Messages in this thread | | | Date | Wed, 7 May 2014 13:14:22 +0200 | From | Ingo Molnar <> | Subject | Re: [ABOMINATION] x86: Fast interrupt return to userspace |
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* Andy Lutomirski <luto@amacapital.net> wrote:
> > Whatever. I got enough profile data to say that it seems to have > > cut 'iret' overhead by at least two thirds. So it may not *work*, > > but from a "hey look, some random numbers" standpoint it is worth > > playing with. > > :) > > Is there actual interest in turning something like this into a real > patch? It would almost certainly have to default off and no one > sane would ever use it except for special-purpose machines.
The macro speedup looks rather impressive, and we've done ugly things for far smaller speedups.
But I don't think it should be a 'special mode'. It either is made to work unconditionally and can be a prime speedup to be proud of in a politely disgusted fashion, or we don't want the complexity (and future bitrot) of some special switch.
At minimum it can be a "look we want this speedup in hardware" testcase to CPU designers.
Thanks,
Ingo
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