Date: Thu, 17 Jun 2010 12:40:30 -0400 From: Randall Stewart <rrs@lakerest.net> To: "Jayachandran C." <c.jayachandran@gmail.com> Cc: freebsd-mips@freebsd.org Subject: Re: Merging 64 bit changes to -HEAD - part 2 Message-ID: <4B66E1A4-E2A5-471F-9FA4-38B506797272@lakerest.net> In-Reply-To: <AANLkTimkF47RlysFOrma0YhWNDw2w5Lcp9SB1bBoPuxW@mail.gmail.com> References: <AANLkTimmIBz1sfRx8I8E0OhNQz8wEtBihr1YZ26QfYL0@mail.gmail.com> <98F8CB29-62FE-41A6-8AE6-6F8AF086D29C@lakerest.net> <20100617.100235.195066307596264499.imp@bsdimp.com> <AANLkTimkF47RlysFOrma0YhWNDw2w5Lcp9SB1bBoPuxW@mail.gmail.com>
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On Jun 17, 2010, at 12:23 PM, Jayachandran C. wrote:
> On Thu, Jun 17, 2010 at 9:32 PM, M. Warner Losh <imp@bsdimp.com>
> wrote:
>> In message: <98F8CB29-62FE-41A6-8AE6-6F8AF086D29C@lakerest.net>
>> Randall Stewart <rrs@lakerest.net> writes:
>> : JC:
>> :
>> : I don't think renaming the PTE entries to PG_ is a good idea.
>> :
>> : Way back in 2007 this was one of the issues I hit.. the J code
>> : used PG_ and somewhere in the VM we used PG_ to indicate (Page).
>> :
>> : Thus we ended up with a PG_G defined in two places and we were
>> setting
>> : PG_G and it was Not the PTE PG_G.. but the one defined in the VM.
>>
>> This was a big frustration at the time... I'd somehow blocked it
>> from
>> my memory when Juli and I talked about this a while ago...
>>
>> : The folks in the VM world suggested we change this to PTE_xxx
>> which I
>> : did.
>>
>> Alan Cox, if memory serves.
>
> I had tested the changes (buildworld on 32 cpus) , so there is a
> chance that the problem no longer exists.
>
> There is one minor cleanup in the patch that can be done (ie unify the
> mips_pg and pmap_pte macros). But the renaming itself does not seem to
> buy us anything.
>
> I will wait for Juli's comments too, as she is the original author of
> the patch...
>
But JC:
I don't understand why you have this urge to move PTE_xxx -> PG_xxx
a) We had that and changed that
b) Alan (I think you are right here Warner it was Alan that made the
suggestion) suggested
the changes to PTE_xx
So what are your reasons for wanting to do this?
R
> JC.
>
>
>> Warner
>>
>> : R
>> : On Jun 17, 2010, at 11:38 AM, Jayachandran C. wrote:
>> :
>> : > On Tue, Jun 15, 2010 at 7:06 PM, Jayachandran C.
>> : > <c.jayachandran@gmail.com> wrote:
>> : >> I have volunteered to merge Juli's 64-bit work into HEAD, and
>> : >> hopefully get it to work on XLR too. The tree
>> : >> (http://svn.freebsd.org/base/user/jmallett/octeon) has quite a
>> bit of
>> : >> changes, so I would like to do this over multiple changesets and
>> : >> without breaking the current o32 code.
>> : >
>> : > Here's part 2, containing two patches:
>> : >
>> : > pmap-PTE-to-PG.patch :
>> : >
>> : > This is a renaming patch with minor cleanup, The PTE_* flags are
>> : > renamed to PG_ and related changes are made to other files. I
>> have
>> : > tried to make this patch limited to just the renaming and the
>> changes
>> : > related to it. I will make another patch for the rest of the
>> minor
>> : > changes in pmap.c.
>> : >
>> : > My comment on this patch: The name PG_C_CNC for value 3 in
>> pte.h may
>> : > be confusing, at least on XLR. We don't have cached non-
>> coherent mode,
>> : > the cached memory is coherent(except L1 I-cache), so I would
>> prefer
>> : > PG_CACHED and PG_UNCACHED names.
>> : >
>> : > pmap-lgmem-lock-remove.patch :
>> : >
>> : > Remove the lock in local_sysmaps, and sched_pin()/unpin() in the
>> : > PMAP_LMEM_ macros.
>> : >
>> : > The 64-bit support changes would be next - comments on the
>> patches
>> : > esp. the first one is welcome.
>> : >
>> : > Thanks,
>> : > JC.
>> : > <pmap-PTE-to-PG.patch><pmap-lgmem-lock-remove.patch>
>> :
>> : ------------------------------
>> : Randall Stewart
>> : 803-317-4952 (cell)
>> :
>> :
>>
>
>
>
> --
> C. Jayachandran c.jayachandran@gmail.com
>
------------------------------
Randall Stewart
803-317-4952 (cell)
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