Messages in this thread | | | From | Thomas Gleixner <> | Subject | Re: [RFC 2/2] timers: Make sure irq_work is handled when no pending timers | Date | Sat, 19 Jun 2021 10:22:43 +0200 |
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On Sat, Jun 19 2021 at 00:47, Thomas Gleixner wrote: > On Thu, Jun 10 2021 at 14:59, Nicolas Saenz Julienne wrote: > As we since then made work queues RT aware and it's possible to queue > work from the irq_work IPI context, the obvious solution is to delegate > this to a work queue. > > If we do a proper analysis of the affected irq work callbacks then this > probably makes a lot of sense independent of RT. There are only a few > really urgent irq work items which need to be handled immediately in the > IPI. > > RT is special, but as we have demonstrated over time it's not _that_ > special. It just needs a proper analysis and a real good argument why > something has to be special for RT and does not fit into the common > case. Or to demonstrate that the common case approach of 'do it right > away' is pointless or even harmfull.
I skimmed most of the ~40 irq_work instances.
Most of them have no urgency at all. And out of those non-urgent cases the majority does not even have the requirement to run on the current CPU, so they can be pushed off to a global work queue which moves them away from NOHZ full CPUs completely.
That has nothing to do with RT, that's a benefit in general.
Thanks,
tglx
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