From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Zijlstra Subject: Re: [RFC V2 1/2] irq: Add a framework to measure interrupt timings Date: Thu, 21 Jan 2016 11:08:34 +0100 Message-ID: <20160121100834.GM6356@twins.programming.kicks-ass.net> References: <1453305636-22156-1-git-send-email-daniel.lezcano@linaro.org> <1453305636-22156-2-git-send-email-daniel.lezcano@linaro.org> <20160120190718.GS6357@twins.programming.kicks-ass.net> <56A0A9E3.2070306@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from bombadil.infradead.org ([198.137.202.9]:50383 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756718AbcAUKIi (ORCPT ); Thu, 21 Jan 2016 05:08:38 -0500 Content-Disposition: inline In-Reply-To: <56A0A9E3.2070306@linaro.org> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Daniel Lezcano Cc: Thomas Gleixner , rafael@kernel.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, nicolas.pitre@linaro.org, vincent.guittot@linaro.org On Thu, Jan 21, 2016 at 10:50:27AM +0100, Daniel Lezcano wrote: > Actually, the handle passes dev_id in order to let the irqtimings to sort > out a shared interrupt and prevent double sampling. In other words, for > shared interrupts, statistics should be per t-uple(irq , dev_id) but that is > something I did not implemented ATM. > > IMO, the handler is at the right place. The prediction code does not take > care of the shared interrupts yet. That certainly added to the confusion. But if you want per dev_id stats, the whole alloc framework is 'broken' too, for it allocates the stuff per irq. > I tried to find a platform with shared interrupts in the ones I have > available around me but I did not find any. Are the shared interrupts > something used nowadays or coming from legacy hardware ? What is the > priority to handle the shared interrupts in the prediction code ? They're less common (thankfully) than they used to be, but I still have them: root@ivb-ep:~# cat /proc/interrupts | grep "," 59: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 IO-APIC 5-fasteoi i801_smbus, i801_smbus root@wsm-ep:~# cat /proc/interrupts | grep "," 18: 0 0 0 0 0 0 0 0 0 0 0 0 IO-APIC 18-fasteoi ehci_hcd:usb1, uhci_hcd:usb6 19: 9695230 19577242 13205011 3970578 740376 1138693 0 0 0 0 0 0 IO-APIC 19-fasteoi uhci_hcd:usb5, ata_piix 23: 3 0 0 0 927 0 0 0 0 0 0 0 IO-APIC 23-fasteoi ehci_hcd:usb2, uhci_hcd:usb4 root@snb:~# cat /proc/interrupts | grep "," 19: 11058485 0 0 0 0 0 0 0 IO-APIC 19-fasteoi ata_piix, ata_piix Also there's a whole host of SOCs that has them.