2010-02-10 20:02:53

by Alexander Lam

[permalink] [raw]
Subject: mtrr cleanup not doing anything on 2.6.33-rc7

Hi all,

Please CC: me when replying.

My kernel config has the following:
CONFIG_MTRR=y
CONFIG_MTRR_SANITIZER=y
CONFIG_MTRR_SANITIZER_ENABLE_DEFAULT=1
CONFIG_MTRR_SANITIZER_SPARE_REG_NR_DEFAULT=1

With previous kernels, dmesg would show that the sanitizer was indeed
cleaning up the mtrrs [1]

but now, with 2.6.33-rc7 there is no indication that this is occuring,
and the intel i915 driver complains:
[ 0.613419] i915 0000:00:02.0: PCI INT A -> GSI 16 (level, low) -> IRQ 16
[ 0.614577] i915 0000:00:02.0: setting latency timer to 64
[ 0.625446] mtrr: no more MTRRs available
[ 0.625529] [drm] MTRR allocation failed. Graphics performance
may suffer.

What has changed and what do I need to do to make the mtrr sanitation
work again?

[1]: dmesg from previous kernels:
[ 0.000000] MTRR default type: uncachable
[ 0.000000] MTRR fixed ranges enabled:
[ 0.000000] 00000-9FFFF write-back
[ 0.000000] A0000-BFFFF uncachable
[ 0.000000] C0000-C7FFF write-protect
[ 0.000000] C8000-EFFFF uncachable
[ 0.000000] F0000-FFFFF write-protect
[ 0.000000] MTRR variable ranges enabled:
[ 0.000000] 0 base 0FFFE0000 mask 0FFFE0000 write-protect
[ 0.000000] 1 base 0FFFC0000 mask 0FFFE0000 uncachable
[ 0.000000] 2 base 000000000 mask 0E0000000 write-back
[ 0.000000] 3 base 020000000 mask 0E0000000 write-back
[ 0.000000] 4 base 03F800000 mask 0FF800000 uncachable
[ 0.000000] 5 base 03F600000 mask 0FFE00000 uncachable
[ 0.000000] 6 base 03F500000 mask 0FFF00000 uncachable
[ 0.000000] 7 base 000000000 mask 0FFFE0000 uncachable
[ 0.000000] x86 PAT enabled: cpu 0, old 0x7040600070406, new 0x7010600070106
[ 0.000000] original variable MTRRs
[ 0.000000] reg 0, base: 4194176KB, range: 128KB, type WP
[ 0.000000] reg 1, base: 4194048KB, range: 128KB, type UC
[ 0.000000] reg 2, base: 0GB, range: 512MB, type WB
[ 0.000000] reg 3, base: 512MB, range: 512MB, type WB
[ 0.000000] reg 4, base: 1016MB, range: 8MB, type UC
[ 0.000000] reg 5, base: 1014MB, range: 2MB, type UC
[ 0.000000] reg 6, base: 1013MB, range: 1MB, type UC
[ 0.000000] reg 7, base: 0GB, range: 128KB, type UC
[ 0.000000] WARNING: BIOS bug: VAR MTRR 7 contains strange UC entry
under 1M, check with your system vendor!
[ 0.000000] total RAM coverred: 1013M
[ 0.000000] Found optimal setting for mtrr clean up
[ 0.000000] gran_size: 64K chunk_size: 16M num_reg: 4
lose cover RAM: 0G
[ 0.000000] New variable MTRRs
[ 0.000000] reg 0, base: 0GB, range: 1GB, type WB
[ 0.000000] reg 1, base: 1013MB, range: 1MB, type UC
[ 0.000000] reg 2, base: 1014MB, range: 2MB, type UC
[ 0.000000] reg 3, base: 1016MB, range: 8MB, type UC
[ 0.000000] x86 PAT enabled: cpu 0, old 0x7040600070406, new 0x7010600070106


Thanks,
--
Alexander Lam


2010-02-11 01:49:12

by Alexander Lam

[permalink] [raw]
Subject: Re: mtrr cleanup not doing anything on 2.6.33-rc7

On Wed, Feb 10, 2010 at 3:02 PM, Alexander Lam <[email protected]> wrote:
>
> My kernel config has the following:
> CONFIG_MTRR=y
> CONFIG_MTRR_SANITIZER=y
> CONFIG_MTRR_SANITIZER_ENABLE_DEFAULT=1
> CONFIG_MTRR_SANITIZER_SPARE_REG_NR_DEFAULT=1
>
> With previous kernels, dmesg would show that the sanitizer was indeed
> cleaning up the mtrrs [1]
>
> but now, with 2.6.33-rc7 there is no indication that this is occuring,

For those who run across this later,

Found out that commit 508d85c2c6bc8cba53d2a54d9a306ad64a0a80bf,
x86: When cleaning MTRRs, do not fold WP into UC

causes mtrr cleanup not to run on my machine.

Probably not worth fixing because the i915 error message is harmless.

2010-02-11 10:09:45

by Carlos Mafra

[permalink] [raw]
Subject: Re: mtrr cleanup not doing anything on 2.6.33-rc7

[Add people in that commit to Cc: list, just in case]

On Mi 10.Feb'10 at 20:48:49 -0500, Alexander Lam wrote:
> On Wed, Feb 10, 2010 at 3:02 PM, Alexander Lam <[email protected]> wrote:
> >
> > My kernel config has the following:
> > CONFIG_MTRR=y
> > CONFIG_MTRR_SANITIZER=y
> > CONFIG_MTRR_SANITIZER_ENABLE_DEFAULT=1
> > CONFIG_MTRR_SANITIZER_SPARE_REG_NR_DEFAULT=1
> >
> > With previous kernels, dmesg would show that the sanitizer was indeed
> > cleaning up the mtrrs [1]
> >
> > but now, with 2.6.33-rc7 there is no indication that this is occuring,
>
> For those who run across this later,
>
> Found out that commit 508d85c2c6bc8cba53d2a54d9a306ad64a0a80bf,
> x86: When cleaning MTRRs, do not fold WP into UC
>
> causes mtrr cleanup not to run on my machine.
>
> Probably not worth fixing because the i915 error message is harmless.
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/

2010-02-11 14:57:32

by H. Peter Anvin

[permalink] [raw]
Subject: Re: mtrr cleanup not doing anything on 2.6.33-rc7

On 02/11/2010 02:10 AM, Carlos R. Mafra wrote:
> [Add people in that commit to Cc: list, just in case]
>
> On Mi 10.Feb'10 at 20:48:49 -0500, Alexander Lam wrote:
>> On Wed, Feb 10, 2010 at 3:02 PM, Alexander Lam <[email protected]> wrote:
>>>
>>> My kernel config has the following:
>>> CONFIG_MTRR=y
>>> CONFIG_MTRR_SANITIZER=y
>>> CONFIG_MTRR_SANITIZER_ENABLE_DEFAULT=1
>>> CONFIG_MTRR_SANITIZER_SPARE_REG_NR_DEFAULT=1
>>>
>>> With previous kernels, dmesg would show that the sanitizer was indeed
>>> cleaning up the mtrrs [1]
>>>
>>> but now, with 2.6.33-rc7 there is no indication that this is occuring,
>>
>> For those who run across this later,
>>
>> Found out that commit 508d85c2c6bc8cba53d2a54d9a306ad64a0a80bf,
>> x86: When cleaning MTRRs, do not fold WP into UC
>>
>> causes mtrr cleanup not to run on my machine.
>>
>> Probably not worth fixing because the i915 error message is harmless.
>> --

You're not stating what your MTRR setup looks like, and hence if there
is anything to clean up.

-hpa

--
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel. I don't speak on their behalf.

2010-02-11 17:14:52

by Carlos Mafra

[permalink] [raw]
Subject: Re: mtrr cleanup not doing anything on 2.6.33-rc7

On Do 11.Feb'10 at 6:56:59 -0800, H. Peter Anvin wrote:
> On 02/11/2010 02:10 AM, Carlos R. Mafra wrote:
> > [Add people in that commit to Cc: list, just in case]
> >
> > On Mi 10.Feb'10 at 20:48:49 -0500, Alexander Lam wrote:
> >> On Wed, Feb 10, 2010 at 3:02 PM, Alexander Lam <[email protected]> wrote:
> >>>
> >>> My kernel config has the following:
> >>> CONFIG_MTRR=y
> >>> CONFIG_MTRR_SANITIZER=y
> >>> CONFIG_MTRR_SANITIZER_ENABLE_DEFAULT=1
> >>> CONFIG_MTRR_SANITIZER_SPARE_REG_NR_DEFAULT=1
> >>>
> >>> With previous kernels, dmesg would show that the sanitizer was indeed
> >>> cleaning up the mtrrs [1]
> >>>
> >>> but now, with 2.6.33-rc7 there is no indication that this is occuring,
> >>
> >> For those who run across this later,
> >>
> >> Found out that commit 508d85c2c6bc8cba53d2a54d9a306ad64a0a80bf,
> >> x86: When cleaning MTRRs, do not fold WP into UC
> >>
> >> causes mtrr cleanup not to run on my machine.
> >>
> >> Probably not worth fixing because the i915 error message is harmless.
> >> --
>
> You're not stating what your MTRR setup looks like, and hence if there
> is anything to clean up.

I am not sure if I am being an intruder here, but I also should
have quoted Alexander's first email:

Hi all,

Please CC: me when replying.

My kernel config has the following:
CONFIG_MTRR=y
CONFIG_MTRR_SANITIZER=y
CONFIG_MTRR_SANITIZER_ENABLE_DEFAULT=1
CONFIG_MTRR_SANITIZER_SPARE_REG_NR_DEFAULT=1

With previous kernels, dmesg would show that the sanitizer was indeed
cleaning up the mtrrs [1]

but now, with 2.6.33-rc7 there is no indication that this is occuring,
and the intel i915 driver complains:
[ 0.613419] i915 0000:00:02.0: PCI INT A -> GSI 16 (level, low) -> IRQ 16
[ 0.614577] i915 0000:00:02.0: setting latency timer to 64
[ 0.625446] mtrr: no more MTRRs available
[ 0.625529] [drm] MTRR allocation failed. Graphics performance
may suffer.

What has changed and what do I need to do to make the mtrr sanitation
work again?

[1]: dmesg from previous kernels:
[ 0.000000] MTRR default type: uncachable
[ 0.000000] MTRR fixed ranges enabled:
[ 0.000000] 00000-9FFFF write-back
[ 0.000000] A0000-BFFFF uncachable
[ 0.000000] C0000-C7FFF write-protect
[ 0.000000] C8000-EFFFF uncachable
[ 0.000000] F0000-FFFFF write-protect
[ 0.000000] MTRR variable ranges enabled:
[ 0.000000] 0 base 0FFFE0000 mask 0FFFE0000 write-protect
[ 0.000000] 1 base 0FFFC0000 mask 0FFFE0000 uncachable
[ 0.000000] 2 base 000000000 mask 0E0000000 write-back
[ 0.000000] 3 base 020000000 mask 0E0000000 write-back
[ 0.000000] 4 base 03F800000 mask 0FF800000 uncachable
[ 0.000000] 5 base 03F600000 mask 0FFE00000 uncachable
[ 0.000000] 6 base 03F500000 mask 0FFF00000 uncachable
[ 0.000000] 7 base 000000000 mask 0FFFE0000 uncachable
[ 0.000000] x86 PAT enabled: cpu 0, old 0x7040600070406, new 0x7010600070106
[ 0.000000] original variable MTRRs
[ 0.000000] reg 0, base: 4194176KB, range: 128KB, type WP
[ 0.000000] reg 1, base: 4194048KB, range: 128KB, type UC
[ 0.000000] reg 2, base: 0GB, range: 512MB, type WB
[ 0.000000] reg 3, base: 512MB, range: 512MB, type WB
[ 0.000000] reg 4, base: 1016MB, range: 8MB, type UC
[ 0.000000] reg 5, base: 1014MB, range: 2MB, type UC
[ 0.000000] reg 6, base: 1013MB, range: 1MB, type UC
[ 0.000000] reg 7, base: 0GB, range: 128KB, type UC
[ 0.000000] WARNING: BIOS bug: VAR MTRR 7 contains strange UC entry
under 1M, check with your system vendor!
[ 0.000000] total RAM coverred: 1013M
[ 0.000000] Found optimal setting for mtrr clean up
[ 0.000000] gran_size: 64K chunk_size: 16M num_reg: 4
lose cover RAM: 0G
[ 0.000000] New variable MTRRs
[ 0.000000] reg 0, base: 0GB, range: 1GB, type WB
[ 0.000000] reg 1, base: 1013MB, range: 1MB, type UC
[ 0.000000] reg 2, base: 1014MB, range: 2MB, type UC
[ 0.000000] reg 3, base: 1016MB, range: 8MB, type UC
[ 0.000000] x86 PAT enabled: cpu 0, old 0x7040600070406, new 0x7010600070106


Thanks,
--
Alexander Lam