From mboxrd@z Thu Jan 1 00:00:00 1970 From: sudeep.holla@arm.com (Sudeep Holla) Date: Thu, 28 Aug 2014 11:12:15 +0100 Subject: [PATCH] arm: use cpu_online_mask when using forced irq_set_affinity In-Reply-To: References: <1399653640-21559-1-git-send-email-sudeep.holla@arm.com> <20140523121032.GV3693@n2100.arm.linux.org.uk> <537F4453.5000709@arm.com> <53A43174.503@arm.com> <20140620151638.GS32514@n2100.arm.linux.org.uk> <53C79E43.6040009@arm.com> <53FCA570.1090809@arm.com> Message-ID: <53FF007F.6030004@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 28/08/14 10:32, Thomas Gleixner wrote: > On Tue, 26 Aug 2014, Sudeep Holla wrote: >>>> Can provide your thoughts on how to solve this issue ? >>> >>> ffde1de64012 is not about offlining a cpu, it's about onlining where >>> we need to make sure that we assign the affinity to a not yet online >>> marked cpu. >>> >>>> Is it expected from all the irqchip implementation to use force flag in >>>> irq_set_affinity to ignore cpu_online_mask similar to GIC ? >>> >>> No, it's only relevant for the cases where we need to route irqs to >>> not yet online cpus. >>> >> >> Ok. IIUC Russell's main concern was if irqchip implementation uses force >> flag differently, then we can't change the core code to false. Also >> x86 core code also uses forced irq_set_affinity in arch/x86/kernel/irq.c > > Which is pointless as none of the x86 irq chip implementations > actually honours the force argument. > > In fact until the point where I implemented it in the GIC driver, > nothing ever used that argument. So the GIC conversion actually added > semantics to the argument. Any driver which will make use of it, has > to follow that now. I'll add documentation to the core code for it ... > Thanks Thomas for confirming. Hi Russell, Can I post the patch changing force to false in irq_set_affinity call to fix the issue and cc stable ? It's broken in stable kernels(v3.10 and v3.14) Regards, Sudeep