On Mon, May 4, 2015 at 6:10 PM, Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote: > On Mon, 4 May 2015, Amir Vadai wrote: > >> On Mon, May 4, 2015 at 6:15 AM, Jiang Liu <jiang.liu@xxxxxxxxxxxxxxx> wrote: >> > The field 'affinity' in irq_desc won't change once the irq_desc data >> > structure is created. So cache irq_desc->affinity instead of irq_desc. >> > This also helps to hide struct irq_desc from device drivers. >> >> Hi Jiang, >> >> I might not understand the new changes irq core, but up until now >> affinity was changed when the user changed it through >> /proc/irq/<IRQ>/smp_affinity. >> This code is monitoring the affinity from the napi_poll context to >> detect affinity changes, and prevent napi from keep running on the >> wrong CPU. >> Therefore, the affinity can't be cached at the beginning. Please >> revert this caching. > > Sigh. All of this is completely wrong. Polling in the internals of > irq_desc is just crap. Hi, > > irq_set_affinity_notifier() has been added for exactly this purpose. rmap is already registered on irq_set_affinity_notifier(). Actually, I did post an extension to the affinity notifier, to use affinity chain which you rejected [1] (and BTW, convinced me that this is not the way to do it). Current code is according to your suggestion. [1] - https://lkml.org/lkml/2014/5/26/222 Amir > > Please get rid of your irq_desc abuse. > > Thanks, > > tglx > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
