Messages in this thread | | | Subject | Re: [PATCH] genirq/msi: Shutdown managed interrupts with unsatifiable affinities | From | Xiongfeng Wang <> | Date | Thu, 10 Mar 2022 11:24:10 +0800 |
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On 2022/3/9 18:20, John Garry wrote: > + > > On 07/03/2022 19:06, Marc Zyngier wrote: >> When booting with maxcpus=<small number>, interrupt controllers >> such as the GICv3 ITS may not be able to satisfy the affinity of >> some managed interrupts, as some of the HW resources are simply >> not available. >> >> In order to deal with this, do not try to activate such interrupt >> if there is no online CPU capable of handling it. Instead, place >> it in shutdown state. Once a capable CPU shows up, it will be >> activated. >> >> Reported-by: John Garry <john.garry@huawei.com> >> Reported-by: David Decotigny <ddecotig@google.com> >> Signed-off-by: Marc Zyngier <maz@kernel.org> > > Tested-by: John Garry <john.garry@huawei.com> > >> --- > > JFYI, I could not recreate the same crash reported in the original thread for > "nohz_full=5-127 isolcpus=nohz,domain,managed_irq,5-127 maxcpus=1". Here's just > showing what I set via cmdline:
I think it's the userspace online all the CPUs that cause the crash. Could you please try to online all the CPUs after boot.
Thanks, Xiongfeng
> > estuary:/$ dmesg | grep -i hz > [ 0.000000] Kernel command line: BOOT_IMAGE=/john/Image rdinit=/init > console=ttyS0,115200 no_console_suspend nvme.use_threaded_interrupts=0 > iommu.strict=0 acpi=force earlycon=pl011,mmio32,0x602b0000 nohz_full=5-127 > isolcpus=nohz,domain,managed_irq,5-127 maxcpus=1 > [ 0.000000] NO_HZ: Full dynticks CPUs: 5-127. > [ 0.000000] arch_timer: cp15 timer(s) running at 100.00MHz (phys). > [ 0.000000] sched_clock: 57 bits at 100MHz, resolution 10ns, wraps every > 4398046511100ns > [ 15.314258] sbsa-gwdt sbsa-gwdt.0: Initialized with 10s timeout @ 100000000 > Hz, action=0 > > And for the kernel build: > $ more .config | grep NO_HZ > CONFIG_NO_HZ_COMMON=y > # CONFIG_NO_HZ_IDLE is not set > CONFIG_NO_HZ_FULL=y > # CONFIG_NO_HZ is not set > $ > > Thanks, > John >> kernel/irq/msi.c | 12 ++++++++++++ >> 1 file changed, 12 insertions(+) >> >> diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c >> index 2bdfce5edafd..aa84ce84c2ec 100644 >> --- a/kernel/irq/msi.c >> +++ b/kernel/irq/msi.c >> @@ -818,6 +818,18 @@ static int msi_init_virq(struct irq_domain *domain, int >> virq, unsigned int vflag >> irqd_clr_can_reserve(irqd); >> if (vflags & VIRQ_NOMASK_QUIRK) >> irqd_set_msi_nomask_quirk(irqd); >> + >> + /* >> + * If the interrupt is managed but no CPU is available >> + * to service it, shut it down until better times. >> + */ >> + if ((vflags & VIRQ_ACTIVATE) && >> + irqd_affinity_is_managed(irqd) && >> + !cpumask_intersects(irq_data_get_affinity_mask(irqd), >> + cpu_online_mask)) { >> + irqd_set_managed_shutdown(irqd); >> + return 0; >> + } >> } >> if (!(vflags & VIRQ_ACTIVATE)) > > .
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