Messages in this thread | | | Date | Fri, 11 Oct 2002 00:52:21 +0200 | From | Martin Waitz <> | Subject | weird semantics of cpu/*/msr |
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hi :)
the i386 msr driver is a bit strange:
* when reading/writing, it does not update the file position/msr register * file position is used directly as msr register
that is, reads with count>8 do read from the same register multiple times, and writes overwrite themselves.
i would expect the following semantics: * file position is (msr register * 8). position%8!=0 is invalid * read/write updating file position.
that would make it possible to write/read multiple MSRs with one syscall, which is very handy when initializing P4 performance counters.
should i implement that behaviour? of course it would break binary compatibility with existing uses of that drivers. perhaps we would need a new location for the new api.
comments?
-- CU, / Friedrich-Alexander University Erlangen, Germany Martin Waitz // [Tali on IRCnet] [tali.home.pages.de] _________ ______________/// - - - - - - - - - - - - - - - - - - - - /// dies ist eine manuell generierte mail, sie beinhaltet // tippfehler und ist auch ohne grossbuchstaben gueltig. / - Wer bereit ist, grundlegende Freiheiten aufzugeben, um sich kurzfristige Sicherheit zu verschaffen, der hat weder Freiheit noch Sicherheit verdient. Benjamin Franklin (1706 - 1790) [unhandled content-type:application/pgp-signature] | |