* [gentoo-user] IOMMU and other oddities...
@ 2011-08-09 5:32 meino.cramer
2011-08-09 5:58 ` Adam Carter
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: meino.cramer @ 2011-08-09 5:32 UTC (permalink / raw
To: Gentoo
[-- Attachment #1: Type: text/plain, Size: 1141 bytes --]
Hi,
my PC consists -- beside other things -- of a AMD Phenom II X6 1090T,
a ASUS Crossfire Formula IV and a NVidia GeForce GT 430 by MSI (PCIe).
Furthermore I am using the vanilla Linux kernel 3.0.1. .
I browsed through the output of dmesg and found these lines:
Checking aperture...
No AGP bridge found
Node 0: aperture @ c4000000 size 32 MB
Aperture pointing to e820 RAM. Ignoring.
Your BIOS doesn't leave a aperture memory hole
Please enable the IOMMU option in the BIOS setup
This costs you 64 MB of RAM
Mapping aperture over 65536 KB of RAM @ c4000000
The kernel is not configured with any AGP-related (as far as I now)
feature/config.
Why does it look for an AGP-bridge???
The dmesg says I should switch on IOMMU, which I did. But that does
not impress the kernel that much since it still recommends to switch
on IOMMU.
What did I wrong here ?
I want to fix issues, which may be reported by dmesg, so:
Where can I find explanations to the dmesg output?
For your information I attached the compressed dmesg output
to this mail.
Thank you very much for your help in advance!
Best regards
mcc
[-- Attachment #2: dmesg-out.txt.7z --]
[-- Type: application/octet-stream, Size: 10556 bytes --]
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [gentoo-user] IOMMU and other oddities...
2011-08-09 5:32 [gentoo-user] IOMMU and other oddities meino.cramer
@ 2011-08-09 5:58 ` Adam Carter
2011-08-09 6:31 ` meino.cramer
2011-08-09 8:58 ` pk
2011-08-10 15:56 ` Volker Armin Hemmann
2 siblings, 1 reply; 6+ messages in thread
From: Adam Carter @ 2011-08-09 5:58 UTC (permalink / raw
To: gentoo-user
> The dmesg says I should switch on IOMMU, which I did. But that does
> not impress the kernel that much since it still recommends to switch
> on IOMMU.
Did you remember to copy the new kernel over to boot etc :)
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [gentoo-user] IOMMU and other oddities...
2011-08-09 5:58 ` Adam Carter
@ 2011-08-09 6:31 ` meino.cramer
0 siblings, 0 replies; 6+ messages in thread
From: meino.cramer @ 2011-08-09 6:31 UTC (permalink / raw
To: gentoo-user
Adam Carter <adamcarter3@gmail.com> [11-08-09 08:04]:
> > The dmesg says I should switch on IOMMU, which I did. But that does
> > not impress the kernel that much since it still recommends to switch
> > on IOMMU.
>
> Did you remember to copy the new kernel over to boot etc :)
>
Yepp!
(...and I not only remember it...I did it ;) )
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [gentoo-user] IOMMU and other oddities...
2011-08-09 5:32 [gentoo-user] IOMMU and other oddities meino.cramer
2011-08-09 5:58 ` Adam Carter
@ 2011-08-09 8:58 ` pk
2011-08-09 11:22 ` meino.cramer
2011-08-10 15:56 ` Volker Armin Hemmann
2 siblings, 1 reply; 6+ messages in thread
From: pk @ 2011-08-09 8:58 UTC (permalink / raw
To: gentoo-user
On 2011-08-09 07:32, meino.cramer@gmx.de wrote:
> Why does it look for an AGP-bridge???
Not that it helps but, I also have an AMD system (AM3+, FX990/SB950) and
I get the "No AGP bridge found" message too...
> The dmesg says I should switch on IOMMU, which I did. But that does
> not impress the kernel that much since it still recommends to switch
> on IOMMU.
>
> What did I wrong here ?
I can make the IOMMU message disappear in my system with a "bios" setting...
Two things that I can think of:
1. Check your bios to make sure it does enable the IOMMU (i.e. was the
setting saved?).
2. Update your bios to see if it helps (but make sure you follow any
instructions from the m/b manufacturer).
> I want to fix issues, which may be reported by dmesg, so:
> Where can I find explanations to the dmesg output?
Don't know if there is such a place to "decode" the dmesg output but if
you wish to know more about these particular messages (well the
"terminology" and the technical explanation):
https://secure.wikimedia.org/wikipedia/en/wiki/Iommu
https://secure.wikimedia.org/wikipedia/en/wiki/Aperture_%28computer_memory%29
Some more digging (but I'm not sure it would help you)...
http://bogdan.org.ua/2009/09/30/iommu-this-costs-you-64-mb-of-ram.html
Best regards / MfG
Peter K
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [gentoo-user] IOMMU and other oddities...
2011-08-09 8:58 ` pk
@ 2011-08-09 11:22 ` meino.cramer
0 siblings, 0 replies; 6+ messages in thread
From: meino.cramer @ 2011-08-09 11:22 UTC (permalink / raw
To: gentoo-user
pk <peterk2@coolmail.se> [11-08-09 13:11]:
> On 2011-08-09 07:32, meino.cramer@gmx.de wrote:
>
> > Why does it look for an AGP-bridge???
>
> Not that it helps but, I also have an AMD system (AM3+, FX990/SB950) and
> I get the "No AGP bridge found" message too...
>
> > The dmesg says I should switch on IOMMU, which I did. But that does
> > not impress the kernel that much since it still recommends to switch
> > on IOMMU.
> >
> > What did I wrong here ?
>
> I can make the IOMMU message disappear in my system with a "bios" setting...
>
> Two things that I can think of:
> 1. Check your bios to make sure it does enable the IOMMU (i.e. was the
> setting saved?).
> 2. Update your bios to see if it helps (but make sure you follow any
> instructions from the m/b manufacturer).
>
> > I want to fix issues, which may be reported by dmesg, so:
> > Where can I find explanations to the dmesg output?
>
> Don't know if there is such a place to "decode" the dmesg output but if
> you wish to know more about these particular messages (well the
> "terminology" and the technical explanation):
> https://secure.wikimedia.org/wikipedia/en/wiki/Iommu
>
> https://secure.wikimedia.org/wikipedia/en/wiki/Aperture_%28computer_memory%29
>
> Some more digging (but I'm not sure it would help you)...
> http://bogdan.org.ua/2009/09/30/iommu-this-costs-you-64-mb-of-ram.html
>
> Best regards / MfG
>
> Peter K
>
Hi Peter,
thanks for the links and your explanations! :)
...will see, what I can do...
Keep hacking! ;)
Best regards,
mcc
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [gentoo-user] IOMMU and other oddities...
2011-08-09 5:32 [gentoo-user] IOMMU and other oddities meino.cramer
2011-08-09 5:58 ` Adam Carter
2011-08-09 8:58 ` pk
@ 2011-08-10 15:56 ` Volker Armin Hemmann
2 siblings, 0 replies; 6+ messages in thread
From: Volker Armin Hemmann @ 2011-08-10 15:56 UTC (permalink / raw
To: gentoo-user
Am Dienstag 09 August 2011, 07:32:34 schrieb meino.cramer@gmx.de:
> Hi,
>
> my PC consists -- beside other things -- of a AMD Phenom II X6 1090T,
> a ASUS Crossfire Formula IV and a NVidia GeForce GT 430 by MSI (PCIe).
> Furthermore I am using the vanilla Linux kernel 3.0.1. .
>
> I browsed through the output of dmesg and found these lines:
>
> Checking aperture...
> No AGP bridge found
> Node 0: aperture @ c4000000 size 32 MB
> Aperture pointing to e820 RAM. Ignoring.
> Your BIOS doesn't leave a aperture memory hole
> Please enable the IOMMU option in the BIOS setup
> This costs you 64 MB of RAM
> Mapping aperture over 65536 KB of RAM @ c4000000
>
> The kernel is not configured with any AGP-related (as far as I now)
> feature/config.
>
> Why does it look for an AGP-bridge???
>
> The dmesg says I should switch on IOMMU, which I did. But that does
> not impress the kernel that much since it still recommends to switch
> on IOMMU.
>
> What did I wrong here ?
>
> I want to fix issues, which may be reported by dmesg, so:
> Where can I find explanations to the dmesg output?
>
> For your information I attached the compressed dmesg output
> to this mail.
>
> Thank you very much for your help in advance!
> Best regards
> mcc
see also this:
http://marc.info/?l=linux-kernel&m=107764033904042&w=2
--
#163933
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2011-08-10 15:57 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2011-08-09 5:32 [gentoo-user] IOMMU and other oddities meino.cramer
2011-08-09 5:58 ` Adam Carter
2011-08-09 6:31 ` meino.cramer
2011-08-09 8:58 ` pk
2011-08-09 11:22 ` meino.cramer
2011-08-10 15:56 ` Volker Armin Hemmann
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox