Regression from 3.4.9 to 3.4.16 "stable" kernel

Regression from 3.4.9 to 3.4.16 "stable" kernel

[Mark Lord]

My server here runs the 3.4.xx series of "stable" kernels.
Until today, it was running 3.4.9.
Today I tried to upgrade it to 3.4.16.
It hangs in setup.c.

I've isolated the fault down to this specific change
that was made between 3.4.9 and 3.4.16.
Reverting this change allows the system to boot/run normally again.


--- linux-3.4.9/arch/x86/kernel/setup.c	2012-08-15 11:17:17.000000000 -0400
+++ linux-3.4.16/arch/x86/kernel/setup.c	2012-10-28 13:36:33.000000000 -0400
@@ -927,8 +927,21 @@

 #ifdef CONFIG_X86_64
 	if (max_pfn > max_low_pfn) {
-		max_pfn_mapped = init_memory_mapping(1UL<<32,
-						     max_pfn<<PAGE_SHIFT);
+		int i;
+		for (i = 0; i < e820.nr_map; i++) {
+			struct e820entry *ei = &e820.map[i];
+
+			if (ei->addr + ei->size <= 1UL << 32)
+				continue;
+
+			if (ei->type == E820_RESERVED)
+				continue;
+
+			max_pfn_mapped = init_memory_mapping(
+				ei->addr < 1UL << 32 ? 1UL << 32 : ei->addr,
+				ei->addr + ei->size);
+		}
+
 		/* can we preseve max_low_pfn ?*/
 		max_low_pfn = max_pfn;
 	}

Re: Regression from 3.4.9 to 3.4.16 "stable" kernel

[Willy Tarreau]

On Mon, Oct 29, 2012 at 12:03:55AM -0400, Mark Lord wrote:
> My server here runs the 3.4.xx series of "stable" kernels.
> Until today, it was running 3.4.9.
> Today I tried to upgrade it to 3.4.16.
> It hangs in setup.c.
> 
> I've isolated the fault down to this specific change
> that was made between 3.4.9 and 3.4.16.
> Reverting this change allows the system to boot/run normally again.
> 
> 
> --- linux-3.4.9/arch/x86/kernel/setup.c	2012-08-15 11:17:17.000000000 -0400
> +++ linux-3.4.16/arch/x86/kernel/setup.c	2012-10-28 13:36:33.000000000 -0400
> @@ -927,8 +927,21 @@
> 
>  #ifdef CONFIG_X86_64
>  	if (max_pfn > max_low_pfn) {
> -		max_pfn_mapped = init_memory_mapping(1UL<<32,
> -						     max_pfn<<PAGE_SHIFT);
> +		int i;
> +		for (i = 0; i < e820.nr_map; i++) {
> +			struct e820entry *ei = &e820.map[i];
> +
> +			if (ei->addr + ei->size <= 1UL << 32)
> +				continue;
> +
> +			if (ei->type == E820_RESERVED)
> +				continue;
> +
> +			max_pfn_mapped = init_memory_mapping(
> +				ei->addr < 1UL << 32 ? 1UL << 32 : ei->addr,
> +				ei->addr + ei->size);
> +		}
> +
>  		/* can we preseve max_low_pfn ?*/
>  		max_low_pfn = max_pfn;
>  	}

For the record, it is this commit introduced in 3.4.16 :

commit efd5fa0c1a1d1b46846ea6e8d1a783d0d8a6a721
Author: Jacob Shin <jacob.shin@amd.com>
Date:   Thu Oct 20 16:15:26 2011 -0500

    x86: Exclude E820_RESERVED regions and memory holes above 4 GB from direct mapping.
    
    commit 1bbbbe779aabe1f0768c2bf8f8c0a5583679b54a upstream.
    
    On systems with very large memory (1 TB in our case), BIOS may report a
    reserved region or a hole in the E820 map, even above the 4 GB range. Exclude
    these from the direct mapping.
    
    [ hpa: this should be done not just for > 4 GB but for everything above the legacy
      region (1 MB), at the very least.  That, however, turns out to require significant
      restructuring.  That work is well underway, but is not suitable for rc/stable. ]
    
    Signed-off-by: Jacob Shin <jacob.shin@amd.com>
    Link: http://lkml.kernel.org/r/1319145326-13902-1-git-send-email-jacob.shin@amd.com
    Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Willy

Re: Regression from 3.4.9 to 3.4.16 "stable" kernel

[Mark Lord]

On 12-10-29 02:46 AM, Willy Tarreau wrote:
> On Mon, Oct 29, 2012 at 12:03:55AM -0400, Mark Lord wrote:
>> My server here runs the 3.4.xx series of "stable" kernels.
>> Until today, it was running 3.4.9.
>> Today I tried to upgrade it to 3.4.16.
>> It hangs in setup.c.
>>
>> I've isolated the fault down to this specific change
>> that was made between 3.4.9 and 3.4.16.
>> Reverting this change allows the system to boot/run normally again.
>>
>>
>> --- linux-3.4.9/arch/x86/kernel/setup.c	2012-08-15 11:17:17.000000000 -0400
>> +++ linux-3.4.16/arch/x86/kernel/setup.c	2012-10-28 13:36:33.000000000 -0400
>> @@ -927,8 +927,21 @@
>>
>>  #ifdef CONFIG_X86_64
>>  	if (max_pfn > max_low_pfn) {
>> -		max_pfn_mapped = init_memory_mapping(1UL<<32,
>> -						     max_pfn<<PAGE_SHIFT);
>> +		int i;
>> +		for (i = 0; i < e820.nr_map; i++) {
>> +			struct e820entry *ei = &e820.map[i];
>> +
>> +			if (ei->addr + ei->size <= 1UL << 32)
>> +				continue;
>> +
>> +			if (ei->type == E820_RESERVED)
>> +				continue;
>> +
>> +			max_pfn_mapped = init_memory_mapping(
>> +				ei->addr < 1UL << 32 ? 1UL << 32 : ei->addr,
>> +				ei->addr + ei->size);
>> +		}
>> +
>>  		/* can we preseve max_low_pfn ?*/
>>  		max_low_pfn = max_pfn;
>>  	}
> 
> For the record, it is this commit introduced in 3.4.16 :
> 
> commit efd5fa0c1a1d1b46846ea6e8d1a783d0d8a6a721
> Author: Jacob Shin <jacob.shin@amd.com>
> Date:   Thu Oct 20 16:15:26 2011 -0500
> 
>     x86: Exclude E820_RESERVED regions and memory holes above 4 GB from direct mapping.
>     
>     commit 1bbbbe779aabe1f0768c2bf8f8c0a5583679b54a upstream.
>     
>     On systems with very large memory (1 TB in our case), BIOS may report a
>     reserved region or a hole in the E820 map, even above the 4 GB range. Exclude
>     these from the direct mapping.
>     
>     [ hpa: this should be done not just for > 4 GB but for everything above the legacy
>       region (1 MB), at the very least.  That, however, turns out to require significant
>       restructuring.  That work is well underway, but is not suitable for rc/stable. ]
>     
>     Signed-off-by: Jacob Shin <jacob.shin@amd.com>
>     Link: http://lkml.kernel.org/r/1319145326-13902-1-git-send-email-jacob.shin@amd.com
>     Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
>     Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> 
> Willy


Thanks, Willy.

I've also now downloaded linux-3.7.0-rc3, and it boots/runs without need for patching.
So there's a fix somewhere in between that perhaps could also get backported to -stable.

-ml

Re: Regression from 3.4.9 to 3.4.16 "stable" kernel

[Mark Lord]

On 12-10-29 10:22 AM, Mark Lord wrote:
> On 12-10-29 02:46 AM, Willy Tarreau wrote:
>> On Mon, Oct 29, 2012 at 12:03:55AM -0400, Mark Lord wrote:
>>> My server here runs the 3.4.xx series of "stable" kernels.
>>> Until today, it was running 3.4.9.
>>> Today I tried to upgrade it to 3.4.16.
>>> It hangs in setup.c.
>>>
>>> I've isolated the fault down to this specific change
>>> that was made between 3.4.9 and 3.4.16.
>>> Reverting this change allows the system to boot/run normally again.
..
>> For the record, it is this commit introduced in 3.4.16 :
>>
>> commit efd5fa0c1a1d1b46846ea6e8d1a783d0d8a6a721
>> Author: Jacob Shin <jacob.shin@amd.com>
>> Date:   Thu Oct 20 16:15:26 2011 -0500
>>
>>     x86: Exclude E820_RESERVED regions and memory holes above 4 GB from direct mapping.
>>     
>>     commit 1bbbbe779aabe1f0768c2bf8f8c0a5583679b54a upstream.
>>     
>>     On systems with very large memory (1 TB in our case), BIOS may report a
>>     reserved region or a hole in the E820 map, even above the 4 GB range. Exclude
>>     these from the direct mapping.
>>     
>>     [ hpa: this should be done not just for > 4 GB but for everything above the legacy
>>       region (1 MB), at the very least.  That, however, turns out to require significant
>>       restructuring.  That work is well underway, but is not suitable for rc/stable. ]
>>     
>>     Signed-off-by: Jacob Shin <jacob.shin@amd.com>
>>     Link: http://lkml.kernel.org/r/1319145326-13902-1-git-send-email-jacob.shin@amd.com
>>     Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
>>     Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
..
> I've also now downloaded linux-3.7.0-rc3, and it boots/runs without need for patching.
> So there's a fix somewhere in between that perhaps could also get backported to -stable.
..

Heh.. except that kernel has its own issues -- hangs in some kind of screen loop
in the Radeon code (?) when trying to shutdown.  ctrl-alt-sysrq s+u+s+b gets out of that,
but it hangs in a similar fashion during the subsequent reboot.

A full power-off was required to get the Radeon video to behave so I could reboot
the system with 3.4.16 again.  I'm not going to pursue that issue for now, though.

Re: Regression from 3.4.9 to 3.4.16 "stable" kernel

[Ben Hutchings]

[-- Attachment #1: Type: text/plain, Size: 3320 bytes --]

On Mon, 2012-10-29 at 10:22 -0400, Mark Lord wrote:
> On 12-10-29 02:46 AM, Willy Tarreau wrote:
> > On Mon, Oct 29, 2012 at 12:03:55AM -0400, Mark Lord wrote:
> >> My server here runs the 3.4.xx series of "stable" kernels.
> >> Until today, it was running 3.4.9.
> >> Today I tried to upgrade it to 3.4.16.
> >> It hangs in setup.c.
> >>
> >> I've isolated the fault down to this specific change
> >> that was made between 3.4.9 and 3.4.16.
> >> Reverting this change allows the system to boot/run normally again.
> >>
> >>
> >> --- linux-3.4.9/arch/x86/kernel/setup.c	2012-08-15 11:17:17.000000000 -0400
> >> +++ linux-3.4.16/arch/x86/kernel/setup.c	2012-10-28 13:36:33.000000000 -0400
> >> @@ -927,8 +927,21 @@
> >>
> >>  #ifdef CONFIG_X86_64
> >>  	if (max_pfn > max_low_pfn) {
> >> -		max_pfn_mapped = init_memory_mapping(1UL<<32,
> >> -						     max_pfn<<PAGE_SHIFT);
> >> +		int i;
> >> +		for (i = 0; i < e820.nr_map; i++) {
> >> +			struct e820entry *ei = &e820.map[i];
> >> +
> >> +			if (ei->addr + ei->size <= 1UL << 32)
> >> +				continue;
> >> +
> >> +			if (ei->type == E820_RESERVED)
> >> +				continue;
> >> +
> >> +			max_pfn_mapped = init_memory_mapping(
> >> +				ei->addr < 1UL << 32 ? 1UL << 32 : ei->addr,
> >> +				ei->addr + ei->size);
> >> +		}
> >> +
> >>  		/* can we preseve max_low_pfn ?*/
> >>  		max_low_pfn = max_pfn;
> >>  	}
> > 
> > For the record, it is this commit introduced in 3.4.16 :
> > 
> > commit efd5fa0c1a1d1b46846ea6e8d1a783d0d8a6a721
> > Author: Jacob Shin <jacob.shin@amd.com>
> > Date:   Thu Oct 20 16:15:26 2011 -0500
> > 
> >     x86: Exclude E820_RESERVED regions and memory holes above 4 GB from direct mapping.
> >     
> >     commit 1bbbbe779aabe1f0768c2bf8f8c0a5583679b54a upstream.
> >     
> >     On systems with very large memory (1 TB in our case), BIOS may report a
> >     reserved region or a hole in the E820 map, even above the 4 GB range. Exclude
> >     these from the direct mapping.
> >     
> >     [ hpa: this should be done not just for > 4 GB but for everything above the legacy
> >       region (1 MB), at the very least.  That, however, turns out to require significant
> >       restructuring.  That work is well underway, but is not suitable for rc/stable. ]
> >     
> >     Signed-off-by: Jacob Shin <jacob.shin@amd.com>
> >     Link: http://lkml.kernel.org/r/1319145326-13902-1-git-send-email-jacob.shin@amd.com
> >     Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
> >     Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> > 
> > Willy
> 
> 
> Thanks, Willy.
> 
> I've also now downloaded linux-3.7.0-rc3, and it boots/runs without need for patching.
> So there's a fix somewhere in between that perhaps could also get backported to -stable.

Might well be:

commit 1f2ff682ac951ed82cc043cf140d2851084512df
Author: Yinghai Lu <yinghai@kernel.org>
Date:   Mon Oct 22 16:35:18 2012 -0700

    x86, mm: Use memblock memory loop instead of e820_RAM

However I'm not sure that this loop is correct either.  Yinghai, does
your version definitely iterate in increasing pfn order?  If not then
the max_pfn_mapped assignment must be conditional.

Ben.

-- 
Ben Hutchings
Humans are not rational beings; they are rationalising beings.

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Re: Regression from 3.4.9 to 3.4.16 "stable" kernel

[Jacob Shin]

On Mon, Oct 29, 2012 at 02:40:58PM +0000, Ben Hutchings wrote:
> On Mon, 2012-10-29 at 10:22 -0400, Mark Lord wrote:
> > On 12-10-29 02:46 AM, Willy Tarreau wrote:
> > > On Mon, Oct 29, 2012 at 12:03:55AM -0400, Mark Lord wrote:
> > >> My server here runs the 3.4.xx series of "stable" kernels.
> > >> Until today, it was running 3.4.9.
> > >> Today I tried to upgrade it to 3.4.16.
> > >> It hangs in setup.c.
> > >>
> > >> I've isolated the fault down to this specific change
> > >> that was made between 3.4.9 and 3.4.16.
> > >> Reverting this change allows the system to boot/run normally again.
> > >>
> > >>
> > >> --- linux-3.4.9/arch/x86/kernel/setup.c	2012-08-15 11:17:17.000000000 -0400
> > >> +++ linux-3.4.16/arch/x86/kernel/setup.c	2012-10-28 13:36:33.000000000 -0400
> > >> @@ -927,8 +927,21 @@
> > >>
> > >>  #ifdef CONFIG_X86_64
> > >>  	if (max_pfn > max_low_pfn) {
> > >> -		max_pfn_mapped = init_memory_mapping(1UL<<32,
> > >> -						     max_pfn<<PAGE_SHIFT);
> > >> +		int i;
> > >> +		for (i = 0; i < e820.nr_map; i++) {
> > >> +			struct e820entry *ei = &e820.map[i];
> > >> +
> > >> +			if (ei->addr + ei->size <= 1UL << 32)
> > >> +				continue;
> > >> +
> > >> +			if (ei->type == E820_RESERVED)
> > >> +				continue;
> > >> +
> > >> +			max_pfn_mapped = init_memory_mapping(
> > >> +				ei->addr < 1UL << 32 ? 1UL << 32 : ei->addr,
> > >> +				ei->addr + ei->size);
> > >> +		}
> > >> +
> > >>  		/* can we preseve max_low_pfn ?*/
> > >>  		max_low_pfn = max_pfn;
> > >>  	}
> > > 
> > > For the record, it is this commit introduced in 3.4.16 :
> > > 
> > > commit efd5fa0c1a1d1b46846ea6e8d1a783d0d8a6a721
> > > Author: Jacob Shin <jacob.shin@amd.com>
> > > Date:   Thu Oct 20 16:15:26 2011 -0500
> > > 
> > >     x86: Exclude E820_RESERVED regions and memory holes above 4 GB from direct mapping.
> > >     
> > >     commit 1bbbbe779aabe1f0768c2bf8f8c0a5583679b54a upstream.
> > >     
> > >     On systems with very large memory (1 TB in our case), BIOS may report a
> > >     reserved region or a hole in the E820 map, even above the 4 GB range. Exclude
> > >     these from the direct mapping.
> > >     
> > >     [ hpa: this should be done not just for > 4 GB but for everything above the legacy
> > >       region (1 MB), at the very least.  That, however, turns out to require significant
> > >       restructuring.  That work is well underway, but is not suitable for rc/stable. ]
> > >     
> > >     Signed-off-by: Jacob Shin <jacob.shin@amd.com>
> > >     Link: http://lkml.kernel.org/r/1319145326-13902-1-git-send-email-jacob.shin@amd.com
> > >     Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
> > >     Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> > > 
> > > Willy
> > 
> > 
> > Thanks, Willy.
> > 
> > I've also now downloaded linux-3.7.0-rc3, and it boots/runs without need for patching.
> > So there's a fix somewhere in between that perhaps could also get backported to -stable.
> 
> Might well be:
> 
> commit 1f2ff682ac951ed82cc043cf140d2851084512df
> Author: Yinghai Lu <yinghai@kernel.org>
> Date:   Mon Oct 22 16:35:18 2012 -0700
> 
>     x86, mm: Use memblock memory loop instead of e820_RAM
> 
> However I'm not sure that this loop is correct either.  Yinghai, does
> your version definitely iterate in increasing pfn order?  If not then
> the max_pfn_mapped assignment must be conditional.

Hi, I believe these two commits in mainline should fix Alexander's failing
machien:

844ab6f993b1d32eb40512503d35ff6ad0c57030
f82f64dd9f485e13f29f369772d4a0e868e5633a

This thread has some more details:

https://lkml.org/lkml/2012/10/21/157

Sorry, and thanks!

> 
> Ben.
> 
> -- 
> Ben Hutchings
> Humans are not rational beings; they are rationalising beings.

Re: Regression from 3.4.9 to 3.4.16 "stable" kernel

[Greg Kroah-Hartman]

On Mon, Oct 29, 2012 at 09:47:22AM -0500, Jacob Shin wrote:
> On Mon, Oct 29, 2012 at 02:40:58PM +0000, Ben Hutchings wrote:
> > On Mon, 2012-10-29 at 10:22 -0400, Mark Lord wrote:
> > > On 12-10-29 02:46 AM, Willy Tarreau wrote:
> > > > On Mon, Oct 29, 2012 at 12:03:55AM -0400, Mark Lord wrote:
> > > >> My server here runs the 3.4.xx series of "stable" kernels.
> > > >> Until today, it was running 3.4.9.
> > > >> Today I tried to upgrade it to 3.4.16.
> > > >> It hangs in setup.c.
> > > >>
> > > >> I've isolated the fault down to this specific change
> > > >> that was made between 3.4.9 and 3.4.16.
> > > >> Reverting this change allows the system to boot/run normally again.
> > > >>
> > > >>
> > > >> --- linux-3.4.9/arch/x86/kernel/setup.c	2012-08-15 11:17:17.000000000 -0400
> > > >> +++ linux-3.4.16/arch/x86/kernel/setup.c	2012-10-28 13:36:33.000000000 -0400
> > > >> @@ -927,8 +927,21 @@
> > > >>
> > > >>  #ifdef CONFIG_X86_64
> > > >>  	if (max_pfn > max_low_pfn) {
> > > >> -		max_pfn_mapped = init_memory_mapping(1UL<<32,
> > > >> -						     max_pfn<<PAGE_SHIFT);
> > > >> +		int i;
> > > >> +		for (i = 0; i < e820.nr_map; i++) {
> > > >> +			struct e820entry *ei = &e820.map[i];
> > > >> +
> > > >> +			if (ei->addr + ei->size <= 1UL << 32)
> > > >> +				continue;
> > > >> +
> > > >> +			if (ei->type == E820_RESERVED)
> > > >> +				continue;
> > > >> +
> > > >> +			max_pfn_mapped = init_memory_mapping(
> > > >> +				ei->addr < 1UL << 32 ? 1UL << 32 : ei->addr,
> > > >> +				ei->addr + ei->size);
> > > >> +		}
> > > >> +
> > > >>  		/* can we preseve max_low_pfn ?*/
> > > >>  		max_low_pfn = max_pfn;
> > > >>  	}
> > > > 
> > > > For the record, it is this commit introduced in 3.4.16 :
> > > > 
> > > > commit efd5fa0c1a1d1b46846ea6e8d1a783d0d8a6a721
> > > > Author: Jacob Shin <jacob.shin@amd.com>
> > > > Date:   Thu Oct 20 16:15:26 2011 -0500
> > > > 
> > > >     x86: Exclude E820_RESERVED regions and memory holes above 4 GB from direct mapping.
> > > >     
> > > >     commit 1bbbbe779aabe1f0768c2bf8f8c0a5583679b54a upstream.
> > > >     
> > > >     On systems with very large memory (1 TB in our case), BIOS may report a
> > > >     reserved region or a hole in the E820 map, even above the 4 GB range. Exclude
> > > >     these from the direct mapping.
> > > >     
> > > >     [ hpa: this should be done not just for > 4 GB but for everything above the legacy
> > > >       region (1 MB), at the very least.  That, however, turns out to require significant
> > > >       restructuring.  That work is well underway, but is not suitable for rc/stable. ]
> > > >     
> > > >     Signed-off-by: Jacob Shin <jacob.shin@amd.com>
> > > >     Link: http://lkml.kernel.org/r/1319145326-13902-1-git-send-email-jacob.shin@amd.com
> > > >     Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
> > > >     Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> > > > 
> > > > Willy
> > > 
> > > 
> > > Thanks, Willy.
> > > 
> > > I've also now downloaded linux-3.7.0-rc3, and it boots/runs without need for patching.
> > > So there's a fix somewhere in between that perhaps could also get backported to -stable.
> > 
> > Might well be:
> > 
> > commit 1f2ff682ac951ed82cc043cf140d2851084512df
> > Author: Yinghai Lu <yinghai@kernel.org>
> > Date:   Mon Oct 22 16:35:18 2012 -0700
> > 
> >     x86, mm: Use memblock memory loop instead of e820_RAM
> > 
> > However I'm not sure that this loop is correct either.  Yinghai, does
> > your version definitely iterate in increasing pfn order?  If not then
> > the max_pfn_mapped assignment must be conditional.
> 
> Hi, I believe these two commits in mainline should fix Alexander's failing
> machien:
> 
> 844ab6f993b1d32eb40512503d35ff6ad0c57030
> f82f64dd9f485e13f29f369772d4a0e868e5633a
> 
> This thread has some more details:
> 
> https://lkml.org/lkml/2012/10/21/157
> 
> Sorry, and thanks!

Thanks, I've queued these up now.

greg k-h

Re: Regression from 3.4.9 to 3.4.16 "stable" kernel

[Jacob Shin]

On Mon, Oct 29, 2012 at 09:58:23AM -0700, Greg Kroah-Hartman wrote:
> On Mon, Oct 29, 2012 at 09:47:22AM -0500, Jacob Shin wrote:
> > On Mon, Oct 29, 2012 at 02:40:58PM +0000, Ben Hutchings wrote:
> > > On Mon, 2012-10-29 at 10:22 -0400, Mark Lord wrote:
> > > > On 12-10-29 02:46 AM, Willy Tarreau wrote:
> > > > > On Mon, Oct 29, 2012 at 12:03:55AM -0400, Mark Lord wrote:
> > > > >> My server here runs the 3.4.xx series of "stable" kernels.
> > > > >> Until today, it was running 3.4.9.
> > > > >> Today I tried to upgrade it to 3.4.16.
> > > > >> It hangs in setup.c.
> > > > >>
> > > > >> I've isolated the fault down to this specific change
> > > > >> that was made between 3.4.9 and 3.4.16.
> > > > >> Reverting this change allows the system to boot/run normally again.
> > > > >>
> > > > >>
> > > > >> --- linux-3.4.9/arch/x86/kernel/setup.c	2012-08-15 11:17:17.000000000 -0400
> > > > >> +++ linux-3.4.16/arch/x86/kernel/setup.c	2012-10-28 13:36:33.000000000 -0400
> > > > >> @@ -927,8 +927,21 @@
> > > > >>
> > > > >>  #ifdef CONFIG_X86_64
> > > > >>  	if (max_pfn > max_low_pfn) {
> > > > >> -		max_pfn_mapped = init_memory_mapping(1UL<<32,
> > > > >> -						     max_pfn<<PAGE_SHIFT);
> > > > >> +		int i;
> > > > >> +		for (i = 0; i < e820.nr_map; i++) {
> > > > >> +			struct e820entry *ei = &e820.map[i];
> > > > >> +
> > > > >> +			if (ei->addr + ei->size <= 1UL << 32)
> > > > >> +				continue;
> > > > >> +
> > > > >> +			if (ei->type == E820_RESERVED)
> > > > >> +				continue;
> > > > >> +
> > > > >> +			max_pfn_mapped = init_memory_mapping(
> > > > >> +				ei->addr < 1UL << 32 ? 1UL << 32 : ei->addr,
> > > > >> +				ei->addr + ei->size);
> > > > >> +		}
> > > > >> +
> > > > >>  		/* can we preseve max_low_pfn ?*/
> > > > >>  		max_low_pfn = max_pfn;
> > > > >>  	}
> > > > > 
> > > > > For the record, it is this commit introduced in 3.4.16 :
> > > > > 
> > > > > commit efd5fa0c1a1d1b46846ea6e8d1a783d0d8a6a721
> > > > > Author: Jacob Shin <jacob.shin@amd.com>
> > > > > Date:   Thu Oct 20 16:15:26 2011 -0500
> > > > > 
> > > > >     x86: Exclude E820_RESERVED regions and memory holes above 4 GB from direct mapping.
> > > > >     
> > > > >     commit 1bbbbe779aabe1f0768c2bf8f8c0a5583679b54a upstream.
> > > > >     
> > > > >     On systems with very large memory (1 TB in our case), BIOS may report a
> > > > >     reserved region or a hole in the E820 map, even above the 4 GB range. Exclude
> > > > >     these from the direct mapping.
> > > > >     
> > > > >     [ hpa: this should be done not just for > 4 GB but for everything above the legacy
> > > > >       region (1 MB), at the very least.  That, however, turns out to require significant
> > > > >       restructuring.  That work is well underway, but is not suitable for rc/stable. ]
> > > > >     
> > > > >     Signed-off-by: Jacob Shin <jacob.shin@amd.com>
> > > > >     Link: http://lkml.kernel.org/r/1319145326-13902-1-git-send-email-jacob.shin@amd.com
> > > > >     Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
> > > > >     Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> > > > > 
> > > > > Willy
> > > > 
> > > > 
> > > > Thanks, Willy.
> > > > 
> > > > I've also now downloaded linux-3.7.0-rc3, and it boots/runs without need for patching.
> > > > So there's a fix somewhere in between that perhaps could also get backported to -stable.
> > > 
> > > Might well be:
> > > 
> > > commit 1f2ff682ac951ed82cc043cf140d2851084512df
> > > Author: Yinghai Lu <yinghai@kernel.org>
> > > Date:   Mon Oct 22 16:35:18 2012 -0700
> > > 
> > >     x86, mm: Use memblock memory loop instead of e820_RAM
> > > 
> > > However I'm not sure that this loop is correct either.  Yinghai, does
> > > your version definitely iterate in increasing pfn order?  If not then
> > > the max_pfn_mapped assignment must be conditional.
> > 
> > Hi, I believe these two commits in mainline should fix Alexander's failing
> > machien:
> > 
> > 844ab6f993b1d32eb40512503d35ff6ad0c57030
> > f82f64dd9f485e13f29f369772d4a0e868e5633a
> > 
> > This thread has some more details:
> > 
> > https://lkml.org/lkml/2012/10/21/157
> > 
> > Sorry, and thanks!
> 
> Thanks, I've queued these up now.

Thanks,

And also unrelated to Alexander's panic, but related to the commit in question
1bbbbe779aabe1f0768c2bf8f8c0a5583679b54a

These two commits from Yinghai should also be backported into stable, or I
think it is already in progress (I saw an email out to Yinghai saying that the
patch did not apply cleanly, and needs to be manually backported):

6ede1fd3cb404c0016de6ac529df46d561bd558b
1f2ff682ac951ed82cc043cf140d2851084512df

Right Yinghai?

Thanks!

-Jacob

> 
> greg k-h
> 

Re: Regression from 3.4.9 to 3.4.16 "stable" kernel

[Mark Lord]

There's something else very wrong when going from 3.4.9 to 3.4.16.
I've done it on two machines here, one the AMD-450 server (64-bit),
and the other my main notebook (Core2duo 32-bit-PAE).

Both systems feel much more sluggish than usual with 3.4.16 running.
Reverted them both back to earlier kernels (3.4.9, 3.4.4-PAE),
and the usual responsive feel has returned.

Vague, I know, but something bad happened in there somewhere.

Cheers

Re: Regression from 3.4.9 to 3.4.16 "stable" kernel

[Greg Kroah-Hartman]

On Mon, Oct 29, 2012 at 07:00:54PM -0400, Mark Lord wrote:
> There's something else very wrong when going from 3.4.9 to 3.4.16.
> I've done it on two machines here, one the AMD-450 server (64-bit),
> and the other my main notebook (Core2duo 32-bit-PAE).
> 
> Both systems feel much more sluggish than usual with 3.4.16 running.
> Reverted them both back to earlier kernels (3.4.9, 3.4.4-PAE),
> and the usual responsive feel has returned.
> 
> Vague, I know, but something bad happened in there somewhere.

That's too vague for me to do anything with, sorry.  Bisection would be
good if you can figure out how to measure this.

greg k-h

Re: Regression from 3.4.9 to 3.4.16 "stable" kernel

[Yinghai Lu]

On Mon, Oct 29, 2012 at 4:03 PM, Greg Kroah-Hartman
<gregkh@linuxfoundation.org> wrote:
> On Mon, Oct 29, 2012 at 07:00:54PM -0400, Mark Lord wrote:
>> Both systems feel much more sluggish than usual with 3.4.16 running.
>> Reverted them both back to earlier kernels (3.4.9, 3.4.4-PAE),
>> and the usual responsive feel has returned.
>>
>> Vague, I know, but something bad happened in there somewhere.
>
> That's too vague for me to do anything with, sorry.  Bisection would be
> good if you can figure out how to measure this.

yes, at least you can post boot log of working kernel and not working kernel.
then we could figure out if there is any corner case is not handled or
uncovered.

Re: Regression from 3.4.9 to 3.4.16 "stable" kernel

[Mark Lord]

On 12-10-29 07:03 PM, Greg Kroah-Hartman wrote:
> On Mon, Oct 29, 2012 at 07:00:54PM -0400, Mark Lord wrote:
>> There's something else very wrong when going from 3.4.9 to 3.4.16.
>> I've done it on two machines here, one the AMD-450 server (64-bit),
>> and the other my main notebook (Core2duo 32-bit-PAE).
>>
>> Both systems feel much more sluggish than usual with 3.4.16 running.
>> Reverted them both back to earlier kernels (3.4.9, 3.4.4-PAE),
>> and the usual responsive feel has returned.
>>
>> Vague, I know, but something bad happened in there somewhere.
> 
> That's too vague for me to do anything with, sorry.  Bisection would be
> good if you can figure out how to measure this.

Well, I'd bet Donkeys to Daises that reverting the kernel/sched.c changes
will probably fix the responsiveness, but I haven't done that yet.
I've lost enough time already debugging the other issues.

This is more just an indication that perhaps -stable patches need better review
than they're getting.  Take the setup.c breakage: as soon as I pointed it out,
a few people jumped in with knowledge that it was broken, and that patches
existed to fix it.

That kind of thing should be happening before a -stable release,
though I don't know how you would get the Right People to look
at this stuff then rather than after the fact.  Maybe a topic
for a future kernel summit or something.

Best wishes.
-ml

Re: Regression from 3.4.9 to 3.4.16 "stable" kernel

[Greg Kroah-Hartman]

On Tue, Oct 30, 2012 at 12:53:06AM -0400, Mark Lord wrote:
> On 12-10-29 07:03 PM, Greg Kroah-Hartman wrote:
> > On Mon, Oct 29, 2012 at 07:00:54PM -0400, Mark Lord wrote:
> >> There's something else very wrong when going from 3.4.9 to 3.4.16.
> >> I've done it on two machines here, one the AMD-450 server (64-bit),
> >> and the other my main notebook (Core2duo 32-bit-PAE).
> >>
> >> Both systems feel much more sluggish than usual with 3.4.16 running.
> >> Reverted them both back to earlier kernels (3.4.9, 3.4.4-PAE),
> >> and the usual responsive feel has returned.
> >>
> >> Vague, I know, but something bad happened in there somewhere.
> > 
> > That's too vague for me to do anything with, sorry.  Bisection would be
> > good if you can figure out how to measure this.
> 
> Well, I'd bet Donkeys to Daises that reverting the kernel/sched.c changes
> will probably fix the responsiveness, but I haven't done that yet.
> I've lost enough time already debugging the other issues.
> 
> This is more just an indication that perhaps -stable patches need better review
> than they're getting.  Take the setup.c breakage: as soon as I pointed it out,
> a few people jumped in with knowledge that it was broken, and that patches
> existed to fix it.

There will always be bugs, fixing them quickly is the best that we can
do.

> That kind of thing should be happening before a -stable release,
> though I don't know how you would get the Right People to look
> at this stuff then rather than after the fact.  Maybe a topic
> for a future kernel summit or something.

I send patches to everyone involved, and there's a -rc period where
people are _supposed_ to test things out.  If you know of a better way
to get other people to test and review, please let me know, this is the
best that we have come up with so far.

thanks,

greg k-h

Re: Regression from 3.4.9 to 3.4.16 "stable" kernel

[Yinghai Lu]

On Mon, Oct 29, 2012 at 7:40 AM, Ben Hutchings <ben@decadent.org.uk> wrote:
> However I'm not sure that this loop is correct either.  Yinghai, does
> your version definitely iterate in increasing pfn order?  If not then
> the max_pfn_mapped assignment must be conditional.

yes, memblock is in order.

Yinghai