check_preempt_curr_rt(struct rq *rq, struct task_struct *p, int flags)
|
|
{
|
|
if (p->prio < rq->curr->prio) {
|
|
resched_curr(rq);
|
|
return;
|
|
}
|
|
|
|
#ifdef CONFIG_SMP
|
|
/*
|
|
* If:
|
|
*
|
|
* - the newly woken task is of equal priority to the current task
|
|
* - the newly woken task is non-migratable while current is migratable
|
|
* - current will be preempted on the next reschedule
|
|
*
|
|
* we should check to see if current can readily move to a different
|
|
* cpu. If so, we will reschedule to allow the push logic to try
|
|
* to move current somewhere else, making room for our non-migratable
|
|
* task.
|
|
*/
|
|
if (p->prio == rq->curr->prio && !test_tsk_need_resched(rq->curr))
|
|
check_preempt_equal_prio(rq, p);
|
|
#endif
|
|
}
|
|
|
|
static struct sched_rt_entity *pick_next_rt_entity(struct rq *rq,
|
|
struct rt_rq *rt_rq)
|
|
{
|
|
struct rt_prio_array *array = &rt_rq->active;
|
|
struct sched_rt_entity *next = NULL;
|
|
struct list_head *queue;
|
|
int idx;
|
|
|
|
idx = sched_find_first_bit(array->bitmap);
|
|
BUG_ON(idx >= MAX_RT_PRIO);
|
|
|
|
queue = array->queue + idx;
|
|
next = list_entry(queue->next, struct sched_rt_entity, run_list);
|
|
|
|
return next;
|
|
}
|
|
|
|
static struct task_struct *_pick_next_task_rt(struct rq *rq)
|
|
{
|
|
struct sched_rt_entity *rt_se;
|
|
struct task_struct *p;
|
|
struct rt_rq *rt_rq = &rq->rt;
|
|
|
|
do {
|
|
rt_se = pick_next_rt_entity(rq, rt_rq);
|
|
BUG_ON(!rt_se);
|
|
rt_rq = group_rt_rq(rt_se);
|
|
} while (rt_rq);
|
|
|
|
p = rt_task_of(rt_se);
|
|
p->se.exec_start = rq_clock_task(rq);
|
|
|
|
return p;
|
|
}
|
|
|
|
static struct task_struct *
|
|
pick_next_task_rt(struct rq *rq, struct task_struct *prev)
|
|
{
|
|
struct task_struct *p;
|
|
struct rt_rq *rt_rq = &rq->rt;
|
|
|
|
if (need_pull_rt_task(rq, prev)) {
|
|
/*
|
|
* This is OK, because current is on_cpu, which avoids it being
|
|
* picked for load-balance and preemption/IRQs are still
|
|
* disabled avoiding further scheduler activity on it and we're
|
|
* being very careful to re-start the picking loop.
|
|
*/
|
|
lockdep_unpin_lock(&rq->lock);
|
|
pull_rt_task(rq);
|
|
lockdep_pin_lock(&rq->lock);
|
|
/*
|
|
* pull_rt_task() can drop (and re-acquire) rq->lock; this
|
|
* means a dl or stop task can slip in, in which case we need
|
|
* to re-start task selection.
|
|
*/
|
|
if (unlikely((rq->stop && task_on_rq_queued(rq->stop)) ||
|
|
rq->dl.dl_nr_running))
|
|
return RETRY_TASK;
|
|
}
|
|
|
|
/*
|
|
* We may dequeue prev's rt_rq in put_prev_task().
|
|
* So, we update time before rt_nr_running check.
|
|
*/
|
|
if (prev->sched_class == &rt_sched_class)
|
|
update_curr_rt(rq);
|
|
|
|
if (!rt_rq->rt_queued)
|
|
return NULL;
|
|
|
|
put_prev_task(rq, prev);
|
|
|
|
p = _pick_next_task_rt(rq);
|
|
|
|
/* The running task is never eligible for pushing */
|
|
dequeue_pushable_task(rq, p);
|
|
|
|
queue_push_tasks(rq);
|
|
|
|
return p;
|
|
}
|
|
|
|
static void put_prev_task_rt(struct rq *rq, struct task_struct *p)
|
|
{
|
|
update_curr_rt(rq);
|
|
|
|
/*
|
|
* The previous task needs to be made eligible for pushing
|
|
* if it is still active
|
|
*/
|
|
if (on_rt_rq(&p->rt) && p->nr_cpus_allowed > 1)
|
|
enqueue_pushable_task(rq, p);
|
|
}
|
|
|
|
#ifdef CONFIG_SMP
|
|
|
|
/* Only try algorithms three times */
|
|
#define RT_MAX_TRIES 3
|
|
|
|
static int pick_rt_task(struct rq *rq, struct task_struct *p, int cpu)
|
|
{
|
|
if (!task_running(rq, p) &&
|
|
cpumask_test_cpu(cpu, tsk_cpus_allowed(p)))
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Return the highest pushable rq's task, which is suitable to be executed
|
|
* on the cpu, NULL otherwise
|
|
*/
|
|
static struct task_struct *pick_highest_pushable_task(struct rq *rq, int cpu)
|
|
{
|
|
struct plist_head *head = &rq->rt.pushable_tasks;
|
|
struct task_struct *p;
|
|
|
|
if (!has_pushable_tasks(rq))
|
|
return NULL;
|
|
|
|
plist_for_each_entry(p, head, pushable_tasks) {
|
|
if (pick_rt_task(rq, p, cpu))
|
|
return p;
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static DEFINE_PER_CPU(cpumask_var_t, local_cpu_mask);
|
|
|
|
static int find_lowest_rq(struct task_struct *task)
|
|
{
|
|
struct sched_domain *sd;
|
|
struct cpumask *lowest_mask = this_cpu_cpumask_var_ptr(local_cpu_mask);
|
|
int this_cpu = smp_processor_id();
|
|
int cpu = task_cpu(task);
|
|
|
|
/* Make sure the mask is initialized first */
|
|
if (unlikely(!lowest_mask))
|
|
return -1;
|
|
|
|
if (task->nr_cpus_allowed == 1)
|
|
return -1; /* No other targets possible */
|
|
|
|
if (!cpupri_find(&task_rq(task)->rd->cpupri, task, lowest_mask))
|
|
return -1; /* No targets found */
|
|
|
|
/*
|
|
* At this point we have built a mask of cpus representing the
|
|
* lowest priority tasks in the system. Now we want to elect
|
|
* the best one based on our affinity and topology.
|
|
*
|
|
* We prioritize the last cpu that the task executed on since
|
|
* it is most likely cache-hot in that location.
|
|
*/
|
|
if (cpumask_test_cpu(cpu, lowest_mask))
|
|
return cpu;
|
|
|
|
/*
|
|
* Otherwise, we consult the sched_domains span maps to figure
|
|
* out which cpu is logically closest to our hot cache data.
|
|
*/
|
|
if (!cpumask_test_cpu(this_cpu, lowest_mask))
|
|
this_cpu = -1; /* Skip this_cpu opt if not among lowest */
|
|
|
|
rcu_read_lock();
|
|
for_each_domain(cpu, sd) {
|
|
if (sd->flags & SD_WAKE_AFFINE) {
|
|
int best_cpu;
|
|
|
|
/*
|
|
* "this_cpu" is cheaper to preempt than a
|
|
* remote processor.
|
|
*/
|
|
if (this_cpu != -1 &&
|
|
cpumask_test_cpu(this_cpu, sched_domain_span(sd))) {
|
|
rcu_read_unlock();
|
|
return this_cpu;
|
|
}
|
|
|
|
best_cpu = cpumask_first_and(lowest_mask,
|
|
sched_domain_span(sd));
|
|
if (best_cpu < nr_cpu_ids) {
|
|
rcu_read_unlock();
|
|
return best_cpu;
|
|
}
|
|
}
|
|
}
|
|
rcu_read_unlock();
|
|
|
|
/*
|
|
* And finally, if there were no matches within the domains
|
|
* just give the caller *something* to work with from the compatible
|
|
* locations.
|
|
*/
|
|
if (this_cpu != -1)
|
|
return this_cpu;
|
|
|
|
cpu = cpumask_any(lowest_mask);
|
|
if (cpu < nr_cpu_ids)
|
|
return cpu;
|
|
return -1;
|
|
}
|
|
|
|
/* Will lock the rq it finds */
|
|
static struct rq *find_lock_lowest_rq(struct task_struct *task, struct rq *rq)
|
|
{
|
|
struct rq *lowest_rq = NULL;
|
|
int tries;
|
|
int cpu;
|
|
|
|
for (tries = 0; tries < RT_MAX_TRIES; tries++) {
|
|
cpu = find_lowest_rq(task);
|
|
|
|
if ((cpu == -1) || (cpu == rq->cpu))
|
|
break;
|
|
|
|
lowest_rq = cpu_rq(cpu);
|
|
|
|
if (lowest_rq->rt.highest_prio.curr <= task->prio) {
|
|
/*
|
|
* Target rq has tasks of equal or higher priority,
|
|
* retrying does not release any lock and is unlikely
|
|
* to yield a different result.
|
|
*/
|
|
lowest_rq = NULL;
|
|
break;
|
|
}
|
|
|
|
/* if the prio of this runqueue changed, try again */
|
|
if (double_lock_balance(rq, lowest_rq)) {
|
|
/*
|
|
* We had to unlock the run queue. In
|
|
* the mean time, task could have
|
|
* migrated already or had its affinity changed.
|
|
* Also make sure that it wasn't scheduled on its rq.
|
|
*/
|
|
if (unlikely(task_rq(task) != rq ||
|
|
!cpumask_test_cpu(lowest_rq->cpu,
|
|
tsk_cpus_allowed(task)) ||
|
|
task_running(rq, task) ||
|
|
!task_on_rq_queued(task))) {
|
|
|
|
double_unlock_balance(rq, lowest_rq);
|
|
lowest_rq = NULL;
|
|
break;
|
|
}
|
|
}
|
|
|
|
/* If this rq is still suitable use it. */
|
|
if (lowest_rq->rt.highest_prio.curr > task->prio)
|
|
break;
|
|
|
|
/* try again */
|
|
double_unlock_balance(rq, lowest_rq);
|
|
lowest_rq = NULL;
|
|
}
|
|
|
|
return lowest_rq;
|
|
}
|
|
|
|
static struct task_struct *pick_next_pushable_task(struct rq *rq)
|
|
{
|
|
struct task_struct *p;
|
|
|
|
if (!has_pushable_tasks(rq))
|
|
return NULL;
|
|
|
|
p = plist_first_entry(&rq->rt.pushable_tasks,
|
|
struct task_struct, pushable_tasks);
|
|
|
|
BUG_ON(rq->cpu != task_cpu(p));
|
|
BUG_ON(task_current(rq, p));
|
|
BUG_ON(p->nr_cpus_allowed <= 1);
|
|
|
|
BUG_ON(!task_on_rq_queued(p));
|
|
BUG_ON(!rt_task(p));
|
|
|
|
return p;
|
|
}
|
|
|
|
/*
|
|
* If the current CPU has more than one RT task, see if the non
|
|
* running task can migrate over to a CPU that is running a task
|
|
* of lesser priority.
|
|
*/
|
|
static int push_rt_task(struct rq *rq)
|
|
{
|
|
struct task_struct *next_task;
|
|
struct rq *lowest_rq;
|
|
int ret = 0;
|
|
|
|
if (!rq->rt.overloaded)
|
|
return 0;
|
|
|
|
next_task = pick_next_pushable_task(rq);
|
|
if (!next_task)
|
|
return 0;
|
|
|
|
retry:
|
|
if (unlikely(next_task == rq->curr)) {
|
|
WARN_ON(1);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* It's possible that the next_task slipped in of
|
|
* higher priority than current. If that's the case
|
|
* just reschedule current.
|
|
*/
|
|
if (unlikely(next_task->prio < rq->curr->prio)) {
|
|
resched_curr(rq);
|
|
return 0;
|
|
}
|
|
|
|
/* We might release rq lock */
|
|
get_task_struct(next_task);
|
|
|
|
/* find_lock_lowest_rq locks the rq if found */
|
|
lowest_rq = find_lock_lowest_rq(next_task, rq);
|
|
if (!lowest_rq) {
|
|
struct task_struct *task;
|
|
/*
|
|
* find_lock_lowest_rq releases rq->lock
|
|
* so it is possible that next_task has migrated.
|
|
*
|
|
* We need to make sure that the task is still on the same
|
|
* run-queue and is also still the next task eligible for
|
|
* pushing.
|
|
*/
|
|
task = pick_next_pushable_task(rq);
|
|
if (task_cpu(next_task) == rq->cpu && task == next_task) {
|
|
/*
|
|
* The task hasn't migrated, and is still the next
|
|
* eligible task, but we failed to find a run-queue
|
|
* to push it to. Do not retry in this case, since
|
|
* other cpus will pull from us when ready.
|
|
*/
|
|
goto out;
|
|
}
|
|
|
|
if (!task)
|
|
/* No more tasks, just exit */
|
|
goto out;
|
|
|
|
/*
|
|
* Something has shifted, try again.
|
|
*/
|
|
put_task_struct(next_task);
|
|
next_task = task;
|
|
goto retry;
|
|
}
|
|
|
|
deactivate_task(rq, next_task, 0);
|
|
set_task_cpu(next_task, lowest_rq->cpu);
|
|
activate_task(lowest_rq, next_task, 0);
|
|
ret = 1;
|
|
|
|
resched_curr(lowest_rq);
|
|
|
|
double_unlock_balance(rq, lowest_rq);
|
|
|
|
out:
|
|
put_task_struct(next_task);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void push_rt_tasks(struct rq *rq)
|
|
{
|
|
/* push_rt_task will return true if it moved an RT */
|
|
while (push_rt_task(rq))
|
|
;
|
|
}
|
|
|
|
#ifdef HAVE_RT_PUSH_IPI
|
|
/*
|
|
* The search for the next cpu always starts at rq->cpu and ends
|
|
* when we reach rq->cpu again. It will never return rq->cpu.
|
|
* This returns the next cpu to check, or nr_cpu_ids if the loop
|
|
* is complete.
|
|
*
|
|
* rq->rt.push_cpu holds the last cpu returned by this function,
|
|
* or if this is the first instance, it must hold rq->cpu.
|
|
*/
|
|
static int rto_next_cpu(struct rq *rq)
|
|
{
|
|
int prev_cpu = rq->rt.push_cpu;
|
|
int cpu;
|
|
|
|
cpu = cpumask_next(prev_cpu, rq->rd->rto_mask);
|
|
|
|
/*
|
|
* If the previous cpu is less than the rq's CPU, then it already
|
|
* passed the end of the mask, and has started from the beginning.
|
|
* We end if the next CPU is greater or equal to rq's CPU.
|
|
*/
|
|
if (prev_cpu < rq->cpu) {
|
|
if (cpu >= rq->cpu)
|
|
return nr_cpu_ids;
|
|
|
|
} else if (cpu >= nr_cpu_ids) {
|
|
/*
|
|
* We passed the end of the mask, start at the beginning.
|
|
* If the result is greater or equal to the rq's CPU, then
|
|
* the loop is finished.
|
|
*/
|
|
cpu = cpumask_first(rq->rd->rto_mask);
|
|
if (cpu >= rq->cpu)
|
|
return nr_cpu_ids;
|
|
}
|
|
rq->rt.push_cpu = cpu;
|
|
|
|
/* Return cpu to let the caller know if the loop is finished or not */
|
|
return cpu;
|
|
}
|
|
|
|
static int find_next_push_cpu(struct rq *rq)
|
|
{
|
|
struct rq *next_rq;
|
|
int cpu;
|
|
|
|
while (1) {
|
|
cpu = rto_next_cpu(rq);
|
|
if (cpu >= nr_cpu_ids)
|
|
break;
|
|
next_rq = cpu_rq(cpu);
|
|
|
|
/* Make sure the next rq can push to this rq */
|
|
if (next_rq->rt.highest_prio.next < rq->rt.highest_prio.curr)
|
|
break;
|
|
}
|
|
|
|
return cpu;
|
|
}
|
|
|
|
#define RT_PUSH_IPI_EXECUTING 1
|
|
#define RT_PUSH_IPI_RESTART 2
|
|
|
|
static void tell_cpu_to_push(struct rq *rq)
|
|
{
|
|
int cpu;
|
|
|
|
if (rq->rt.push_flags & RT_PUSH_IPI_EXECUTING) {
|
|
raw_spin_lock(&rq->rt.push_lock);
|
|
/* Make sure it's still executing */
|
|
if (rq->rt.push_flags & RT_PUSH_IPI_EXECUTING) {
|
|
/*
|
|
* Tell the IPI to restart the loop as things have
|
|
* changed since it started.
|
|
*/
|
|
rq->rt.push_flags |= RT_PUSH_IPI_RESTART;
|
|
raw_spin_unlock(&rq->rt.push_lock);
|
|
return;
|
|
}
|
|
raw_spin_unlock(&rq->rt.push_lock);
|
|
}
|
|
|
|
/* When here, there's no IPI going around */
|
|
|
|
rq->rt.push_cpu = rq->cpu;
|
|
cpu = find_next_push_cpu(rq);
|
|
if (cpu >= nr_cpu_ids)
|
|
return;
|
|
|
|
rq->rt.push_flags = RT_PUSH_IPI_EXECUTING;
|
|
|
|
irq_work_queue_on(&rq->rt.push_work, cpu);
|
|
}
|
|
|
|
/* Called from hardirq context */
|
|
static void try_to_push_tasks(void *arg)
|
|
{
|
|
struct rt_rq *rt_rq = arg;
|
|
struct rq *rq, *src_rq;
|
|
int this_cpu;
|
|
int cpu;
|
|
|
|
this_cpu = rt_rq->push_cpu;
|
|
|
|
/* Paranoid check */
|
|
BUG_ON(this_cpu != smp_processor_id());
|
|
|
|
rq = cpu_rq(this_cpu);
|
|
src_rq = rq_of_rt_rq(rt_rq);
|
|
|
|
again:
|
|
if (has_pushable_tasks(rq)) {
|
|
raw_spin_lock(&rq->lock);
|
|
push_rt_task(rq);
|
|
raw_spin_unlock(&rq->lock);
|
|
}
|
|
|
|
/* Pass the IPI to the next rt overloaded queue */
|
|
raw_spin_lock(&rt_rq->push_lock);
|
|
/*
|
|
* If the source queue changed since the IPI went out,
|
|
* we need to restart the search from that CPU again.
|
|
*/
|
|
if (rt_rq->push_flags & RT_PUSH_IPI_RESTART) {
|
|
rt_rq->push_flags &= ~RT_PUSH_IPI_RESTART;
|
|
rt_rq->push_cpu = src_rq->cpu;
|
|
}
|
|
|
|
cpu = find_next_push_cpu(src_rq);
|
|
|
|
if (cpu >= nr_cpu_ids)
|
|
rt_rq->push_flags &= ~RT_PUSH_IPI_EXECUTING;
|
|
raw_spin_unlock(&rt_rq->push_lock);
|
|
|
|
if (cpu >= nr_cpu_ids)
|
|
return;
|
|
|
|
/*
|
|
* It is possible that a restart caused this CPU to be
|
|
* chosen again. Don't bother with an IPI, just see if we
|
|
* have more to push.
|
|
*/
|
|
if (unlikely(cpu == rq->cpu))
|
|
goto again;
|
|
|
|
/* Try the next RT overloaded CPU */
|
|
irq_work_queue_on(&rt_rq->push_work, cpu);
|
|
}
|
|
|
|
static void push_irq_work_func(struct irq_work *work)
|
|
{
|
|
struct rt_rq *rt_rq = container_of(work, struct rt_rq, push_work);
|
|
|
|
try_to_push_tasks(rt_rq);
|
|
}
|
|
#endif /* HAVE_RT_PUSH_IPI */
|
|
|
|
static void pull_rt_task(struct rq *this_rq)
|
|
{
|
|
int this_cpu = this_rq->cpu, cpu;
|
|
bool resched = false;
|
|
struct task_struct *p;
|
|
struct rq *src_rq;
|
|
|
|
if (likely(!rt_overloaded(this_rq)))
|
|
return;
|
|
|
|
/*
|
|
* Match the barrier from rt_set_overloaded; this guarantees that if we
|
|
* see overloaded we must also see the rto_mask bit.
|
|
*/
|
|
smp_rmb();
|
|
|
|
#ifdef HAVE_RT_PUSH_IPI
|
|
if (sched_feat(RT_PUSH_IPI)) {
|
|
tell_cpu_to_push(this_rq);
|
|
return;
|
|
}
|
|
#endif
|
|
|
|
for_each_cpu(cpu, this_rq->rd->rto_mask) {
|
|
if (this_cpu == cpu)
|
|
continue;
|
|
|
|
src_rq = cpu_rq(cpu);
|
|
|
|
/*
|
|
* Don't bother taking the src_rq->lock if the next highest
|
|
* task is known to be lower-priority than our current task.
|
|
* This may look racy, but if this value is about to go
|
|
* logically higher, the src_rq will push this task away.
|
|
* And if its going logically lower, we do not care
|
|
*/
|
|
if (src_rq->rt.highest_prio.next >=
|
|
this_rq->rt.highest_prio.curr)
|
|
continue;
|
|
|
|
/*
|
|
* We can potentially drop this_rq's lock in
|
|
* double_lock_balance, and another CPU could
|
|
* alter this_rq
|
|
*/
|
|
double_lock_balance(this_rq, src_rq);
|
|
|
|
/*
|
|
* We can pull only a task, which is pushable
|
|
* on its rq, and no others.
|
|
*/
|
|
p = pick_highest_pushable_task(src_rq, this_cpu);
|
|
|
|
/*
|
|
* Do we have an RT task that preempts
|
|
* the to-be-scheduled task?
|
|
*/
|
|
if (p && (p->prio < this_rq->rt.highest_prio.curr)) {
|
|
WARN_ON(p == src_rq->curr);
|
|
WARN_ON(!task_on_rq_queued(p));
|
|
|
|
/*
|
|
* There's a chance that p is higher in priority
|
|
* than what's currently running on its cpu.
|
|
* This is just that p is wakeing up and hasn't
|
|
* had a chance to schedule. We only pull
|
|
* p if it is lower in priority than the
|
|
* current task on the run queue
|
|
*/
|
|
if (p->prio < src_rq->curr->prio)
|
|
goto skip;
|
|
|
|
resched = true;
|
|
|
|
deactivate_task(src_rq, p, 0);
|
|
set_task_cpu(p, this_cpu);
|
|
activate_task(this_rq, p, 0);
|
|
/*
|
|
* We continue with the search, just in
|
|
* case there's an even higher prio task
|
|
* in another runqueue. (low likelihood
|
|
* but possible)
|
|
*/
|
|
}
|
|
skip:
|
|
double_unlock_balance(this_rq, src_rq);
|
|
}
|
|
|
|
if (resched)
|
|
resched_curr(this_rq);
|
|
}
|
|
|
|
/*
|
|
* If we are not running and we are not going to reschedule soon, we should
|
|
* try to push tasks away now
|
|
*/
|
|
static void task_woken_rt(struct rq *rq, struct task_struct *p)
|
|
{
|
|
if (!task_running(rq, p) &&
|
|
!test_tsk_need_resched(rq->curr) &&
|
|
p->nr_cpus_allowed > 1 &&
|
|
(dl_task(rq->curr) || rt_task(rq->curr)) &&
|
|
(rq->curr->nr_cpus_allowed < 2 ||
|
|
rq->curr->prio <= p->prio))
|
|
push_rt_tasks(rq);
|
|
}
|
|
|
|
/* Assumes rq->lock is held */
|
|
static void rq_online_rt(struct rq *rq)
|
|
{
|
|
if (rq->rt.overloaded)
|
|
rt_set_overload(rq);
|
|
|
|
__enable_runtime(rq);
|
|
|
|
cpupri_set(&rq->rd->cpupri, rq->cpu, rq->rt.highest_prio.curr);
|
|
}
|
|
|
|
/* Assumes rq->lock is held */
|
|
static void rq_offline_rt(struct rq *rq)
|
|
{
|
|
if (rq->rt.overloaded)
|
|
rt_clear_overload(rq);
|
|
|
|
__disable_runtime(rq);
|
|
|
|
cpupri_set(&rq->rd->cpupri, rq->cpu, CPUPRI_INVALID);
|
|
}
|
|
|
|
/*
|
|
* When switch from the rt queue, we bring ourselves to a position
|
|
* that we might want to pull RT tasks from other runqueues.
|
|
*/
|
|
static void switched_from_rt(struct rq *rq, struct task_struct *p)
|
|
{
|
|
/*
|
|
* If there are other RT tasks then we will reschedule
|
|
* and the scheduling of the other RT tasks will handle
|
|
* the balancing. But if we are the last RT task
|
|
* we may need to handle the pulling of RT tasks
|
|
* now.
|
|
*/
|
|
if (!task_on_rq_queued(p) || rq->rt.rt_nr_running)
|
|
return;
|
|
|
|
queue_pull_task(rq);
|
|
}
|
|
|
|
void __init init_sched_rt_class(void)
|
|
{
|
|
unsigned int i;
|
|
|
|
for_each_possible_cpu(i) {
|
|
zalloc_cpumask_var_node(&per_cpu(local_cpu_mask, i),
|
|
GFP_KERNEL, cpu_to_node(i));
|
|
}
|
|
}
|
|
#endif /* CONFIG_SMP */
|
|
|
|
/*
|
|
* When switching a task to RT, we may overload the runqueue
|
|
* with RT tasks. In this case we try to push them off to
|
|
* other runqueues.
|
|
*/
|
|
static void switched_to_rt(struct rq *rq, struct task_struct *p)
|
|
{
|
|
/*
|
|
* If we are already running, then there's nothing
|
|
* that needs to be done. But if we are not running
|
|
* we may need to preempt the current running task.
|
|
* If that current running task is also an RT task
|
|
* then see if we can move to another run queue.
|
|
*/
|
|
if (task_on_rq_queued(p) && rq->curr != p) {
|
|
#ifdef CONFIG_SMP
|
|
if (p->nr_cpus_allowed > 1 && rq->rt.overloaded)
|
|
queue_push_tasks(rq);
|
|
#else
|
|
if (p->prio < rq->curr->prio)
|
|
resched_curr(rq);
|
|
#endif /* CONFIG_SMP */
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Priority of the task has changed. This may cause
|
|
* us to initiate a push or pull.
|
|
*/
|
|
static void
|
|
prio_changed_rt(struct rq *rq, struct task_struct *p, int oldprio)
|
|
{
|
|
if (!task_on_rq_queued(p))
|
|
return;
|
|
|
|
if (rq->curr == p) {
|
|
#ifdef CONFIG_SMP
|
|
/*
|
|
* If our priority decreases while running, we
|
|
* may need to pull tasks to this runqueue.
|
|
*/
|
|
if (oldprio < p->prio)
|
|
queue_pull_task(rq);
|
|
|
|
/*
|
|
* If there's a higher priority task waiting to run
|
|
* then reschedule.
|
|
*/
|
|
if (p->prio > rq->rt.highest_prio.curr)
|
|
resched_curr(rq);
|
|
#else
|
|
/* For UP simply resched on drop of prio */
|
|
if (oldprio < p->prio)
|
|
resched_curr(rq);
|
|
#endif /* CONFIG_SMP */
|
|
} else {
|
|
/*
|
|
* This task is not running, but if it is
|
|
* greater than the current running task
|
|
* then reschedule.
|
|
*/
|
|
if (p->prio < rq->curr->prio)
|
|
resched_curr(rq);
|
|
}
|
|
}
|
|
|
|
static void watchdog(struct rq *rq, struct task_struct *p)
|
|
{
|
|
unsigned long soft, hard;
|
|
|
|
/* max may change after cur was read, this will be fixed next tick */
|
|
soft = task_rlimit(p, RLIMIT_RTTIME);
|
|
hard = task_rlimit_max(p, RLIMIT_RTTIME);
|
|
|
|
if (soft != RLIM_INFINITY) {
|
|
unsigned long next;
|
|
|
|
if (p->rt.watchdog_stamp != jiffies) {
|
|
p->rt.timeout++;
|
|
p->rt.watchdog_stamp = jiffies;
|
|
}
|
|
|
|
next = DIV_ROUND_UP(min(soft, hard), USEC_PER_SEC/HZ);
|
|
if (p->rt.timeout > next)
|
|
p->cputime_expires.sched_exp = p->se.sum_exec_runtime;
|
|
}
|
|
}
|
|
|
|
static void task_tick_rt(struct rq *rq, struct task_struct *p, int queued)
|
|
{
|
|
struct sched_rt_entity *rt_se = &p->rt;
|
|
|
|
update_curr_rt(rq);
|
|
|
|
watchdog(rq, p);
|
|
|
|
/*
|
|
* RR tasks need a special form of timeslice management.
|
|
* FIFO tasks have no timeslices.
|
|
*/
|
|
if (p->policy != SCHED_RR)
|
|
return;
|
|
|
|
if (--p->rt.time_slice)
|
|
return;
|
|
|
|
p->rt.time_slice = sched_rr_timeslice;
|
|
|
|
/*
|
|
* Requeue to the end of queue if we (and all of our ancestors) are not
|
|
* the only element on the queue
|
|
*/
|
|
for_each_sched_rt_entity(rt_se) {
|
|
if (rt_se->run_list.prev != rt_se->run_list.next) {
|
|
requeue_task_rt(rq, p, 0);
|
|
resched_curr(rq);
|
|
return;
|
|
}
|
|
}
|
|
}
|
|
|
|
static void set_curr_task_rt(struct rq *rq)
|
|
{
|
|
struct task_struct *p = rq->curr;
|
|
|
|
p->se.exec_start = rq_clock_task(rq);
|
|
|
|
/* The running task is never eligible for pushing */
|
|
dequeue_pushable_task(rq, p);
|
|
}
|
|
|
|
static unsigned int get_rr_interval_rt(struct rq *rq, struct task_struct *task)
|
|
{
|
|
/*
|
|
* Time slice is 0 for SCHED_FIFO tasks
|
|
*/
|
|
if (task->policy == SCHED_RR)
|
|
return sched_rr_timeslice;
|
|
else
|
|
return 0;
|
|
}
|
|
|
|
const struct sched_class rt_sched_class = {
|
|
.next = &fair_sched_class,
|
|
.enqueue_task = enqueue_task_rt,
|
|
.dequeue_task = dequeue_task_rt,
|
|
.yield_task = yield_task_rt,
|
|
|
|
.check_preempt_curr = check_preempt_curr_rt,
|
|
|
|
.pick_next_task = pick_next_task_rt,
|
|
.put_prev_task = put_prev_task_rt,
|
|
|
|
#ifdef CONFIG_SMP
|
|
.select_task_rq = select_task_rq_rt,
|
|
|
|
.set_cpus_allowed = set_cpus_allowed_common,
|
|
.rq_online = rq_online_rt,
|
|
.rq_offline = rq_offline_rt,
|
|
.task_woken = task_woken_rt,
|
|
.switched_from = switched_from_rt,
|
|
#endif
|
|
|
|
.set_curr_task = set_curr_task_rt,
|
|
.task_tick = task_tick_rt,
|
|
|
|
.get_rr_interval = get_rr_interval_rt,
|
|
|
|
.prio_changed = prio_changed_rt,
|
|
.switched_to = switched_to_rt,
|
|
|
|
.update_curr = update_curr_rt,
|
|
};
|
|
|
|
#ifdef CONFIG_SCHED_DEBUG
|
|
extern void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq);
|
|
|
|
void print_rt_stats(struct seq_file *m, int cpu)
|
|
{
|
|
rt_rq_iter_t iter;
|
|
struct rt_rq *rt_rq;
|
|
|
|
rcu_read_lock();
|
|
for_each_rt_rq(rt_rq, iter, cpu_rq(cpu))
|
|
print_rt_rq(m, cpu, rt_rq);
|
|
rcu_read_unlock();
|
|
}
|
|
#endif /* CONFIG_SCHED_DEBUG */
|