RE: 2.6.29 git master and PAT problems
From: Pallipadi, Venkatesh
Date: Fri Apr 03 2009 - 09:58:25 EST
>-----Original Message-----
>From: Alessandro Suardi [mailto:alessandro.suardi@xxxxxxxxx]
>Sent: Friday, April 03, 2009 2:54 AM
>To: Pallipadi, Venkatesh
>Cc: Arkadiusz Miskiewicz; Siddha, Suresh B;
>linux-kernel@xxxxxxxxxxxxxxx; Jesse Barnes
>Subject: Re: 2.6.29 git master and PAT problems
>
>On Thu, Apr 2, 2009 at 2:49 AM, Pallipadi, Venkatesh
><venkatesh.pallipadi@xxxxxxxxx> wrote:
>> On Mon, Mar 30, 2009 at 05:28:15PM -0700, Pallipadi, Venkatesh wrote:
>>> On Mon, Mar 30, 2009 at 03:31:09PM -0700, Arkadiusz
>Miskiewicz wrote:
>>> > On Monday 30 of March 2009, Pallipadi, Venkatesh wrote:
>>> >
>>> > More info follows. Now I've switched to
>>> > e1c502482853f84606928f5a2f2eb6da1993cda1 which contains
>latest drm fixes and
>>> > now I get much lower numbers of PAT errors but still.
>>> >
>>> > > On Mon, 2009-03-30 at 14:31 -0700, Arkadiusz Miskiewicz wrote:
>>> > > > On Monday 30 of March 2009, Pallipadi, Venkatesh wrote:
>>> > > > > Patch here should get rid of these errors.
>>> > > > >
>>> > > > > http://marc.info/?l=linux-kernel&m=123788806506230&w=2
>>> > > > >
>>> > > > > The patch is in tip and on its way to upstream.
>>> > > >
>>> > > > The problem is that kernel I'm running already
>contains this patch (it's
>>> > > > merged already). Other ideas?
>>> > > >
>>> > > > ratelimiting that error is good IMO anyway.
>>> > >
>>> > > Rate limiting will just work around the problem here.
>Ideally we should
>>> > > never see these errors. So, it will be better if we can
>narrow down on
>>> > > the bug resulting in these error messages.
>>> >
>>> > Of course it's better. I'm saying that when these
>messages "fire" then it's
>>> > hard to do anything else on the system for a while until
>these stop.
>>> >
>>> > > Can you please send me the output of
>>> > > # cat /debug/x86/pat_memtype_list
>>> > > with debugfs mounted.
>>> > > and
>>> > > # cat /proc/mtrr
>>> >
>>>
>>> There seems to be two different problems here.
>>> - We should not have that many single page ranges reserved.
>That will cause a
>>> performance problem with drm even without the "freeing
>invalid type" error.
>>> - "freeing invalid type" error itself. Seems to be caused
>due to some
>>> unbalanced free along the drm path. We tried to find
>anything obvious in the
>>> code that may be causing problem here. But, haven't found
>anything so far.
>>> Will try to reproduce the problem internally and debug it further.
>>>
>>
>> OK. I think we have root caused the thinko that was resulting in
>> "freeing invalid type" error. Can you try the below test
>> patch. Patch is not final version and may need some cleanup.
>>
>> Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@xxxxxxxxx>
>> Signed-off-by: Suresh Siddha <suresh.b.siddha@xxxxxxxxx>
>>
>> diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
>> index 640339e..c161700 100644
>> --- a/arch/x86/mm/pat.c
>> +++ b/arch/x86/mm/pat.c
>> @@ -847,7 +847,8 @@ cleanup_ret:
>> * can be for the entire vma (in which case size can be zero).
>> */
>> void untrack_pfn_vma(struct vm_area_struct *vma, unsigned long pfn,
>> - unsigned long size)
>> + unsigned long size,
>> + unsigned long vstart, unsigned long vend)
>> {
>> unsigned long i;
>> resource_size_t paddr;
>> @@ -866,7 +867,7 @@ void untrack_pfn_vma(struct
>vm_area_struct *vma, unsigned long pfn,
>> return;
>> }
>>
>> - if (size != 0 && size != vma_size) {
>> + if (size != 0) {
>> /* free page by page, using pfn and size */
>> paddr = (resource_size_t)pfn << PAGE_SHIFT;
>> for (i = 0; i < size; i += PAGE_SIZE) {
>> @@ -874,9 +875,12 @@ void untrack_pfn_vma(struct
>vm_area_struct *vma, unsigned long pfn,
>> free_pfn_range(paddr, PAGE_SIZE);
>> }
>> } else {
>> - /* free entire vma, page by page, using the
>pfn from pte */
>> - for (i = 0; i < vma_size; i += PAGE_SIZE) {
>> - if (follow_phys(vma, vma_start + i,
>0, &prot, &paddr))
>> + /*
>> + * free vma range from vstart to end, page by page
>> + * using the pfn from pte
>> + */
>> + for (i = vstart; i < vend; i += PAGE_SIZE) {
>> + if (follow_phys(vma, i, 0, &prot, &paddr))
>> continue;
>>
>> free_pfn_range(paddr, PAGE_SIZE);
>> diff --git a/include/asm-generic/pgtable.h
>b/include/asm-generic/pgtable.h
>> index 8e6d0ca..a325dc1 100644
>> --- a/include/asm-generic/pgtable.h
>> +++ b/include/asm-generic/pgtable.h
>> @@ -328,7 +328,8 @@ static inline int
>track_pfn_vma_copy(struct vm_area_struct *vma)
>> * can be for the entire vma (in which case size can be zero).
>> */
>> static inline void untrack_pfn_vma(struct vm_area_struct *vma,
>> - unsigned long pfn,
>unsigned long size)
>> + unsigned long pfn, unsigned
>long size,
>> + unsigned long vstart,
>unsigned long vend)
>> {
>> }
>> #else
>> @@ -336,7 +337,8 @@ extern int track_pfn_vma_new(struct
>vm_area_struct *vma, pgprot_t *prot,
>> unsigned long pfn, unsigned
>long size);
>> extern int track_pfn_vma_copy(struct vm_area_struct *vma);
>> extern void untrack_pfn_vma(struct vm_area_struct *vma,
>unsigned long pfn,
>> - unsigned long size);
>> + unsigned long size,
>> + unsigned long vstart,
>unsigned long vend);
>> #endif
>>
>> #endif /* !__ASSEMBLY__ */
>> diff --git a/mm/memory.c b/mm/memory.c
>> index cf6873e..6e111c5 100644
>> --- a/mm/memory.c
>> +++ b/mm/memory.c
>> @@ -983,7 +983,7 @@ unsigned long unmap_vmas(struct
>mmu_gather **tlbp,
>> *nr_accounted += (end - start) >> PAGE_SHIFT;
>>
>> if (unlikely(is_pfn_mapping(vma)))
>> - untrack_pfn_vma(vma, 0, 0);
>> + untrack_pfn_vma(vma, 0, 0, start, end);
>>
>> while (start != end) {
>> if (!tlb_start_valid) {
>> @@ -1537,7 +1537,7 @@ int vm_insert_pfn(struct
>vm_area_struct *vma, unsigned long addr,
>> ret = insert_pfn(vma, addr, pfn, pgprot);
>>
>> if (ret)
>> - untrack_pfn_vma(vma, pfn, PAGE_SIZE);
>> + untrack_pfn_vma(vma, pfn, PAGE_SIZE, 0, 0);
>>
>> return ret;
>> }
>> @@ -1702,7 +1702,7 @@ int remap_pfn_range(struct
>vm_area_struct *vma, unsigned long addr,
>> } while (pgd++, addr = next, addr != end);
>>
>> if (err)
>> - untrack_pfn_vma(vma, pfn, PAGE_ALIGN(size));
>> + untrack_pfn_vma(vma, pfn, PAGE_ALIGN(size), 0, 0);
>>
>> return err;
>> }
>
>2.6.29-git9 plus the above patch still doesn't fix my Dell
>E6400 running
> Fedora 10 x86_64:
The patch here should get rid of the below msgs.
http://marc.info/?l=linux-kernel&m=123862741914199&w=2
Can you please test and check whether that resolves the problems?
The patch inline in this mail above was a test patch to debug the
another problem that only happens with recent X and that one we
are still debugging. So you can ignore the above patch for now.
Thanks,
Venki
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