Messages in this thread Patch in this message | | | Subject | Re: WARNING: CPU: 0 PID: 0 at drivers/irqchip/irq-gic-v3-its.c | From | Marc Zyngier <> | Date | Fri, 9 Nov 2018 17:41:26 +0000 |
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On 09/11/18 17:28, Sudeep Holla wrote: > On Fri, Nov 9, 2018 at 4:10 PM Marc Zyngier <marc.zyngier@arm.com> wrote: >> > [...] > >> >> See bb42ca474010 and d003d029cea8 for details. >> >> Now, activating this workaround leads to lockdep being really angry, >> most likely because the cpus_read_lock is not taken, which is a change >> in behaviour... >> >> I'm trying to dig into this now. >> > > Yes we found similar issue in kernel/sched/core.c sched_init_smp > There's a fix with detailed description in -next > (Commit 40fa3780bac2 ("sched/core: Take the hotplug lock in sched_init_smp()") > > The behaviour changed since commit cb538267ea1e ("jump_label/lockdep: > Assert we hold the hotplug lock for _cpuslocked() operations")
I indeed came to the same conclusion, but the fix is slightly less than obvious. I have the following arm64-specific crap, but it is pretty terrible:
diff --git a/arch/arm64/kernel/time.c b/arch/arm64/kernel/time.c index f258636273c9..9e96e9eaca9b 100644 --- a/arch/arm64/kernel/time.c +++ b/arch/arm64/kernel/time.c @@ -36,6 +36,7 @@ #include <linux/clocksource.h> #include <linux/clk-provider.h> #include <linux/acpi.h> +#include <linux/cpu.h>
#include <clocksource/arm_arch_timer.h>
@@ -69,7 +70,9 @@ void __init time_init(void) u32 arch_timer_rate;
of_clk_init(NULL); + cpus_read_lock(); timer_probe(); + cpus_read_unlock();
tick_setup_hrtimer_broadcast();
Qian, can you please let me know if this helps? If it does, we'll have to think of something a bit better... Thanks,
M. -- Jazz is not dead. It just smells funny...
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