2024 Clocksource

Clocksource_watchdog

Author: khhi

August undefined, 2024

WebMar 22, 2024 · Clocksource watchdog has been found responsible for generating latency spikes (in the 10-20 us range) when woken up to check for TSC stability. Add an option to disable it at boot. Signed-off-by: Juri Lelli Signed-off-by: Thomas Gleixner WebOn Sun, Dec 05, 2024 at 10:38:15PM -0500, Waiman Long wrote: > A watchdog maximum skew of 100us may still be too small for > some systems or archs. It may also be too small when some kernel > debug config options are enabled. So add a new Kconfig option > CLOCKSOURCE_WATCHDOG_MAX_SKEW_US to allow kernel builders to have more …

[PATCH 4.4 114/192] [PATCH 118/135] clocksource: Allow …

WebSpecify the maximum amount of allowable watchdog skew in microseconds before reporting the clocksource to be unstable. The default is based on a half-second … WebRed Hat Customer Portal - Access to 24x7 support and knowledge. Focus mode. Chapter 15. Timestamping. 15.1. Hardware Clocks. Multiprocessor systems such as NUMA or SMP have multiple instances of clock sources. The way clocks interact among themselves and the way they react to system events, such as CPU frequency scaling or entering energy ... book a trip to dry tortugas

[SOLVED] clocksource: timekeeping watchdog on CPU1: …

WebMay 20, 2024 · root@LFS:# clocksource: timekeeping watchdog on CPU0: acpi_pm wd-wd readback delay of 643744ns clocksource: wd-tsc-wd read-back delay of 182144ns, … Web* the watchdog marked the clocksource unstable * @tick_stable: Optional function called periodically from the watchdog * code to provide stable synchronization points * @wd_list: List head to enqueue into the watchdog list (internal) * @cs_last: Last clocksource value for clocksource watchdog ... Webdepends on CLOCKSOURCE_WATCHDOG: range 50 1000: default 125: help: Specify the maximum amount of allowable watchdog skew in: microseconds before reporting the … godly science

linux/clocksource.h at master · torvalds/linux · GitHub

clocksource报错 · Issue #9028 · coolsnowwolf/lede · GitHub

WebOne observed example is on a Intel Baytrail platform where TSC > is the main clocksource, HPET is disabled due to a hardware bug and acpi_pm > gets selected as the watchdog clocksource. > > Calculate the maximum number of nanoseconds the watchdog clocksource can > represent without overflow and do not disqualify the main … Web[ 2685.867873] clocksource: timekeeping watchdog on CPU117: hpet read-back delay of 57269ns, attempt 4, marking unstable [46215.471228] clocksource: timekeeping watchdog on CPU8: hpet read-back delay of 61460ns, attempt 4, marking unstable Commit 2e27e793e280 ("clocksource: Reduce clocksource-skew threshold"), godlysecurity.comWebJul 11, 2024 · clocksource: timekeeping watchdog on CPU0: Marking clocksource 'tsc' as unstable because the skew is too large: clocksource: 'acpi_pm' wd_now: 74c6dd wd_last: 8dd916 mask: ffffff clocksource: 'tsc' cs_now: 119ac91c7b1 cs_last: 1158a25441d mask: ffffffffffffffff clocksource: Switched to clocksource acpi_pm godly security agency

"WebA clocksource can be removed unconditionally even if there is no fallback clocksource available. clocksources in a module can be removed as well. Aside of that the registration part lacks a few sanity checks as well. The clockevents layer does not allow unregistration, but for reconfigurable hardware this is a must have feature. " - Clocksource_watchdog

Clocksource_watchdog

[PATCH 0/7] jz4740 watchdog driver & platform cleanups

WebIt's interesting to note that no patches or proposals have been made to solve the way the Linux kernel's clocksource watchdog decides what clocksource is "reliable". Coffee Lake's broken HPET reveals that if the HPET clocksource is drifting and the TSC is fine the kernel will decide that using the HPET is the best option. Disabling the HPET on ... WebIssue. Soft lockup occurs with below logs: Raw. [15013187.660325] CPU6 has been hot-added [15013187.663126] CPU7 has been hot-added [15013187.663454] CPU8 has been hot-added [15013187.663927] CPU9 has been hot-added [15013187.673920] smpboot: Booting Node 0 Processor 7 APIC 0x7 [15013188.089777] kvm-clock: cpu 7, msr …

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Web[ 1.450918] clocksource: timekeeping watchdog on CPU1: Marking clocksource 'tsc' as unstable because the skew is too large: [ 1.451183] clocksource: 'refined-jiffies' wd_now: ffff8bcd wd_last: ffff8b9b mask: ffffffff [ 1.451332] clocksource: 'tsc' cs_now: ac1cfb3e87236 cs_last: ac1cfae8d5893 mask: ffffffffffffffff ... WebFeb 13, 2024 · CLOCKSOURCE_WATCHDOG_MAX_SKEW_US Kconfig option to 125 microseconds of skew per second, resulting in 500 microseconds of skew per second in …

WebThis is the clocksource with the highest rating and thus it becomes the watchdog making unloading of the vmbus module impossible. Separate clocksource_select_watchdog() from clocksource_enqueue_watchdog() and use it on clocksource register/rating change/unregister. After all, lobotomized monkeys may need some love too.

WebAnd it > is not necessarily a bad thing for the kernel to diagnose cases where > high-stress workloads are being run on hardware that is not designed > for this sort of use. > > … Web[ 2685.867873] clocksource: timekeeping watchdog on CPU117: hpet read-back delay of 57269ns, attempt 4, marking unstable [46215.471228] clocksource: timekeeping …

WebSo.. if the clocksource you want to unbind is the highest rated continuous clocksource that doesn't need a watchdog (basically what's likely to be in-use and required to be unbinded), its likely to be selected as the watchdog already. ie: on a system that has only HPET/ACPI_PM, you can't unbind HPET, since its a watchdog.

WebSince Kernel 5.14.X I would get clocksource watchdog errors and my PC automatically switching to HPET. This is due to upstream kernel changes that imposed much stricter limits on allowed TSC jitter and clock deviation between different CPU cores. It caused repeated attempts to retry at syncing them to timeout aswell. book a trip to londonWebIf the clocksource which should be unbound is the current clocksource and no fallback can be found, unbind returns -EBUSY. This does not support the unbinding of a clocksource which is used as the watchdog clocksource. … godly seedWebIf CPU is very busy during boot, the watchdog clocksource may not be read frequently enough, resulting in a large difference that is treated as "negative" by clocksource_delta() and incorrectly truncated to 0. This false alarm causes TSC to be declared unstable: clocksource: timekeeping watchdog on CPU1: Marking clocksource book a trip to indiaWebAug 9, 2024 · Probably solved the issue: by setting the tsc=unstable kernel boot parameter, and re-enabling HPET in the UEFI/BIOS, the Linux kernel decided to use hpet as … book a trip to irelandWebLKML Archive on lore.kernel.org help / color / mirror / Atom feed * [PATCH 0/4] clocksource: remove obsolete drivers @ 2024-01-20 13:15 Arnd Bergmann 2024-01-20 13:15 ` [PATCH 1/4] timer: remove u300 driver Arnd Bergmann ` (4 more replies) 0 siblings, 5 replies; 16+ messages in thread From: Arnd Bergmann @ 2024-01-20 13:15 UTC … book a trip to myrtle beachWebFeb 8, 2024 · [ 2.102993] tsc: Marking TSC unstable due to clocksource watchdog [ 2.103482] clocksource: Checking clocksource tsc synchronization from CPU 6 to … godly screensaversWebJan 24, 2024 · Given that the clocksource watchdog is a continual diagnostic check with frequency of twice a second, there is no need to rush it when the system is under heavy load. Therefore, when high clocksource read latencies are detected, suspend the watchdog timer for 5 minutes. book a trip to hawaii in 2023