Re: Difference between capability and memory mapping
Yuxin Ren <[email protected]>
| Newsgroups | gmane.comp.micro-kernel.l4.devel |
|---|---|
| Message-ID | <CAAKbDrctvyP38imeb-SD2o6n+rLuFM54DKJMuNRQa_f0Es4CWA@mail.gmail.com> |
On my machine, cap mapping is faster than memory. I do not think there is tlb flush in memory mapping. It only happens when memory is unmapped, right? But I found the mapping database for them are very different. Cap mapping database is simpler than the memory's. Thank you very much. Yuxin On Tue, Sep 30, 2014 at 5:15 PM, Adam Lackorzynski < [email protected]> wrote: > Hi, > > On Mon Sep 29, 2014 at 13:24:56 -0400, Yuxin Ren wrote: > > I found in the kernel, the capability mapping and memory mapping have > very > > similar code path. > > But I found their performance difference is around 1000 cycles. > > Is this true? If it is true, why do they have such large difference? > > If this gap does not make sense, it should be a bug in my test. > > Hmm, yes, there can be a difference. Of course, the number depends on > the hardware. Which one was slower/faster? For example, for memory there > there could be the need to TLB flushes, so it could be slower than cap > mappings. > > > > Adam > -- > Adam [email protected] > Lackorzynski http://os.inf.tu-dresden.de/~adam/ > > _______________________________________________ > l4-hackers mailing list > [email protected] > http://os.inf.tu-dresden.de/mailman/listinfo/l4-hackers > _______________________________________________ l4-hackers mailing list [email protected] http://os.inf.tu-dresden.de/mailman/listinfo/l4-hackers