On Sun, 2013-01-13 at 21:36 +0200, Alexander Motin wrote: > On 13.01.2013 20:09, Marius Strobl wrote: [...] > > > > Uhm, there are no NMIs on sparc64. Does it make sense to bypass this > > adjustment on sparc64? > > If it is not possible or not good to to stop timer during programming, > there will always be some race window between code execution and timer > ticking. So some minimal safety range should be reserved. Though it > probably can be significantly reduced. In case of x86/HPET there is > additional factor of NMI, that extends race to unpredictable level and > so makes additional post-read almost mandatory. > > >> May be with rereading counter > >> after programming comparator (same as done for HPET, reading which is > >> probably much more expensive) this value could be reduced. > > > > I see. There are some bigger fish to fry at the moment though :) >
Speaking of the HPET code, it seems to me that its restart logic can fire the same event twice. Is that harmless? -- Ian _______________________________________________ freebsd-current@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"
