The requests are queued in the core for the FPU access. Each execution engine has a pipeline to the FPU on the UltraSPARC-T2 and UltraSPARC-T2+. So it's more dependent on which thread is active on the execution engine that requests for a FP operation. I'm not sure if the thread is context switched out of the execution engine while the FPU is processing or not. I'd have to look at the specs again and see how that operation works. I know the details are on the opensparc.net website.
*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-* Octave J. Orgeron Solaris Systems Engineer http://www.opensolaris.org/os/community/sysadmin/ http://unixconsole.blogspot.com unixconsole at yahoo.com *-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-* ----- Original Message ---- From: Maciej Browarski <[email protected]> To: Octave Orgeron <unixconsole at yahoo.com> Cc: ldoms-discuss at opensolaris.org Sent: Tuesday, June 24, 2008 6:37:08 AM Subject: Re: [ldoms-discuss] guest domain and FPU So, all FP instruction are queued from all virtual processors or dropped ? In theoretical situation, when all 8 virtual processor what to make fsquare, what happen (In know that FP instruction need more than one clock cycles) ? Regards Maciej Octave Orgeron wrote: > The FPU is separate from the crypto. It's shared in the core, so all the > execution engines have access to it. > > *-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-* > Octave J. Orgeron > Solaris Systems Engineer > http://www.opensolaris.org/os/community/sysadmin/ > http://unixconsole.blogspot.com > unixconsole at yahoo.com > *-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-* > > > ----- Original Message ---- > From: Maciej Browarski <Maciej.Browarski at Sun.COM> > To: ldoms-discuss at opensolaris.org > Sent: Tuesday, June 24, 2008 4:03:21 AM > Subject: [ldoms-discuss] guest domain and FPU > > Hello, > What mean 1 FPU per core ? > If I divide 1 core to 2 guest domain I also divide FPU (timeshared or > else ?) or FPU goes with MAU ? > If FPU goes with MAU how floating point instruction are executed ? > > Regards, > >
