BMC/Intel-BMC/linux.git/kernel/time, branch v4.18.11

clocksource: Revert "Remove kthread"

2018-09-19T20:41:37+00:00

commit e2c631ba75a7e727e8db0a9d30a06bfd434adb3a upstream. I turns out that the silly spawn kthread from worker was actually needed. clocksource_watchdog_kthread() cannot be called directly from clocksource_watchdog_work(), because clocksource_select() calls timekeeping_notify() which uses stop_machine(). One cannot use stop_machine() from a workqueue() due lock inversions wrt CPU hotplug. Revert the patch but add a comment that explain why we jump through such apparently silly hoops. Fixes: 7197e77abcb6 ("clocksource: Remove kthread") Reported-by: Siegfried Metz Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Thomas Gleixner Tested-by: Niklas Cassel Tested-by: Kevin Shanahan Tested-by: viktor_jaegerskuepper@freenet.de Tested-by: Siegfried Metz Cc: rafael.j.wysocki@intel.com Cc: len.brown@intel.com Cc: diego.viola@gmail.com Cc: rui.zhang@intel.com Cc: bjorn.andersson@linaro.org Link: https://lkml.kernel.org/r/20180905084158.GR24124@hirez.programming.kicks-ass.net Cc: Siegfried Metz Signed-off-by: Greg Kroah-Hartman

timers: Clear timer_base::must_forward_clk with timer_base::lock held

2018-09-19T20:41:26+00:00

[ Upstream commit 363e934d8811d799c88faffc5bfca782fd728334 ] timer_base::must_forward_clock is indicating that the base clock might be stale due to a long idle sleep. The forwarding of the base clock takes place in the timer softirq or when a timer is enqueued to a base which is idle. If the enqueue of timer to an idle base happens from a remote CPU, then the following race can happen: CPU0 CPU1 run_timer_softirq mod_timer base = lock_timer_base(timer); base->must_forward_clk = false if (base->must_forward_clk) forward(base); -> skipped enqueue_timer(base, timer, idx); -> idx is calculated high due to stale base unlock_timer_base(timer); base = lock_timer_base(timer); forward(base); The root cause is that timer_base::must_forward_clk is cleared outside the timer_base::lock held region, so the remote queuing CPU observes it as cleared, but the base clock is still stale. This can cause large granularity values for timers, i.e. the accuracy of the expiry time suffers. Prevent this by clearing the flag with timer_base::lock held, so that the forwarding takes place before the cleared flag is observable by a remote CPU. Signed-off-by: Gaurav Kohli Signed-off-by: Thomas Gleixner Cc: john.stultz@linaro.org Cc: sboyd@kernel.org Cc: linux-arm-msm@vger.kernel.org Link: https://lkml.kernel.org/r/1533199863-22748-1-git-send-email-gkohli@codeaurora.org Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

nohz: Fix local_timer_softirq_pending()

2018-07-31T20:08:44+00:00

local_timer_softirq_pending() checks whether the timer softirq is pending with: local_softirq_pending() & TIMER_SOFTIRQ. This is wrong because TIMER_SOFTIRQ is the softirq number and not a bitmask. So the test checks for the wrong bit. Use BIT(TIMER_SOFTIRQ) instead. Fixes: 5d62c183f9e9 ("nohz: Prevent a timer interrupt storm in tick_nohz_stop_sched_tick()") Signed-off-by: Anna-Maria Gleixner Signed-off-by: Thomas Gleixner Reviewed-by: Paul E. McKenney Reviewed-by: Daniel Bristot de Oliveira Acked-by: Frederic Weisbecker Cc: bigeasy@linutronix.de Cc: peterz@infradead.org Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20180731161358.29472-1-anna-maria@linutronix.de

Revert "tick: Prefer a lower rating device only if it's CPU local device"

2018-07-10T20:12:47+00:00

This reverts commit 1332a90558013ae4242e3dd7934bdcdeafb06c0d. The original issue was not because of incorrect checking of cpumask for both new and old tick device. It was incorrectly analysed was due to the misunderstanding of the comment and misinterpretation of the return value from tick_check_preferred. The main issue is with the clockevent driver that sets the cpumask to cpu_all_mask instead of cpu_possible_mask. Signed-off-by: Sudeep Holla Signed-off-by: Thomas Gleixner Tested-by: Kevin Hilman Tested-by: Martin Blumenstingl Cc: linux-arm-kernel@lists.infradead.org Cc: Marc Zyngier Link: https://lkml.kernel.org/r/1531151136-18297-1-git-send-email-sudeep.holla@arm.com

time: Make sure jiffies_to_msecs() preserves non-zero time periods

2018-06-22T15:48:36+00:00

For the common cases where 1000 is a multiple of HZ, or HZ is a multiple of 1000, jiffies_to_msecs() never returns zero when passed a non-zero time period. However, if HZ > 1000 and not an integer multiple of 1000 (e.g. 1024 or 1200, as used on alpha and DECstation), jiffies_to_msecs() may return zero for small non-zero time periods. This may break code that relies on receiving back a non-zero value. jiffies_to_usecs() does not need such a fix: one jiffy can only be less than one µs if HZ > 1000000, and such large values of HZ are already rejected at build time, twice: - include/linux/jiffies.h does #error if HZ >= 12288, - kernel/time/time.c has BUILD_BUG_ON(HZ > USEC_PER_SEC). Broken since forever. Signed-off-by: Geert Uytterhoeven Signed-off-by: Thomas Gleixner Reviewed-by: Arnd Bergmann Cc: John Stultz Cc: Stephen Boyd Cc: linux-alpha@vger.kernel.org Cc: linux-mips@linux-mips.org Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20180622143357.7495-1-geert@linux-m68k.org

posix-timers: Fix nanosleep_copyout() for CONFIG_COMPAT_32BIT_TIME

2018-06-19T07:23:19+00:00

Commit b5793b0d92c9 added support for building the nanosleep compat system call on 32-bit architectures, but missed one change in nanosleep_copyout(), which would trigger a BUG() as soon as any architecture is switched over to use it. Use the proper config symbol to enable the code path. Fixes: Commit b5793b0d92c9 ("posix-timers: Make compat syscalls depend on CONFIG_COMPAT_32BIT_TIME") Signed-off-by: Arnd Bergmann Signed-off-by: Thomas Gleixner Cc: y2038@lists.linaro.org Cc: Anna-Maria Gleixner Cc: Deepa Dinamani Cc: "Rafael J. Wysocki" Link: https://lkml.kernel.org/r/20180618140811.2998503-1-arnd@arndb.de

posix-cpu-timers: Remove lockdep_assert_irqs_disabled()

2018-06-12T15:18:37+00:00

The lockdep_assert_irqs_disabled() was a BUG_ON() statement in the beginning and it was added just before the "spin_lock(siglock)" statement to ensure this lock was taken with disabled interrupts. This is no longer the case: the siglock is acquired via lock_task_sighand() and this function already disables the interrupts. The lock is also acquired before this "lockdep_assert_irqs_disabled" so it is best to remove it. Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Thomas Gleixner Cc: Frederic Weisbecker Link: https://lkml.kernel.org/r20180504152548.7166-1-bigeasy@linutronix.de

Merge tag 'pm-4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

2018-06-05T16:38:39+00:00

Pull power management updates from Rafael Wysocki: "These include a significant update of the generic power domains (genpd) and Operating Performance Points (OPP) frameworks, mostly related to the introduction of power domain performance levels, cpufreq updates (new driver for Qualcomm Kryo processors, updates of the existing drivers, some core fixes, schedutil governor improvements), PCI power management fixes, ACPI workaround for EC-based wakeup events handling on resume from suspend-to-idle, and major updates of the turbostat and pm-graph utilities. Specifics: - Introduce power domain performance levels into the the generic power domains (genpd) and Operating Performance Points (OPP) frameworks (Viresh Kumar, Rajendra Nayak, Dan Carpenter). - Fix two issues in the runtime PM framework related to the initialization and removal of devices using device links (Ulf Hansson). - Clean up the initialization of drivers for devices in PM domains (Ulf Hansson, Geert Uytterhoeven). - Fix a cpufreq core issue related to the policy sysfs interface causing CPU online to fail for CPUs sharing one cpufreq policy in some situations (Tao Wang). - Make it possible to use platform-specific suspend/resume hooks in the cpufreq-dt driver and make the Armada 37xx DVFS use that feature (Viresh Kumar, Miquel Raynal). - Optimize policy transition notifications in cpufreq (Viresh Kumar). - Improve the iowait boost mechanism in the schedutil cpufreq governor (Patrick Bellasi). - Improve the handling of deferred frequency updates in the schedutil cpufreq governor (Joel Fernandes, Dietmar Eggemann, Rafael Wysocki, Viresh Kumar). - Add a new cpufreq driver for Qualcomm Kryo (Ilia Lin). - Fix and clean up some cpufreq drivers (Colin Ian King, Dmitry Osipenko, Doug Smythies, Luc Van Oostenryck, Simon Horman, Viresh Kumar). - Fix the handling of PCI devices with the DPM_SMART_SUSPEND flag set and update stale comments in the PCI core PM code (Rafael Wysocki). - Work around an issue related to the handling of EC-based wakeup events in the ACPI PM core during resume from suspend-to-idle if the EC has been put into the low-power mode (Rafael Wysocki). - Improve the handling of wakeup source objects in the PM core (Doug Berger, Mahendran Ganesh, Rafael Wysocki). - Update the driver core to prevent deferred probe from breaking suspend/resume ordering (Feng Kan). - Clean up the PM core somewhat (Bjorn Helgaas, Ulf Hansson, Rafael Wysocki). - Make the core suspend/resume code and cpufreq support the RT patch (Sebastian Andrzej Siewior, Thomas Gleixner). - Consolidate the PM QoS handling in cpuidle governors (Rafael Wysocki). - Fix a possible crash in the hibernation core (Tetsuo Handa). - Update the rockchip-io Adaptive Voltage Scaling (AVS) driver (David Wu). - Update the turbostat utility (fixes, cleanups, new CPU IDs, new command line options, built-in "Low Power Idle" counters support, new POLL and POLL% columns) and add an entry for it to MAINTAINERS (Len Brown, Artem Bityutskiy, Chen Yu, Laura Abbott, Matt Turner, Prarit Bhargava, Srinivas Pandruvada). - Update the pm-graph to version 5.1 (Todd Brandt). - Update the intel_pstate_tracer utility (Doug Smythies)" * tag 'pm-4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (128 commits) tools/power turbostat: update version number tools/power turbostat: Add Node in output tools/power turbostat: add node information into turbostat calculations tools/power turbostat: remove num_ from cpu_topology struct tools/power turbostat: rename num_cores_per_pkg to num_cores_per_node tools/power turbostat: track thread ID in cpu_topology tools/power turbostat: Calculate additional node information for a package tools/power turbostat: Fix node and siblings lookup data tools/power turbostat: set max_num_cpus equal to the cpumask length tools/power turbostat: if --num_iterations, print for specific number of iterations tools/power turbostat: Add Cannon Lake support tools/power turbostat: delete duplicate #defines x86: msr-index.h: Correct SNB_C1/C3_AUTO_UNDEMOTE defines tools/power turbostat: Correct SNB_C1/C3_AUTO_UNDEMOTE defines tools/power turbostat: add POLL and POLL% column tools/power turbostat: Fix --hide Pk%pc10 tools/power turbostat: Build-in "Low Power Idle" counters support tools/power turbostat: Don't make man pages executable tools/power turbostat: remove blank lines tools/power turbostat: a small C-states dump readability immprovement ...

Merge branch 'timers-2038-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2018-06-05T04:02:18+00:00

Pull time/Y2038 updates from Thomas Gleixner: - Consolidate SySV IPC UAPI headers - Convert SySV IPC to the new COMPAT_32BIT_TIME mechanism - Cleanup the core interfaces and standardize on the ktime_get_* naming convention. - Convert the X86 platform ops to timespec64 - Remove the ugly temporary timespec64 hack * 'timers-2038-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (22 commits) x86: Convert x86_platform_ops to timespec64 timekeeping: Add more coarse clocktai/boottime interfaces timekeeping: Add ktime_get_coarse_with_offset timekeeping: Standardize on ktime_get_*() naming timekeeping: Clean up ktime_get_real_ts64 timekeeping: Remove timespec64 hack y2038: ipc: Redirect ipc(SEMTIMEDOP, ...) to compat_ksys_semtimedop y2038: ipc: Enable COMPAT_32BIT_TIME y2038: ipc: Use __kernel_timespec y2038: ipc: Report long times to user space y2038: ipc: Use ktime_get_real_seconds consistently y2038: xtensa: Extend sysvipc data structures y2038: powerpc: Extend sysvipc data structures y2038: sparc: Extend sysvipc data structures y2038: parisc: Extend sysvipc data structures y2038: mips: Extend sysvipc data structures y2038: arm64: Extend sysvipc compat data structures y2038: s390: Remove unneeded ipc uapi header files y2038: ia64: Remove unneeded ipc uapi header files y2038: alpha: Remove unneeded ipc uapi header files ...

Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2018-06-05T03:27:54+00:00

Pull timers and timekeeping updates from Thomas Gleixner: - Core infrastucture work for Y2038 to address the COMPAT interfaces: + Add a new Y2038 safe __kernel_timespec and use it in the core code + Introduce config switches which allow to control the various compat mechanisms + Use the new config switch in the posix timer code to control the 32bit compat syscall implementation. - Prevent bogus selection of CPU local clocksources which causes an endless reselection loop - Remove the extra kthread in the clocksource code which has no value and just adds another level of indirection - The usual bunch of trivial updates, cleanups and fixlets all over the place - More SPDX conversions * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits) clocksource/drivers/mxs_timer: Switch to SPDX identifier clocksource/drivers/timer-imx-tpm: Switch to SPDX identifier clocksource/drivers/timer-imx-gpt: Switch to SPDX identifier clocksource/drivers/timer-imx-gpt: Remove outdated file path clocksource/drivers/arc_timer: Add comments about locking while read GFRC clocksource/drivers/mips-gic-timer: Add pr_fmt and reword pr_* messages clocksource/drivers/sprd: Fix Kconfig dependency clocksource: Move inline keyword to the beginning of function declarations timer_list: Remove unused function pointer typedef timers: Adjust a kernel-doc comment tick: Prefer a lower rating device only if it's CPU local device clocksource: Remove kthread time: Change nanosleep to safe __kernel_* types time: Change types to new y2038 safe __kernel_* types time: Fix get_timespec64() for y2038 safe compat interfaces time: Add new y2038 safe __kernel_timespec posix-timers: Make compat syscalls depend on CONFIG_COMPAT_32BIT_TIME time: Introduce CONFIG_COMPAT_32BIT_TIME time: Introduce CONFIG_64BIT_TIME in architectures compat: Enable compat_get/put_timespec64 always ...