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Groups > linux.kernel > #1314425
| From | Thomas Gleixner <tglx@linutronix.de> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [RFC V2 1/2] irq: Add a framework to measure interrupt timings |
| Date | 2016-01-21 20:00 +0100 |
| Message-ID | <qTsCD-Pl-23@gated-at.bofh.it> (permalink) |
| References | (2 earlier) <qT6iK-2se-3@gated-at.bofh.it> <qT759-2KF-25@gated-at.bofh.it> <qTkc1-3tc-1@gated-at.bofh.it> <qTnWi-5YM-25@gated-at.bofh.it> <qTofE-6n5-3@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Thu, 21 Jan 2016, Daniel Lezcano wrote: > On 01/21/2016 02:52 PM, Thomas Gleixner wrote: > > And why would that thing care about shared interruts at all? It's a legacy > > burden and I really don't see a reason why that new thing which is > > targeted on modern hardware should deal with them. Just treat them as a > > single interrupt for now and be done with it. > > If the shared interrupts are only related to old hardware, these ones > shouldn't have cpuidle, hence there is no need to enable the irq timings. So > you are right in this case and we can keep the feature simple. > > On a other hand, Peter sent three examples of /proc/interrupts with shared > interrupts. I don't know how old are the platforms and what are they, but it > seems the shared irq are still used. Well, its still there on x86 but slowly on the way out. What I meant with legacy burden is, that the HW people finally got the idea that shared interrupts are a horrible concept. So we are seing them go away. My laptop (not the newest thingy) doesn't have them anymore. Most devices use MSI now, except for the holdouts: 0: 20 0 0 0 IO-APIC-edge timer 1: 1 1 5 3 IO-APIC-edge i8042 8: 5 6 0 4 IO-APIC-edge rtc0 9: 294 1231 118 318 IO-APIC-fasteoi acpi 12: 96 1748 55 76 IO-APIC-edge i8042 18: 0 0 0 0 IO-APIC 18-fasteoi i801_smbus 23: 11 12 8 51 IO-APIC 23-fasteoi ehci_hcd:usb1 My latest server toy still has one shared entry: 18-fasteoi ehci_hcd:usb1, ehci_hcd:usb2, i801_smbus which is just a complete braindamage on the hardware side. There are a gazillion of free interrupt lines on that beast and of course they must route 3 devices to the same line. We really should ignore that sillyness and if people complain, make them complain to their HW vendor. That's the only way this crap will go away. If we just keep on supporting this completely pointless nonsense the HW folks will just not fix it. We've been successful in the past to 'educate' hw people by making features not available for mindless designs. In this case we still support the feature, but it might be suboptimal. The real interesting ports on that platform are MSI anyway, so I really couldn't care less. I have no idea how wide spread the shared nonsense is on the relevant ARM platforms, but you might be able to figure that out faster than me. Thanks, tglx
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Re: [RFC PATCH 2/2] sched: idle: IRQ based next prediction for idle period Daniel Lezcano <daniel.lezcano@linaro.org> - 2016-01-18 14:30 +0100
Re: [RFC PATCH 2/2] sched: idle: IRQ based next prediction for idle period Thomas Gleixner <tglx@linutronix.de> - 2016-01-20 16:50 +0100
[RFC V2 2/2] sched: idle: IRQ based next prediction for idle period Daniel Lezcano <daniel.lezcano@linaro.org> - 2016-01-20 17:10 +0100
Re: [RFC V2 2/2] sched: idle: IRQ based next prediction for idle period Nicolas Pitre <nicolas.pitre@linaro.org> - 2016-01-20 18:50 +0100
Re: [RFC V2 2/2] sched: idle: IRQ based next prediction for idle period Peter Zijlstra <peterz@infradead.org> - 2016-01-20 19:50 +0100
Re: [RFC V2 2/2] sched: idle: IRQ based next prediction for idle period Daniel Lezcano <daniel.lezcano@linaro.org> - 2016-01-21 11:10 +0100
Re: [RFC V2 2/2] sched: idle: IRQ based next prediction for idle period Peter Zijlstra <peterz@infradead.org> - 2016-01-20 20:10 +0100
Re: [RFC V2 2/2] sched: idle: IRQ based next prediction for idle period Nicolas Pitre <nicolas.pitre@linaro.org> - 2016-01-20 20:20 +0100
Re: [RFC V2 2/2] sched: idle: IRQ based next prediction for idle period Peter Zijlstra <peterz@infradead.org> - 2016-01-20 20:40 +0100
Re: [RFC V2 2/2] sched: idle: IRQ based next prediction for idle period Peter Zijlstra <peterz@infradead.org> - 2016-01-20 20:40 +0100
Re: [RFC V2 2/2] sched: idle: IRQ based next prediction for idle period Peter Zijlstra <peterz@infradead.org> - 2016-01-20 20:50 +0100
Re: [RFC V2 2/2] sched: idle: IRQ based next prediction for idle period Nicolas Pitre <nicolas.pitre@linaro.org> - 2016-01-20 21:00 +0100
Re: [RFC V2 2/2] sched: idle: IRQ based next prediction for idle period Peter Zijlstra <peterz@infradead.org> - 2016-01-20 21:30 +0100
Re: [RFC V2 2/2] sched: idle: IRQ based next prediction for idle period Thomas Gleixner <tglx@linutronix.de> - 2016-01-20 21:00 +0100
Re: [RFC V2 2/2] sched: idle: IRQ based next prediction for idle period Daniel Lezcano <daniel.lezcano@linaro.org> - 2016-01-21 15:00 +0100
Re: [RFC V2 2/2] sched: idle: IRQ based next prediction for idle period Thomas Gleixner <tglx@linutronix.de> - 2016-01-21 15:20 +0100
[RFC V2 0/2] IRQ based next prediction Daniel Lezcano <daniel.lezcano@linaro.org> - 2016-01-20 17:10 +0100
[RFC V2 2/2] sched: idle: IRQ based next prediction for idle period Daniel Lezcano <daniel.lezcano@linaro.org> - 2016-01-20 17:10 +0100
Re: [RFC V2 2/2] sched: idle: IRQ based next prediction for idle period Nicolas Pitre <nicolas.pitre@linaro.org> - 2016-01-20 21:20 +0100
Re: [RFC V2 2/2] sched: idle: IRQ based next prediction for idle period Daniel Lezcano <daniel.lezcano@linaro.org> - 2016-01-21 14:10 +0100
[RFC V2 0/2] IRQ based next prediction Daniel Lezcano <daniel.lezcano@linaro.org> - 2016-01-20 17:10 +0100
[RFC V2 1/2] irq: Add a framework to measure interrupt timings Daniel Lezcano <daniel.lezcano@linaro.org> - 2016-01-20 17:10 +0100
Re: [RFC V2 1/2] irq: Add a framework to measure interrupt timings Thomas Gleixner <tglx@linutronix.de> - 2016-01-20 19:00 +0100
Re: [RFC V2 1/2] irq: Add a framework to measure interrupt timings Daniel Lezcano <daniel.lezcano@linaro.org> - 2016-01-21 10:30 +0100
Re: [RFC V2 1/2] irq: Add a framework to measure interrupt timings Thomas Gleixner <tglx@linutronix.de> - 2016-01-21 11:30 +0100
Re: [RFC V2 1/2] irq: Add a framework to measure interrupt timings Peter Zijlstra <peterz@infradead.org> - 2016-01-20 20:10 +0100
Re: [RFC V2 1/2] irq: Add a framework to measure interrupt timings Thomas Gleixner <tglx@linutronix.de> - 2016-01-20 21:00 +0100
Re: [RFC V2 1/2] irq: Add a framework to measure interrupt timings Nicolas Pitre <nicolas.pitre@linaro.org> - 2016-01-20 21:10 +0100
Re: [RFC V2 1/2] irq: Add a framework to measure interrupt timings Peter Zijlstra <peterz@infradead.org> - 2016-01-20 21:30 +0100
Re: [RFC V2 1/2] irq: Add a framework to measure interrupt timings Thomas Gleixner <tglx@linutronix.de> - 2016-01-20 21:30 +0100
Re: [RFC V2 1/2] irq: Add a framework to measure interrupt timings Daniel Lezcano <daniel.lezcano@linaro.org> - 2016-01-21 11:00 +0100
Re: [RFC V2 1/2] irq: Add a framework to measure interrupt timings Peter Zijlstra <peterz@infradead.org> - 2016-01-21 11:10 +0100
Re: [RFC V2 1/2] irq: Add a framework to measure interrupt timings Daniel Lezcano <daniel.lezcano@linaro.org> - 2016-01-21 13:40 +0100
Re: [RFC V2 1/2] irq: Add a framework to measure interrupt timings Thomas Gleixner <tglx@linutronix.de> - 2016-01-21 21:30 +0100
Re: [RFC V2 1/2] irq: Add a framework to measure interrupt timings Thomas Gleixner <tglx@linutronix.de> - 2016-01-21 15:00 +0100
Re: [RFC V2 1/2] irq: Add a framework to measure interrupt timings Daniel Lezcano <daniel.lezcano@linaro.org> - 2016-01-21 15:20 +0100
Re: [RFC V2 1/2] irq: Add a framework to measure interrupt timings Thomas Gleixner <tglx@linutronix.de> - 2016-01-21 20:00 +0100
Re: [RFC V2 1/2] irq: Add a framework to measure interrupt timings Peter Zijlstra <peterz@infradead.org> - 2016-01-22 11:20 +0100
Re: [RFC V2 1/2] irq: Add a framework to measure interrupt timings Daniel Lezcano <daniel.lezcano@linaro.org> - 2016-01-21 10:30 +0100
Re: [RFC V2 1/2] irq: Add a framework to measure interrupt timings Peter Zijlstra <peterz@infradead.org> - 2016-01-20 20:30 +0100
Re: [RFC V2 1/2] irq: Add a framework to measure interrupt timings Daniel Lezcano <daniel.lezcano@linaro.org> - 2016-01-21 11:00 +0100
[RFC V2 1/2] irq: Add a framework to measure interrupt timings Daniel Lezcano <daniel.lezcano@linaro.org> - 2016-01-20 17:10 +0100
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