Messages in this thread Patch in this message | | | Date | Wed, 8 Apr 2009 15:37:16 -0700 | From | "Pallipadi, Venkatesh" <> | Subject | Re: 2.6.29 git master and PAT problems |
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On Wed, Apr 08, 2009 at 01:17:11AM -0700, Ingo Molnar wrote: > > * Arkadiusz Miskiewicz <a.miskiewicz@gmail.com> wrote: > > > On Wednesday 08 of April 2009, Pallipadi, Venkatesh wrote: > > > On Tue, Apr 07, 2009 at 02:12:28AM -0700, Arkadiusz Miskiewicz wrote: > > > > On Tuesday 07 of April 2009, Pallipadi, Venkatesh wrote: > > > > > On Thu, 2009-04-02 at 00:12 -0700, Arkadiusz Miskiewicz wrote: > > > > > > > > > > I was finally able to reproduce the problem of "freeing invalid > > > > > memtype" with upstream git kernel (commit 0221c81b1b) + latest xf86 > > > > > intel driver. But, with upstream + the patch I had sent you earlier in > > > > > this thread (http://marc.info/?l=linux-kernel&m=123863345520617&w=2) I > > > > > don't see those freeing invalid memtype errors anymore. > > > > > > > > > > Can you please double check with current git and that patch and let me > > > > > know if you are still seeing the problem. > > > > > > > > Latest linus tree + that patch (it's really applied here), xserver 1.6, > > > > libdrm from git master, intel driver from git master, previously mesa 7.4 > > > > (and 7.5 snap currently), tremolous.net 1.1.0 game (tremolous-smp > > > > binary), GM45 gpu. > > > > > > > > To reproduce I just need to run tremolous-smp and connect to some map. > > > > When map finishes loading I instantly get: > > [...] > > > > > OK. One more test patch below, applies over linus's git and you can ignore > > > the earlier patch. The patch below should get rid of the problem and > > > as it removes the track/untrack of vm_insert_pfn completely. This will > > > also eliminate the overhead of hundreds or thousands of entries in > > > pat_memtype_list. Can you please test it. > > > > With this patch I'm no longer able to reproduce problem. Thanks! > > Great, thanks! > > Venki, mind sending a patch with a proper changelog, Reported-by, > Tested-by tags, with Nick and Andrew Cc:-ed for the memory.c bits, > etc.?
Ingo,
Below is the cleaner version of the patch. It does not have any changes in mm as we are only removing the tracking inside the PAT code. I have left the generic mm interface as is, until we fully resolve the issue in future.
Thanks, Venki
Subject: [PATCH] x86, PAT: Remove page granularity tracking for vm_insert_pfn maps
Remove page level granularity track and untrack of vm_insert_pfn. memtype tracking at page granularity does not scale and cleaner approach would be for the driver to request a type for a bigger IO address range or PCI io memory range for that device, either at mmap time or driver init time and just use that type during vm_insert_pfn.
This patch just removes the track/untrack of vm_insert_pfn. That means we will be in same state as 2.6.28, with respect to these APIs. Newer APIs for the drivers to request a memtype for a bigger region is TBD and coming soon.
This change resolves the problem of too many single page entries in pat_memtype_list and "freeing invalid memtype" errors with i915, reported here. http://marc.info/?l=linux-kernel&m=123845244713183&w=2
Reported-by: Arkadiusz Miskiewicz <a.miskiewicz@gmail.com> Tested-by: Arkadiusz Miskiewicz <a.miskiewicz@gmail.com>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> --- arch/x86/mm/pat.c | 98 ++++++++++------------------------------------------ 1 files changed, 19 insertions(+), 79 deletions(-)
diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index 640339e..a8365c8 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -734,29 +734,28 @@ static void free_pfn_range(u64 paddr, unsigned long size) * * If the vma has a linear pfn mapping for the entire range, we get the prot * from pte and reserve the entire vma range with single reserve_pfn_range call. - * Otherwise, we reserve the entire vma range, my ging through the PTEs page - * by page to get physical address and protection. */ int track_pfn_vma_copy(struct vm_area_struct *vma) { - int retval = 0; - unsigned long i, j; resource_size_t paddr; unsigned long prot; - unsigned long vma_start = vma->vm_start; - unsigned long vma_end = vma->vm_end; - unsigned long vma_size = vma_end - vma_start; + unsigned long vma_size = vma->vm_end - vma->vm_start; pgprot_t pgprot; if (!pat_enabled) return 0; + /* + * For now, only handle remap_pfn_range() vmas where + * is_linear_pfn_mapping() == TRUE. Handling of + * vm_insert_pfn() is TBD. + */ if (is_linear_pfn_mapping(vma)) { /* * reserve the whole chunk covered by vma. We need the * starting address and protection from pte. */ - if (follow_phys(vma, vma_start, 0, &prot, &paddr)) { + if (follow_phys(vma, vma->vm_start, 0, &prot, &paddr)) { WARN_ON_ONCE(1); return -EINVAL; } @@ -764,28 +763,7 @@ int track_pfn_vma_copy(struct vm_area_struct *vma) return reserve_pfn_range(paddr, vma_size, &pgprot, 1); } - /* reserve entire vma page by page, using pfn and prot from pte */ - for (i = 0; i < vma_size; i += PAGE_SIZE) { - if (follow_phys(vma, vma_start + i, 0, &prot, &paddr)) - continue; - - pgprot = __pgprot(prot); - retval = reserve_pfn_range(paddr, PAGE_SIZE, &pgprot, 1); - if (retval) - goto cleanup_ret; - } return 0; - -cleanup_ret: - /* Reserve error: Cleanup partial reservation and return error */ - for (j = 0; j < i; j += PAGE_SIZE) { - if (follow_phys(vma, vma_start + j, 0, &prot, &paddr)) - continue; - - free_pfn_range(paddr, PAGE_SIZE); - } - - return retval; } /* @@ -795,50 +773,28 @@ cleanup_ret: * prot is passed in as a parameter for the new mapping. If the vma has a * linear pfn mapping for the entire range reserve the entire vma range with * single reserve_pfn_range call. - * Otherwise, we look t the pfn and size and reserve only the specified range - * page by page. - * - * Note that this function can be called with caller trying to map only a - * subrange/page inside the vma. */ int track_pfn_vma_new(struct vm_area_struct *vma, pgprot_t *prot, unsigned long pfn, unsigned long size) { - int retval = 0; - unsigned long i, j; - resource_size_t base_paddr; resource_size_t paddr; - unsigned long vma_start = vma->vm_start; - unsigned long vma_end = vma->vm_end; - unsigned long vma_size = vma_end - vma_start; + unsigned long vma_size = vma->vm_end - vma->vm_start; if (!pat_enabled) return 0; + /* + * For now, only handle remap_pfn_range() vmas where + * is_linear_pfn_mapping() == TRUE. Handling of + * vm_insert_pfn() is TBD. + */ if (is_linear_pfn_mapping(vma)) { /* reserve the whole chunk starting from vm_pgoff */ paddr = (resource_size_t)vma->vm_pgoff << PAGE_SHIFT; return reserve_pfn_range(paddr, vma_size, prot, 0); } - /* reserve page by page using pfn and size */ - base_paddr = (resource_size_t)pfn << PAGE_SHIFT; - for (i = 0; i < size; i += PAGE_SIZE) { - paddr = base_paddr + i; - retval = reserve_pfn_range(paddr, PAGE_SIZE, prot, 0); - if (retval) - goto cleanup_ret; - } return 0; - -cleanup_ret: - /* Reserve error: Cleanup partial reservation and return error */ - for (j = 0; j < i; j += PAGE_SIZE) { - paddr = base_paddr + j; - free_pfn_range(paddr, PAGE_SIZE); - } - - return retval; } /* @@ -849,39 +805,23 @@ cleanup_ret: void untrack_pfn_vma(struct vm_area_struct *vma, unsigned long pfn, unsigned long size) { - unsigned long i; resource_size_t paddr; - unsigned long prot; - unsigned long vma_start = vma->vm_start; - unsigned long vma_end = vma->vm_end; - unsigned long vma_size = vma_end - vma_start; + unsigned long vma_size = vma->vm_end - vma->vm_start; if (!pat_enabled) return; + /* + * For now, only handle remap_pfn_range() vmas where + * is_linear_pfn_mapping() == TRUE. Handling of + * vm_insert_pfn() is TBD. + */ if (is_linear_pfn_mapping(vma)) { /* free the whole chunk starting from vm_pgoff */ paddr = (resource_size_t)vma->vm_pgoff << PAGE_SHIFT; free_pfn_range(paddr, vma_size); return; } - - if (size != 0 && size != vma_size) { - /* free page by page, using pfn and size */ - paddr = (resource_size_t)pfn << PAGE_SHIFT; - for (i = 0; i < size; i += PAGE_SIZE) { - paddr = paddr + i; - 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)) - continue; - - free_pfn_range(paddr, PAGE_SIZE); - } - } } pgprot_t pgprot_writecombine(pgprot_t prot) -- 1.6.0.6
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