Messages in this thread | | | Date | Fri, 20 Feb 2015 09:32:39 -0800 | From | Arjan van de Ven <> | Subject | Re: [PATCH tip/core/rcu 0/4] Programmatic nestable expedited grace periods |
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>>>> Does it really make a machine boot much faster? Why are people using >>>> synchronous gp primitives if they care about speed? Should we not fix >>>> that instead? >>> >>> The report I heard was that it provided 10-15% faster boot times. >> >> That's not insignificant; got more details? I think we should really >> look at why people are using the sync primitives. > > I must defer to the people who took the exact measurements. > > But yes, once I have that info, I should add it to the commit log.
so the two most obvious cases are
Registering sysrq keys ... even when the old key code had no handler (have a patch pending for this)
registering idle handlers (this is more tricky, it's very obvious abuse but the fix is less clear)
there's a few others as well that I'm chasing down... .. but the flip side, prior to running ring 3 code, why NOT do fast expedites?
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