From: Thomas Gleixner Date: Tue, 9 Jun 2026 15:14:45 +0000 (+0200) Subject: time/jiffies: Register jiffies clocksource before usage X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=f24df84cbe05e4471c04ac4b921fc0340bbc7752;p=thirdparty%2Fkernel%2Flinux.git time/jiffies: Register jiffies clocksource before usage Teddy reported that a XEN HVM has a long boot delay, which was bisected to the recent enhancements to the negative motion detection. It turned out that the jiffies clocksource is used in early boot before it is registered, which leaves the max_delta_raw field at zero. That causes the read out to be clamped to the max delta of 0, which means time is not making progress. Cure it by ensuring that it is initialized before its first usage in timekeeping_init(). Fixes: 76031d9536a0 ("clocksource: Make negative motion detection more robust") Reported-by: Teddy Astie Signed-off-by: Thomas Gleixner Tested-by: Teddy Astie Cc: stable@vger.kernel.org Link: https://patch.msgid.link/87y0gn3fve.ffs@fw13 Closes: https://lore.kernel.org/all/1780914594.8631fc262581453bbf619ec5b2062170.19ea6c8227b000701b@vates.tech --- diff --git a/kernel/time/jiffies.c b/kernel/time/jiffies.c index 1c954f330dfe..d51428867a33 100644 --- a/kernel/time/jiffies.c +++ b/kernel/time/jiffies.c @@ -60,15 +60,14 @@ EXPORT_SYMBOL(get_jiffies_64); EXPORT_SYMBOL(jiffies); -static int __init init_jiffies_clocksource(void) -{ - return __clocksource_register(&clocksource_jiffies); -} - -core_initcall(init_jiffies_clocksource); +static bool cs_jiffies_registered __initdata; struct clocksource * __init __weak clocksource_default_clock(void) { + if (!cs_jiffies_registered) { + __clocksource_register(&clocksource_jiffies); + cs_jiffies_registered = true; + } return &clocksource_jiffies; }