Yes, that is exactly the "eageronly" features - currently LWP and MPX.
On February 1, 2014 6:05:05 PM PST, Linus Torvalds <[email protected]> wrote: >On Sat, Feb 1, 2014 at 5:57 PM, H. Peter Anvin <[email protected]> wrote: >> >> Twiddling CR0.TS is pretty slow if we're not taking advantage of it. > >Immaterial. > >We *already* avoid twiddling TS if it's not needed. > >It is true that we used to twiddle it at every context switch (and >then twiddle it *again* if we decided that we'd want to pre-load the >FPU state anyway, and avoid the extra fault). > >But that was fixed, and if we switch from a task that had math state >to another task that has math state, we leave TS alone. > >But Suresh apparently hits on the real issue: > >> not all the state under xsave adhers to cr0.TS/DNA rules > >which if so is sad but yes, makes CR0.TS no longer sufficient. > > Linus -- Sent from my mobile phone. Please pardon brevity and lack of formatting. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
