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Groups > linux.kernel > #1299431
| From | Thomas Gleixner <tglx@linutronix.de> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [Bugfix v2 4/5] x86/irq: Fix a race condition between vector assigning and cleanup |
| Date | 2015-12-30 18:30 +0100 |
| Message-ID | <qLsJs-15B-9@gated-at.bofh.it> (permalink) |
| References | <qHwsh-7Xj-15@gated-at.bofh.it> <qISqJ-2fv-3@gated-at.bofh.it> <qISqK-2fv-19@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Wed, 23 Dec 2015, Jiang Liu wrote:
> static void clear_irq_vector(int irq, struct apic_chip_data *data)
> {
> - struct irq_desc *desc;
> + struct irq_desc *desc = irq_to_desc(irq);
> int cpu, vector = data->cfg.vector;
>
> BUG_ON(!vector);
> @@ -236,10 +235,6 @@ static void clear_irq_vector(int irq, struct apic_chip_data *data)
> data->cfg.vector = 0;
> cpumask_clear(data->domain);
>
> - if (likely(!data->move_in_progress))
> - return;
Why are you removing this?
> -
> - desc = irq_to_desc(irq);
> for_each_cpu_and(cpu, data->old_domain, cpu_online_mask) {
> for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS;
> vector++) {
> @@ -421,10 +416,13 @@ static void __setup_vector_irq(int cpu)
> struct irq_data *idata = irq_desc_get_irq_data(desc);
>
> data = apic_chip_data(idata);
> - if (!data || !cpumask_test_cpu(cpu, data->domain))
> - continue;
> - vector = data->cfg.vector;
> - per_cpu(vector_irq, cpu)[vector] = desc;
> + if (data) {
> + cpumask_clear_cpu(cpu, data->old_domain);
Why would the newly online cpu be in data->old_domain?
> + if (cpumask_test_cpu(cpu, data->domain)) {
> + vector = data->cfg.vector;
> + per_cpu(vector_irq, cpu)[vector] = desc;
> + }
> + }
> @@ -563,14 +558,10 @@ asmlinkage __visible void smp_irq_move_cleanup_interrupt(void)
> goto unlock;
>
> /*
> - * Check if the irq migration is in progress. If so, we
> - * haven't received the cleanup request yet for this irq.
> + * Nothing to cleanup if this cpu is not set
> + * in the old_domain mask.
> */
> - if (data->move_in_progress)
> - goto unlock;
Removing this is broken. If data->move_in_progress is set, then you cannot
clear the vector. If there are two interrupt moves pending then the IPI of the
first one will clear the second one as well, which might be still targeted to
this cpu.
This whole patch set is way too complex. A lot of tiny changes here and there
and none of them is documented.
Thanks,
tglx
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Re: [lkp] [x86/irq] 4c24cee6b2: IP-Config: Auto-configuration of network failed Jiang Liu <jiang.liu@linux.intel.com> - 2015-12-14 07:40 +0100
Re: [LKP] [lkp] [x86/irq] 4c24cee6b2: IP-Config: Auto-configuration of network failed "Huang\, Ying" <ying.huang@intel.com> - 2015-12-14 08:00 +0100
Re: [LKP] [lkp] [x86/irq] 4c24cee6b2: IP-Config: Auto-configuration of network failed Borislav Petkov <bp@alien8.de> - 2015-12-14 11:00 +0100
Re: [LKP] [lkp] [x86/irq] 4c24cee6b2: IP-Config: Auto-configuration of network failed Jiang Liu <jiang.liu@linux.intel.com> - 2015-12-15 09:00 +0100
Re: [LKP] [lkp] [x86/irq] 4c24cee6b2: IP-Config: Auto-configuration of network failed Borislav Petkov <bp@alien8.de> - 2015-12-15 11:10 +0100
Re: [LKP] [lkp] [x86/irq] 4c24cee6b2: IP-Config: Auto-configuration of network failed Thomas Gleixner <tglx@linutronix.de> - 2015-12-19 21:40 +0100
[Bugfix v2 5/5] x86/irq: Trivial cleanups for x86 vector allocation code Jiang Liu <jiang.liu@linux.intel.com> - 2015-12-23 15:20 +0100
[Bugfix v2 1/5] x86/irq: Do not reuse struct apic_chip_data.old_domain as temporary buffer Jiang Liu <jiang.liu@linux.intel.com> - 2015-12-23 15:20 +0100
[Bugfix v2 3/5] x86/irq: Fix a race window in x86_vector_free_irqs() Jiang Liu <jiang.liu@linux.intel.com> - 2015-12-23 15:20 +0100
Re: [Bugfix v2 3/5] x86/irq: Fix a race window in x86_vector_free_irqs() Thomas Gleixner <tglx@linutronix.de> - 2015-12-29 14:50 +0100
[Bugfix v2 2/5] x86/irq: Enhance __assign_irq_vector() to rollback in case of failure Jiang Liu <jiang.liu@linux.intel.com> - 2015-12-23 15:20 +0100
Re: [Bugfix v2 2/5] x86/irq: Enhance __assign_irq_vector() to rollback in case of failure Thomas Gleixner <tglx@linutronix.de> - 2015-12-30 20:00 +0100
[Bugfix v2 4/5] x86/irq: Fix a race condition between vector assigning and cleanup Jiang Liu <jiang.liu@linux.intel.com> - 2015-12-23 15:20 +0100
Re: [Bugfix v2 4/5] x86/irq: Fix a race condition between vector assigning and cleanup Borislav Petkov <bp@alien8.de> - 2015-12-23 19:50 +0100
Re: [Bugfix v2 4/5] x86/irq: Fix a race condition between vector assigning and cleanup Thomas Gleixner <tglx@linutronix.de> - 2015-12-30 18:30 +0100
Re: [Bugfix v2 4/5] x86/irq: Fix a race condition between vector assigning and cleanup Thomas Gleixner <tglx@linutronix.de> - 2015-12-31 00:00 +0100
Re: [Bugfix v2 1/5] x86/irq: Do not reuse struct apic_chip_data.old_domain as temporary buffer Borislav Petkov <bp@alien8.de> - 2015-12-23 20:20 +0100
Re: [Bugfix v2 1/5] x86/irq: Do not reuse struct apic_chip_data.old_domain as temporary buffer Jeremiah Mahler <jmmahler@gmail.com> - 2015-12-24 06:20 +0100
Re: [Bugfix v2 1/5] x86/irq: Do not reuse struct apic_chip_data.old_domain as temporary buffer Jiang Liu <jiang.liu@linux.intel.com> - 2015-12-28 09:30 +0100
Re: [Bugfix v2 1/5] x86/irq: Do not reuse struct apic_chip_data.old_domain as temporary buffer Jeremiah Mahler <jmmahler@gmail.com> - 2015-12-29 04:30 +0100
Re: [Bugfix v2 1/5] x86/irq: Do not reuse struct apic_chip_data.old_domain as temporary buffer Joe Lawrence <joe.lawrence@stratus.com> - 2015-12-24 15:40 +0100
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