Yep, got it. I may have been looking at the wrong invoke() before.

Polina

On Sun, Mar 22, 2009 at 7:35 PM, Polina Dudnik <[email protected]> wrote:

> I see. I will look at that because it's weird that when I boot the disk it
> complains about unhandled MMU.
>
>
> On Sun, Mar 22, 2009 at 7:21 PM, Ali Saidi <[email protected]> wrote:
>
>>
>>
>> It is changed when fault->invoke() is called. It then vectors to the
>> OS which handles the fault and then calls retry(?) which rexecutes the
>> instruction and away it goes.
>>
>> Ali
>>
>> On Mar 22, 2009, at 6:11 PM, Polina Dudnik wrote:
>>
>> > Ali,
>> >
>> > I traced the FastDataAccessMMUMiss and it seems that the fault
>> > triggers advancePC function, which calls predecode.reset() and
>> > that's about it. predecode.reset() doesn't seem to be doing anything
>> > either. Shouldn't the PC be changed to the start of the handling
>> > routine? Or am I missing something? Where is the
>> > FastDataAccessMMUMiss actually handled?
>> >
>> > Polina
>> >
>> > On Sun, Mar 22, 2009 at 5:39 PM, Ali Saidi <[email protected]> wrote:
>> > number of CPUs as I've defined them. If you wanted 8 contexts you
>> > would pass -n 8
>> >
>> > Ali
>> >
>> > On Mar 22, 2009, at 5:09 PM, Polina Dudnik wrote:
>> >
>> > > So, when I pass -n 2, shouldn't there be 8 thread contexts: 4 for
>> > > each processor? Or is -n 2 is the number of CPUs as you define them?
>> > >
>> > > On Sun, Mar 22, 2009 at 5:02 PM, Ali Saidi <[email protected]> wrote:
>> > > The latter. The OS/hypervisor may believe that there are multiple
>> > > threads on a CPU, but in reality there are actually multiple CPUs.
>> > All
>> > > the code I wrote for threads/cpus as far as the OS/hypervisor
>> > layer is
>> > > concerned assumed this (e.g. take the thread context ID % 4 to get
>> > the
>> > > CPU/thread id.
>> > >
>> > > Ali
>> > >
>> > > On Mar 22, 2009, at 2:47 PM, Polina Dudnik wrote:
>> > >
>> > > > So, you just don't allow multiple threads on a cpu or you
>> > attempt to
>> > > > flatten out multiple threads into multiple cpus?
>> > > >
>> > > > On Fri, Mar 20, 2009 at 5:31 PM, Steve Reinhardt
>> > <[email protected]>
>> > > > wrote:
>> > > > By default, we do not simulate multithreading.  The SimpleCPU
>> > models
>> > > > are single-threaded.  The O3 model does have SMT capability, but
>> > > it's
>> > > > not enabled by default, and I'm not sure it's ever been used in FS
>> > > > mode so there may well be bugs there.
>> > > >
>> > > > Steve
>> > > >
>> > > > 2009/3/20 Polina Dudnik <[email protected]>:
>> > > > > Ali,
>> > > > >
>> > > > > Just to be clear: do or you do not simulate multithreading?
>> > > > >
>> > > > > There are two options that I can imagine:
>> > > > >
>> > > > > 1. When I pass -n 2 there are two multithreaded processors, each
>> > > > of which
>> > > > > has four thread contexts. In that case, seeing the ipi for
>> > > > "cpu_id" 4 is
>> > > > > completely right, because the ipi's come in for the threads, and
>> > > > not cpu's.
>> > > > > So, the simulator should not be getting confused about the ipi
>> > for
>> > > > 4.
>> > > > >
>> > > > >
>> > > > > OR
>> > > > >
>> > > > > 2. You simulate each thread context as a processor. In that
>> > case,
>> > > > when I
>> > > > > pass -n 2, there really should be 8 processors. In that case,
>> > > > again ipi for
>> > > > > 4 is entirely right.
>> > > > >
>> > > > > Which one is it?
>> > > > >
>> > > > > Thanks,
>> > > > >
>> > > > > Polina
>> > > > >
>> > > > >
>> > > > >
>> > > > >
>> > > > >
>> > > > >
>> > > > >
>> > > > >
>> > > > >
>> > > > >
>> > > > >
>> > > > > On Fri, Mar 20, 2009 at 2:54 PM, Polina Dudnik <[email protected]
>> > >
>> > > > wrote:
>> > > > >>
>> > > > >> Regarding running one processor with two threads, now that I
>> > > > think about
>> > > > >> it, OpenSparc definitely assigns thread numbers and not
>> > processor
>> > > > numbers in
>> > > > >> hardware description file. Niagara does not have 32 processors,
>> > > > but can have
>> > > > >> 32 threads. So, by assigning thread numbers to be 0 and 4, it
>> > > > ensures that
>> > > > >> the threads are run on different processors. This is why the
>> > > > number is 4. It
>> > > > >> is the thread number.
>> > > > >>
>> > > > >> So I think those really are the cpu numbers as seen by the OS,
>> > > > and they
>> > > > >> have to be swizzled.
>> > > > >>
>> > > > >> Can you please tell me where you got the format for the ipi
>> > > > message. So,
>> > > > >> to be more clear in iob.cc:
>> > > > >>
>> > > > >>
>> > > > >>             data = pkt->get<uint64_t>();
>> > > > >>             type = (Type)bits(data,17,16);
>> > > > >>             cpu_id = bits(data, 12,8);
>> > > > >>             vector = bits(data,5,0);
>> > > > >>             generateIpi(type,cpu_id, vector);
>> > > > >>
>> > > > >>
>> > > > >> How do you know that cpu_id is at bits 5 through 0? I keep
>> > > > looking through
>> > > > >> OpenSparc documentation but can't find it.
>> > > > >>
>> > > > >>
>> > > > >> Thanks.
>> > > > >>
>> > > > >> Polina
>> > > > >>
>> > > > >>
>> > > > >> On Fri, Mar 20, 2009 at 1:26 PM, Polina Dudnik
>> > > > <[email protected]> wrote:
>> > > > >>>
>> > > > >>>
>> > > > >>> On Fri, Mar 20, 2009 at 1:11 PM, Ali Saidi <[email protected]>
>> > > > wrote:
>> > > > >>>>
>> > > > >>>> Yea, that makes sense. You should probably look at the TLBs
>> > > > (that is
>> > > > >>>> where a lot of the miscellaneous system registers live). The
>> > > > confusion
>> > > > >>>> probably comes from reading one of those and the ids not
>> > being
>> > > > >>>> swizzeled, or perhaps there is an interrupt message with a
>> > CPU
>> > > > id or
>> > > > >>>> something as well.
>> > > > >>>
>> > > > >>>
>> > > > >>> Right, that's what I was thinking. I will look at the TLB's
>> > and
>> > > > the
>> > > > >>> interrupt. Perhaps you can help me with a more specific
>> > > > question: when I
>> > > > >>> post an interrupt, I basically write a bit in the interrupt
>> > > > array. How does
>> > > > >>> the hypervisor find out about it? Who reads the interrupt
>> > array?
>> > > > >>>
>> > > > >>>>
>> > > > >>>>
>> > > > >>>> I guess your attempts at convincing the hypervisor that the
>> > > > next cpu
>> > > > >>>> was #1 failed?
>> > > > >>>
>> > > > >>> It is not even that. According to David Wood, it might not be
>> > > > the best
>> > > > >>> idea to change cpu numbers because there are a lot of things
>> > > > that determine
>> > > > >>> the cpu numbers. So, I think the reason that changing the
>> > > hardware
>> > > > >>> description files did not have any effect is because the
>> > > > description files
>> > > > >>> are fitted to the hypervisor and not the other way around. I
>> > am
>> > > > right now
>> > > > >>> trying to find where the hardware description binary is used
>> > if
>> > > > ever.
>> > > > >>>
>> > > > >>>
>> > > > >>>>
>> > > > >>>> What about calling the next CPU thread 1 (e.g. make a
>> > > > >>>> system with 2 threads and 1 core)?
>> > > > >>>
>> > > > >>> Yes, I remember I was supposed to do that. Sorry for the
>> > delay,
>> > > > I will
>> > > > >>> certainly try that. Currently I am trying to run 32 processors
>> > > > because at
>> > > > >>> least they are ordered and shouldn't require swizzling, so
>> > we'll
>> > > > see what
>> > > > >>> happens.
>> > > > >>>
>> > > > >>>
>> > > > >>>>
>> > > > >>>> Ali
>> > > > >>>>
>> > > > >>>>
>> > > > >>>>
>> > > > >>>> On Mar 20, 2009, at 12:52 PM, Polina Dudnik wrote:
>> > > > >>>>
>> > > > >>>> > Right, I wasn't going to modify the hypervisor. But
>> > swizzling
>> > > > the
>> > > > >>>> > numbers clearly affects the hypervisor because when
>> > > > hypervisor sends
>> > > > >>>> > messages, the processor number is swizzled from 4 to 1. So,
>> > > > >>>> > initially the hypervisor thinks that there are cpu #0 and
>> > #4,
>> > > > but
>> > > > >>>> > then it probably receives some messages or whatever, which
>> > > > have cpu
>> > > > >>>> > #1. So, I think the reason that the hypervisor reports that
>> > > > cpu1
>> > > > >>>> > failed to start is due to the confusion over the cpu
>> > numbers.
>> > > > Does
>> > > > >>>> > this make sense?
>> > > > >>>> >
>> > > > >>>> > So, if m5 shall use cou #0 and #1 internally, it should
>> > make
>> > > > sure
>> > > > >>>> > that all the external messages are suited for the binaries
>> > > form
>> > > > >>>> > OpenSparc.
>> > > > >>>> >
>> > > > >>>> > Polin
>> > > > >>>> >
>> > > > >>>> > On Fri, Mar 20, 2009 at 12:02 PM, Ali Saidi <[email protected]
>> > >
>> > > > wrote:
>> > > > >>>> > The changes should only affect the portions of the system
>> > > > that the
>> > > > >>>> > hypervisor is calling. There shouldn't be any changes
>> > > > required within
>> > > > >>>> > the hypervisor code.
>> > > > >>>> >
>> > > > >>>> > Ali
>> > > > >>>> >
>> > > > >>>> > On Mar 19, 2009, at 1:22 PM, Polina Dudnik wrote:
>> > > > >>>> >
>> > > > >>>> > > Hi,
>> > > > >>>> > >
>> > > > >>>> > > So, to make sparc_fs work Ali and later I swizzled the
>> > > > processor
>> > > > >>>> > > numbers from 4 to 1 because m5 expects 1 and gets 4. In
>> > > > order to
>> > > > >>>> > > make this hack work, we also need to swizzle the numbers
>> > > > back before
>> > > > >>>> > > calling the hypervisor. So, the processor numbers going
>> > > > into the
>> > > > >>>> > > hypervisor should be swizzled back. So, in effect there
>> > > > should be a
>> > > > >>>> > > map which enables translation both ways. Does anyone know
>> > > > where I
>> > > > >>>> > > can start looking for calls to the hypervisor? Thank you.
>> > > > >>>> > >
>> > > > >>>> > > Polina
>> > > > >>>> > >
>> > > > >>>> > >
>> > > > >>>> > > _______________________________________________
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>> > > > >>>> >
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>> > > > >
>> > > > >
>> > > > > _______________________________________________
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>> > > > _______________________________________________
>> > > > m5-dev mailing list
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>> > > > _______________________________________________
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>> > >
>> > > _______________________________________________
>> > > m5-dev mailing list
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>> > > _______________________________________________
>> > > m5-dev mailing list
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>> >
>> > _______________________________________________
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>> >
>> > _______________________________________________
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