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* posix-cpu-timers: Fix two trivial commentsYi Wang2019-10-231-3/+3
| | | | | | | | | | | | | | | | Recent changes modified the function arguments of thread_group_sample_cputime() and task_cputimers_expired(), but forgot to update the comments. Fix it up. [ tglx: Changed the argument name of task_cputimers_expired() as the pointer points to an array of samples. ] Fixes: b7be4ef1365d ("posix-cpu-timers: Switch thread group sampling to array") Fixes: 001f7971433a ("posix-cpu-timers: Make expiry checks array based") Signed-off-by: Yi Wang <wang.yi59@zte.com.cn> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/1571643852-21848-1-git-send-email-wang.yi59@zte.com.cn
* timers/sched_clock: Include local timekeeping.h for missing declarationsBen Dooks (Codethink)2019-10-231-0/+2
| | | | | | | | | | | | | | Include the timekeeping.h header to get the declaration of the sched_clock_{suspend,resume} functions. Fixes the following sparse warnings: kernel/time/sched_clock.c:275:5: warning: symbol 'sched_clock_suspend' was not declared. Should it be static? kernel/time/sched_clock.c:286:6: warning: symbol 'sched_clock_resume' was not declared. Should it be static? Signed-off-by: Ben Dooks (Codethink) <ben.dooks@codethink.co.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20191022131226.11465-1-ben.dooks@codethink.co.uk
* hrtimer: Annotate lockless access to timer->baseEric Dumazet2019-10-141-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | Followup to commit dd2261ed45aa ("hrtimer: Protect lockless access to timer->base") lock_hrtimer_base() fetches timer->base without lock exclusion. Compiler is allowed to read timer->base twice (even if considered dumb) which could end up trying to lock migration_base and return &migration_base. base = timer->base; if (likely(base != &migration_base)) { /* compiler reads timer->base again, and now (base == &migration_base) raw_spin_lock_irqsave(&base->cpu_base->lock, *flags); if (likely(base == timer->base)) return base; /* == &migration_base ! */ Similarly the write sides must use WRITE_ONCE() to avoid store tearing. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20191008173204.180879-1-edumazet@google.com
* tick: broadcast-hrtimer: Fix a race in bc_set_nextBalasubramani Vivekanandan2019-09-271-33/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When a cpu requests broadcasting, before starting the tick broadcast hrtimer, bc_set_next() checks if the timer callback (bc_handler) is active using hrtimer_try_to_cancel(). But hrtimer_try_to_cancel() does not provide the required synchronization when the callback is active on other core. The callback could have already executed tick_handle_oneshot_broadcast() and could have also returned. But still there is a small time window where the hrtimer_try_to_cancel() returns -1. In that case bc_set_next() returns without doing anything, but the next_event of the tick broadcast clock device is already set to a timeout value. In the race condition diagram below, CPU #1 is running the timer callback and CPU #2 is entering idle state and so calls bc_set_next(). In the worst case, the next_event will contain an expiry time, but the hrtimer will not be started which happens when the racing callback returns HRTIMER_NORESTART. The hrtimer might never recover if all further requests from the CPUs to subscribe to tick broadcast have timeout greater than the next_event of tick broadcast clock device. This leads to cascading of failures and finally noticed as rcu stall warnings Here is a depiction of the race condition CPU #1 (Running timer callback) CPU #2 (Enter idle and subscribe to tick broadcast) --------------------- --------------------- __run_hrtimer() tick_broadcast_enter() bc_handler() __tick_broadcast_oneshot_control() tick_handle_oneshot_broadcast() raw_spin_lock(&tick_broadcast_lock); dev->next_event = KTIME_MAX; //wait for tick_broadcast_lock //next_event for tick broadcast clock set to KTIME_MAX since no other cores subscribed to tick broadcasting raw_spin_unlock(&tick_broadcast_lock); if (dev->next_event == KTIME_MAX) return HRTIMER_NORESTART // callback function exits without restarting the hrtimer //tick_broadcast_lock acquired raw_spin_lock(&tick_broadcast_lock); tick_broadcast_set_event() clockevents_program_event() dev->next_event = expires; bc_set_next() hrtimer_try_to_cancel() //returns -1 since the timer callback is active. Exits without restarting the timer cpu_base->running = NULL; The comment that hrtimer cannot be armed from within the callback is wrong. It is fine to start the hrtimer from within the callback. Also it is safe to start the hrtimer from the enter/exit idle code while the broadcast handler is active. The enter/exit idle code and the broadcast handler are synchronized using tick_broadcast_lock. So there is no need for the existing try to cancel logic. All this can be removed which will eliminate the race condition as well. Fixes: 5d1638acb9f6 ("tick: Introduce hrtimer based broadcast") Originally-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Balasubramani Vivekanandan <balasubramani_vivekanandan@mentor.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20190926135101.12102-2-balasubramani_vivekanandan@mentor.com
* Merge branch 'timers-urgent-for-linus' of ↵Linus Torvalds2019-09-261-3/+5
|\ | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer fix from Ingo Molnar: "Fix a timer expiry bug that would cause spurious delay of timers" * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: timer: Read jiffies once when forwarding base clk
| * timer: Read jiffies once when forwarding base clkLi RongQing2019-09-191-3/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The timer delayed for more than 3 seconds warning was triggered during testing. Workqueue: events_unbound sched_tick_remote RIP: 0010:sched_tick_remote+0xee/0x100 ... Call Trace: process_one_work+0x18c/0x3a0 worker_thread+0x30/0x380 kthread+0x113/0x130 ret_from_fork+0x22/0x40 The reason is that the code in collect_expired_timers() uses jiffies unprotected: if (next_event > jiffies) base->clk = jiffies; As the compiler is allowed to reload the value base->clk can advance between the check and the store and in the worst case advance farther than next event. That causes the timer expiry to be delayed until the wheel pointer wraps around. Convert the code to use READ_ONCE() Fixes: 236968383cf5 ("timers: Optimize collect_expired_timers() for NOHZ") Signed-off-by: Li RongQing <lirongqing@baidu.com> Signed-off-by: Liang ZhiCheng <liangzhicheng@baidu.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/1568894687-14499-1-git-send-email-lirongqing@baidu.com
* | Merge tag 'pm-5.4-rc1' of ↵Linus Torvalds2019-09-171-1/+1
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management updates from Rafael Wysocki: "These include a rework of the main suspend-to-idle code flow (related to the handling of spurious wakeups), a switch over of several users of cpufreq notifiers to QoS-based limits, a new devfreq driver for Tegra20, a new cpuidle driver and governor for virtualized guests, an extension of the wakeup sources framework to expose wakeup sources as device objects in sysfs, and more. Specifics: - Rework the main suspend-to-idle control flow to avoid repeating "noirq" device resume and suspend operations in case of spurious wakeups from the ACPI EC and decouple the ACPI EC wakeups support from the LPS0 _DSM support (Rafael Wysocki). - Extend the wakeup sources framework to expose wakeup sources as device objects in sysfs (Tri Vo, Stephen Boyd). - Expose system suspend statistics in sysfs (Kalesh Singh). - Introduce a new haltpoll cpuidle driver and a new matching governor for virtualized guests wanting to do guest-side polling in the idle loop (Marcelo Tosatti, Joao Martins, Wanpeng Li, Stephen Rothwell). - Fix the menu and teo cpuidle governors to allow the scheduler tick to be stopped if PM QoS is used to limit the CPU idle state exit latency in some cases (Rafael Wysocki). - Increase the resolution of the play_idle() argument to microseconds for more fine-grained injection of CPU idle cycles (Daniel Lezcano). - Switch over some users of cpuidle notifiers to the new QoS-based frequency limits and drop the CPUFREQ_ADJUST and CPUFREQ_NOTIFY policy notifier events (Viresh Kumar). - Add new cpufreq driver based on nvmem for sun50i (Yangtao Li). - Add support for MT8183 and MT8516 to the mediatek cpufreq driver (Andrew-sh.Cheng, Fabien Parent). - Add i.MX8MN support to the imx-cpufreq-dt cpufreq driver (Anson Huang). - Add qcs404 to cpufreq-dt-platdev blacklist (Jorge Ramirez-Ortiz). - Update the qcom cpufreq driver (among other things, to make it easier to extend and to use kryo cpufreq for other nvmem-based SoCs) and add qcs404 support to it (Niklas Cassel, Douglas RAILLARD, Sibi Sankar, Sricharan R). - Fix assorted issues and make assorted minor improvements in the cpufreq code (Colin Ian King, Douglas RAILLARD, Florian Fainelli, Gustavo Silva, Hariprasad Kelam). - Add new devfreq driver for NVidia Tegra20 (Dmitry Osipenko, Arnd Bergmann). - Add new Exynos PPMU events to devfreq events and extend that mechanism (Lukasz Luba). - Fix and clean up the exynos-bus devfreq driver (Kamil Konieczny). - Improve devfreq documentation and governor code, fix spelling typos in devfreq (Ezequiel Garcia, Krzysztof Kozlowski, Leonard Crestez, MyungJoo Ham, Gaël PORTAY). - Add regulators enable and disable to the OPP (operating performance points) framework (Kamil Konieczny). - Update the OPP framework to support multiple opp-suspend properties (Anson Huang). - Fix assorted issues and make assorted minor improvements in the OPP code (Niklas Cassel, Viresh Kumar, Yue Hu). - Clean up the generic power domains (genpd) framework (Ulf Hansson). - Clean up assorted pieces of power management code and documentation (Akinobu Mita, Amit Kucheria, Chuhong Yuan). - Update the pm-graph tool to version 5.5 including multiple fixes and improvements (Todd Brandt). - Update the cpupower utility (Benjamin Weis, Geert Uytterhoeven, Sébastien Szymanski)" * tag 'pm-5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (126 commits) cpuidle-haltpoll: Enable kvm guest polling when dedicated physical CPUs are available cpuidle-haltpoll: do not set an owner to allow modunload cpuidle-haltpoll: return -ENODEV on modinit failure cpuidle-haltpoll: set haltpoll as preferred governor cpuidle: allow governor switch on cpuidle_register_driver() PM: runtime: Documentation: add runtime_status ABI document pm-graph: make setVal unbuffered again for python2 and python3 powercap: idle_inject: Use higher resolution for idle injection cpuidle: play_idle: Increase the resolution to usec cpuidle-haltpoll: vcpu hotplug support cpufreq: Add qcs404 to cpufreq-dt-platdev blacklist cpufreq: qcom: Add support for qcs404 on nvmem driver cpufreq: qcom: Refactor the driver to make it easier to extend cpufreq: qcom: Re-organise kryo cpufreq to use it for other nvmem based qcom socs dt-bindings: opp: Add qcom-opp bindings with properties needed for CPR dt-bindings: opp: qcom-nvmem: Support pstates provided by a power domain Documentation: cpufreq: Update policy notifier documentation cpufreq: Remove CPUFREQ_ADJUST and CPUFREQ_NOTIFY policy notifier events PM / Domains: Verify PM domain type in dev_pm_genpd_set_performance_state() PM / Domains: Simplify genpd_lookup_dev() ...
| * Merge branch 'pm-sleep'Rafael J. Wysocki2019-09-171-1/+1
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * pm-sleep: (29 commits) ACPI: PM: s2idle: Always set up EC GPE for system wakeup ACPI: PM: s2idle: Avoid rearming SCI for wakeup unnecessarily PM / wakeup: Unexport wakeup_source_sysfs_{add,remove}() PM / wakeup: Register wakeup class kobj after device is added PM / wakeup: Fix sysfs registration error path PM / wakeup: Show wakeup sources stats in sysfs PM / wakeup: Use wakeup_source_register() in wakelock.c PM / wakeup: Drop wakeup_source_init(), wakeup_source_prepare() PM: sleep: Replace strncmp() with str_has_prefix() PM: suspend: Fix platform_suspend_prepare_noirq() intel-hid: Disable button array during suspend-to-idle intel-hid: intel-vbtn: Avoid leaking wakeup_mode set ACPI: PM: s2idle: Execute LPS0 _DSM functions with suspended devices ACPI: EC: PM: Make acpi_ec_dispatch_gpe() print debug message ACPI: EC: PM: Consolidate some code depending on PM_SLEEP ACPI: PM: s2idle: Eliminate acpi_sleep_no_ec_events() ACPI: PM: s2idle: Switch EC over to polling during "noirq" suspend ACPI: PM: s2idle: Add acpi.sleep_no_lps0 module parameter ACPI: PM: s2idle: Rearrange lps0_device_attach() PM/sleep: Expose suspend stats in sysfs ...
| | * PM / wakeup: Show wakeup sources stats in sysfsTri Vo2019-08-211-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add an ID and a device pointer to 'struct wakeup_source'. Use them to to expose wakeup sources statistics in sysfs under /sys/class/wakeup/wakeup<ID>/*. Co-developed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Co-developed-by: Stephen Boyd <swboyd@chromium.org> Signed-off-by: Stephen Boyd <swboyd@chromium.org> Signed-off-by: Tri Vo <trong@android.com> Tested-by: Kalesh Singh <kaleshsingh@google.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* | | Merge branch 'timers-core-for-linus' of ↵Linus Torvalds2019-09-179-581/+889
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull core timer updates from Thomas Gleixner: "Timers and timekeeping updates: - A large overhaul of the posix CPU timer code which is a preparation for moving the CPU timer expiry out into task work so it can be properly accounted on the task/process. An update to the bogus permission checks will come later during the merge window as feedback was not complete before heading of for travel. - Switch the timerqueue code to use cached rbtrees and get rid of the homebrewn caching of the leftmost node. - Consolidate hrtimer_init() + hrtimer_init_sleeper() calls into a single function - Implement the separation of hrtimers to be forced to expire in hard interrupt context even when PREEMPT_RT is enabled and mark the affected timers accordingly. - Implement a mechanism for hrtimers and the timer wheel to protect RT against priority inversion and live lock issues when a (hr)timer which should be canceled is currently executing the callback. Instead of infinitely spinning, the task which tries to cancel the timer blocks on a per cpu base expiry lock which is held and released by the (hr)timer expiry code. - Enable the Hyper-V TSC page based sched_clock for Hyper-V guests resulting in faster access to timekeeping functions. - Updates to various clocksource/clockevent drivers and their device tree bindings. - The usual small improvements all over the place" * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (101 commits) posix-cpu-timers: Fix permission check regression posix-cpu-timers: Always clear head pointer on dequeue hrtimer: Add a missing bracket and hide `migration_base' on !SMP posix-cpu-timers: Make expiry_active check actually work correctly posix-timers: Unbreak CONFIG_POSIX_TIMERS=n build tick: Mark sched_timer to expire in hard interrupt context hrtimer: Add kernel doc annotation for HRTIMER_MODE_HARD x86/hyperv: Hide pv_ops access for CONFIG_PARAVIRT=n posix-cpu-timers: Utilize timerqueue for storage posix-cpu-timers: Move state tracking to struct posix_cputimers posix-cpu-timers: Deduplicate rlimit handling posix-cpu-timers: Remove pointless comparisons posix-cpu-timers: Get rid of 64bit divisions posix-cpu-timers: Consolidate timer expiry further posix-cpu-timers: Get rid of zero checks rlimit: Rewrite non-sensical RLIMIT_CPU comment posix-cpu-timers: Respect INFINITY for hard RTTIME limit posix-cpu-timers: Switch thread group sampling to array posix-cpu-timers: Restructure expiry array posix-cpu-timers: Remove cputime_expires ...
| * | | posix-cpu-timers: Fix permission check regressionThomas Gleixner2019-09-101-9/+35
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The recent consolidation of the three permission checks introduced a subtle regression. For timer_create() with a process wide timer it returns the current task if the lookup through the PID which is encoded into the clockid results in returning current. That's broken because it does not validate whether the current task is the group leader. That was caused by the two different variants of permission checks: - posix_cpu_timer_get() allowed access to the process wide clock when the looked up task is current. That's not an issue because the process wide clock is in the shared sighand. - posix_cpu_timer_create() made sure that the looked up task is the group leader. Restore the previous state. Note, that these permission checks are more than questionable, but that's subject to follow up changes. Fixes: 6ae40e3fdcd3 ("posix-cpu-timers: Provide task validation functions") Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1909052314110.1902@nanos.tec.linutronix.de
| * | | hrtimer: Add a missing bracket and hide `migration_base' on !SMPSebastian Andrzej Siewior2019-09-051-1/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The recent change to avoid taking the expiry lock when a timer is currently migrated missed to add a bracket at the end of the if statement leading to compile errors. Since that commit the variable `migration_base' is always used but it is only available on SMP configuration thus leading to another compile error. The changelog says "The timer base and base->cpu_base cannot be NULL in the code path", so it is safe to limit this check to SMP configurations only. Add the missing bracket to the if statement and hide `migration_base' behind CONFIG_SMP bars. [ tglx: Mark the functions inline ... ] Fixes: 68b2c8c1e4210 ("hrtimer: Don't take expiry_lock when timer is currently migrated") Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190904145527.eah7z56ntwobqm6j@linutronix.de
| * | | posix-cpu-timers: Make expiry_active check actually work correctlyThomas Gleixner2019-08-291-4/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The state tracking changes broke the expiry active check by not writing to it and instead sitting timers_active, which is already set. That's not a big issue as the actual expiry is protected by sighand lock, so concurrent handling is not possible. That means that the second task which invokes that function executes the expiry code for nothing. Write to the proper flag. Also add a check whether the flag is set into check_process_timers(). That check had been missing in the code before the rework already. The check for another task handling the expiry of process wide timers was only done in the fastpath check. If the fastpath check returns true because a per task timer expired, then the checking of process wide timers was done in parallel which is as explained above just a waste of cycles. Fixes: 244d49e30653 ("posix-cpu-timers: Move state tracking to struct posix_cputimers") Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Frederic Weisbecker <frederic@kernel.org>
| * | | tick: Mark sched_timer to expire in hard interrupt contextSebastian Andrzej Siewior2019-08-281-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | sched_timer must be initialized with the _HARD mode suffix to ensure expiry in hard interrupt context on RT. The previous conversion to HARD expiry mode missed on one instance in tick_nohz_switch_to_nohz(). Fix it up. Fixes: 902a9f9c50905 ("tick: Mark tick related hrtimers to expiry in hard interrupt context") Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190823113845.12125-3-bigeasy@linutronix.de
| * | | posix-cpu-timers: Utilize timerqueue for storageThomas Gleixner2019-08-281-93/+96
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Using a linear O(N) search for timer insertion affects execution time and D-cache footprint badly with a larger number of timers. Switch the storage to a timerqueue which is already used for hrtimers and alarmtimers. It does not affect the size of struct k_itimer as it.alarm is still larger. The extra list head for the expiry list will go away later once the expiry is moved into task work context. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1908272129220.1939@nanos.tec.linutronix.de
| * | | posix-cpu-timers: Move state tracking to struct posix_cputimersThomas Gleixner2019-08-281-33/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Put it where it belongs and clean up the ifdeffery in fork completely. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190821192922.743229404@linutronix.de
| * | | posix-cpu-timers: Deduplicate rlimit handlingThomas Gleixner2019-08-281-42/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Both thread and process expiry functions have the same functionality for sending signals for soft and hard RLIMITs duplicated in 4 different ways. Split it out into a common function and cleanup the callsites. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lkml.kernel.org/r/20190821192922.653276779@linutronix.de
| * | | posix-cpu-timers: Remove pointless comparisonsThomas Gleixner2019-08-281-9/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The soft RLIMIT expiry code checks whether the soft limit is greater than the hard limit. That's pointless because if the soft RLIMIT is greater than the hard RLIMIT then that code cannot be reached as the hard RLIMIT check is before that and already killed the process. Remove it. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lkml.kernel.org/r/20190821192922.548747613@linutronix.de
| * | | posix-cpu-timers: Get rid of 64bit divisionsThomas Gleixner2019-08-281-10/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of dividing A to match the units of B it's more efficient to multiply B to match the units of A. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lkml.kernel.org/r/20190821192922.458286860@linutronix.de
| * | | posix-cpu-timers: Consolidate timer expiry furtherThomas Gleixner2019-08-281-33/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With the array based samples and expiry cache, the expiry function can use a loop to collect timers from the clock specific lists. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lkml.kernel.org/r/20190821192922.365469982@linutronix.de
| * | | posix-cpu-timers: Get rid of zero checksThomas Gleixner2019-08-281-23/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Deactivation of the expiry cache is done by setting all clock caches to 0. That requires to have a check for zero in all places which update the expiry cache: if (cache == 0 || new < cache) cache = new; Use U64_MAX as the deactivated value, which allows to remove the zero checks when updating the cache and reduces it to the obvious check: if (new < cache) cache = new; This also removes the weird workaround in do_prlimit() which was required to convert a RLIMIT_CPU value of 0 (immediate expiry) to 1 because handing in 0 to the posix CPU timer code would have effectively disarmed it. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lkml.kernel.org/r/20190821192922.275086128@linutronix.de
| * | | posix-cpu-timers: Respect INFINITY for hard RTTIME limitThomas Gleixner2019-08-281-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The RTIME limit expiry code does not check the hard RTTIME limit for INFINITY, i.e. being disabled. Add it. While this could be considered an ABI breakage if something would depend on this behaviour. Though it's highly unlikely to have an effect because RLIM_INFINITY is at minimum INT_MAX and the RTTIME limit is in seconds, so the timer would fire after ~68 years. Adding this obvious correct limit check also allows further consolidation of that code and is a prerequisite for cleaning up the 0 based checks and the rlimit setter code. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lkml.kernel.org/r/20190821192922.078293002@linutronix.de
| * | | posix-cpu-timers: Switch thread group sampling to arrayThomas Gleixner2019-08-282-67/+48
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | That allows more simplifications in various places. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lkml.kernel.org/r/20190821192921.988426956@linutronix.de
| * | | posix-cpu-timers: Restructure expiry arrayThomas Gleixner2019-08-281-49/+56
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that the abused struct task_cputime is gone, it's more natural to bundle the expiry cache and the list head of each clock into a struct and have an array of those structs. Follow the hrtimer naming convention of 'bases' and rename the expiry cache to 'nextevt' and adapt all usage sites. Generates also better code .text size shrinks by 80 bytes. Suggested-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1908262021140.1939@nanos.tec.linutronix.de
| * | | posix-cpu-timers: Remove cputime_expiresThomas Gleixner2019-08-281-10/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The last users of the magic struct cputime based expiry cache are gone. Remove the leftovers. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lkml.kernel.org/r/20190821192921.790209622@linutronix.de
| * | | posix-cpu-timers: Make expiry checks array basedThomas Gleixner2019-08-281-49/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The expiry cache is an array indexed by clock ids. The new sample functions allow to retrieve a corresponding array of samples. Convert the fastpath expiry checks to make use of the new sample functions and do the comparisons on the sample and the expiry array. Make the check for the expiry array being zero array based as well. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lkml.kernel.org/r/20190821192921.695481430@linutronix.de
| * | | posix-cpu-timers: Provide array based sample functionsThomas Gleixner2019-08-281-0/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of using task_cputime and doing the addition of utime and stime at all call sites, it's way simpler to have a sample array which allows indexed based checks against the expiry cache array. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lkml.kernel.org/r/20190821192921.590362974@linutronix.de
| * | | posix-cpu-timers: Switch check_*_timers() to array cacheThomas Gleixner2019-08-281-15/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use the array based expiry cache in check_thread_timers() and convert the store in check_process_timers() for consistency. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lkml.kernel.org/r/20190821192921.408222378@linutronix.de
| * | | posix-cpu-timers: Simplify set_process_cpu_timer()Thomas Gleixner2019-08-281-16/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The expiry cache can now be accessed as an array. Replace the per clock checks with a simple comparison of the clock indexed array member. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lkml.kernel.org/r/20190821192921.303316423@linutronix.de
| * | | posix-cpu-timers: Simplify timer queueingThomas Gleixner2019-08-281-34/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that the expiry cache can be accessed as an array, the per clock checking can be reduced to just comparing the corresponding array elements. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lkml.kernel.org/r/20190821192921.212129449@linutronix.de
| * | | posix-cpu-timers: Provide array based access to expiry cacheThomas Gleixner2019-08-281-1/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Using struct task_cputime for the expiry cache is a pretty odd choice and comes with magic defines to rename the fields for usage in the expiry cache. struct task_cputime is basically a u64 array with 3 members, but it has distinct members. The expiry cache content is different than the content of task_cputime because expiry[PROF] = task_cputime.stime + task_cputime.utime expiry[VIRT] = task_cputime.utime expiry[SCHED] = task_cputime.sum_exec_runtime So there is no direct mapping between task_cputime and the expiry cache and the #define based remapping is just a horrible hack. Having the expiry cache array based allows further simplification of the expiry code. To avoid an all in one cleanup which is hard to review add a temporary anonymous union into struct task_cputime which allows array based access to it. That requires to reorder the members. Add a build time sanity check to validate that the members are at the same place. The union and the build time checks will be removed after conversion. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lkml.kernel.org/r/20190821192921.105793824@linutronix.de
| * | | posix-cpu-timers: Move expiry cache into struct posix_cputimersThomas Gleixner2019-08-281-18/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The expiry cache belongs into the posix_cputimers container where the other cpu timers information is. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lkml.kernel.org/r/20190821192921.014444012@linutronix.de
| * | | posix-cpu-timers: Create a container structThomas Gleixner2019-08-281-10/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Per task/process data of posix CPU timers is all over the place which makes the code hard to follow and requires ifdeffery. Create a container to hold all this information in one place, so data is consolidated and the ifdeffery can be confined to the posix timer header file and removed from places like fork. As a first step, move the cpu_timers list head array into the new struct and clean up the initializers and simplify fork. The remaining #ifdef in fork will be removed later. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lkml.kernel.org/r/20190821192920.819418976@linutronix.de
| * | | posix-cpu-timers: Move prof/virt_ticks into callerThomas Gleixner2019-08-281-21/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The functions have only one caller left. No point in having them. Move the almost duplicated code into the caller and simplify it. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lkml.kernel.org/r/20190821192920.729298382@linutronix.de
| * | | posix-cpu-timers: Sample task times once in expiry checkThomas Gleixner2019-08-281-4/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Sampling the task times twice does not make sense. Do it once. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lkml.kernel.org/r/20190821192920.639878168@linutronix.de
| * | | posix-cpu-timers: Get rid of pointer indirectionThomas Gleixner2019-08-281-28/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that the sample functions have no return value anymore, the result can simply be returned instead of using pointer indirection. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lkml.kernel.org/r/20190821192920.535079278@linutronix.de
| * | | posix-cpu-timers: Simplify sample functionsThomas Gleixner2019-08-281-15/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | All callers hand in a valdiated clock id. Remove the return value which was unchecked in most places anyway. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lkml.kernel.org/r/20190821192920.430475832@linutronix.de
| * | | posix-cpu-timers: Remove pointless return value checkThomas Gleixner2019-08-281-3/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | set_process_cpu_timer() checks already whether the clock id is valid. No point in checking the return value of the sample function. That allows to simplify the sample function later. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lkml.kernel.org/r/20190821192920.339725769@linutronix.de
| * | | posix-cpu-timers: Use clock ID in posix_cpu_timer_rearm()Thomas Gleixner2019-08-281-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Extract the clock ID (PROF/VIRT/SCHED) from the clock selector and use it as argument to the sample functions. That allows to simplify them once all callers are fixed. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lkml.kernel.org/r/20190821192920.245357769@linutronix.de
| * | | posix-cpu-timers: Use clock ID in posix_cpu_timer_get()Thomas Gleixner2019-08-281-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Extract the clock ID (PROF/VIRT/SCHED) from the clock selector and use it as argument to the sample functions. That allows to simplify them once all callers are fixed. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lkml.kernel.org/r/20190821192920.155487201@linutronix.de
| * | | posix-cpu-timers: Use clock ID in posix_cpu_timer_set()Thomas Gleixner2019-08-281-5/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Extract the clock ID (PROF/VIRT/SCHED) from the clock selector and use it as argument to the sample functions. That allows to simplify them once all callers are fixed. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lkml.kernel.org/r/20190821192920.050770464@linutronix.de
| * | | posix-cpu-timers: Consolidate thread group sample codeThomas Gleixner2019-08-281-39/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | cpu_clock_sample_group() and cpu_timer_sample_group() are almost the same. Before the rename one called thread_group_cputimer() and the other thread_group_cputime(). Really intuitive function names. Consolidate the functions and also avoid the thread traversal when the thread group's accounting is already active. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lkml.kernel.org/r/20190821192919.960966884@linutronix.de
| * | | posix-cpu-timers: Rename thread_group_cputimer() and make it staticThomas Gleixner2019-08-281-2/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | thread_group_cputimer() is a complete misnomer. The function does two things: - For arming process wide timers it makes sure that the atomic time storage is up to date. If no cpu timer is armed yet, then the atomic time storage is not updated by the scheduler for performance reasons. In that case a full summing up of all threads needs to be done and the update needs to be enabled. - Samples the current time into the caller supplied storage. Rename it to thread_group_start_cputime(), make it static and fixup the callsite. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lkml.kernel.org/r/20190821192919.869350319@linutronix.de
| * | | posix-cpu-timers: Sample directly in timer checkThomas Gleixner2019-08-281-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The thread group accounting is active, otherwise the expiry function would not be running. Sample the thread group time directly. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lkml.kernel.org/r/20190821192919.780348088@linutronix.de
| * | | itimers: Use quick sample functionThomas Gleixner2019-08-281-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | get_itimer() locks sighand lock and checks whether the timer is already expired. If it is not expired then the thread group cputime accounting is already enabled. Use the sampling function not the one which is meant for starting a timer. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lkml.kernel.org/r/20190821192919.689713638@linutronix.de
| * | | posix-cpu-timers: Provide quick sample function for itimerThomas Gleixner2019-08-281-0/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | get_itimer() needs a sample of the current thread group cputime. It invokes thread_group_cputimer() - which is a misnomer. That function also starts eventually the group cputime accouting which is bogus because the accounting is already active when a timer is armed. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lkml.kernel.org/r/20190821192919.599658199@linutronix.de
| * | | posix-cpu-timers: Use common permission check in posix_cpu_timer_create()Thomas Gleixner2019-08-281-32/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Yet another copy of the same thing gone... Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lkml.kernel.org/r/20190821192919.505833418@linutronix.de
| * | | posix-cpu-timers: Use common permission check in posix_cpu_clock_get()Thomas Gleixner2019-08-281-43/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Replace the next slightly different copy of permission checks. That also removes the necessarity to check the return value of the sample functions because the clock id is already validated. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lkml.kernel.org/r/20190821192919.414813172@linutronix.de
| * | | posix-cpu-timers: Provide task validation functionsThomas Gleixner2019-08-281-21/+44
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The code contains three slightly different copies of validating whether a given clock resolves to a valid task and whether the current caller has permissions to access it. Create central functions. Replace check_clock() as a first step and rename it to something sensible. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190821192919.326097175@linutronix.de
| * | | posix-cpu-timers: Remove tsk argument from run_posix_cpu_timers()Thomas Gleixner2019-08-212-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It's always current. Don't give people wrong ideas. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lkml.kernel.org/r/20190819143801.945469967@linutronix.de
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