Messages in this thread | | | Date | Fri, 21 Jul 2017 03:55:26 +0100 (WEST) | Subject | Re: [PATCH 0/2] sparc64: Use low latency path to resume idle cpu | From | David Miller <> |
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From: Vijay Kumar <vijay.ac.kumar@oracle.com> Date: Thu, 20 Jul 2017 21:44:24 -0500
> I had same thoughts initially but I had to go with this approach as > scheduler_ipi is wrapped with irq_enter() and irq_exit(). Whereas POKE > resumes the cpu in process context. > > Comments in scheduler_ipi(): > > * Not all reschedule IPI handlers call irq_enter/irq_exit, since > * traditionally all their work was done from the interrupt return > * path. Now that we actually do some work, we need to make sure > * we do call them. > * > * Some archs already do call them, luckily irq_enter/exit nest > * properly. > * > * Arguably we should visit all archs and update all handlers, > * however a fair share of IPIs are still resched only so this would > * somewhat pessimize the simple resched case. > */ > irq_enter(); >
I still think we should be able to fake the state such that this direct schedule_ipi() call will work.
I could be wrong :)
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