Messages in this thread | | | Subject | Re: [RFC GIT PULL] softirq: Consolidation and stack overrun fix | From | Benjamin Herrenschmidt <> | Date | Tue, 24 Sep 2013 19:31:39 +1000 |
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On Tue, 2013-09-24 at 10:21 +0200, Peter Zijlstra wrote: > > I don't see how that relates to the above though... > > It was a comment on the increase of per-cpu usage in generic code.
Oh I see. Ok, but some things are intrinsically per-task so if you use per-cpu in that case you end up context switching, at least that's what Linus alluded to. It would be nice if such construct we design so that we still access them via the task struct on arch where such accesses are cheap.
I think if/when we get rid of using r13 for our arch specific "PACA", it becomes easy for me to experiment with using it for either per-cpu or current and do some measurements. It also means I can easily switch "the other way" if I need to. I'll dig into that, it will probably take some time before I sanitize our code enough anyway.
Cheers, Ben.
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