lkml.org 
[lkml]   [2012]   [Apr]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [x86 PAT PATCH 0/2] x86 PAT vm_flag code refactoring
    Suresh Siddha wrote:
    > Konstantin,
    >
    > On Sat, 2012-03-31 at 21:09 +0400, Konstantin Khlebnikov wrote:
    >> v2: Do not use batched pfn reserving for single-page VMA. This is not optimal
    >> and breaks something, because I see glitches on the screen with i915/drm driver.
    >> With this version glitches are gone, and I see the same regions in
    >> /sys/kernel/debug/x86/pat_memtype_list as before patch. So, please review this
    >> carefully, probably I'm wrong somewhere, or I have triggered some hidden bug.
    >
    > Actually it is not a hidden bug. In the original code, we were setting
    > VM_PFN_AT_MMAP only for remap_pfn_range() but not for the vm_insert_pfn().
    > Also the value of 'vm_pgoff' depends on the driver/mmap_region() in the case of
    > vm_insert_pfn(). But with your proposed code, you were setting
    > the VM_PAT for the single-page VMA also and end-up using wrong vm_pgoff in
    > untrack_pfn_vma().

    But I set correct vma->vm_pgoff together with VM_PAT. But, it shouldn't work if vma is expandable...

    >
    > We can simplify the track/untrack pfn routines and can remove the
    > dependency on vm_pgoff completely. Am appending a patch which does this
    > and also modified your x86 PAT patch based on this. Can you please
    > check and if you are ok, merge these bits with the rest of your patches.

    Ok, I'll checks this.

    >
    > thanks,
    > suresh
    > ---
    >
    > Konstantin Khlebnikov (1):
    > mm, x86, PAT: rework linear pfn-mmap tracking
    >
    > Suresh Siddha (1):
    > x86, pat: remove the dependency on 'vm_pgoff' in track/untrack pfn
    > vma routines
    >
    > arch/x86/mm/pat.c | 38 ++++++++++++++++++++++++--------------
    > include/asm-generic/pgtable.h | 4 ++--
    > include/linux/mm.h | 15 +--------------
    > mm/huge_memory.c | 7 +++----
    > mm/memory.c | 15 ++++++++-------
    > 5 files changed, 38 insertions(+), 41 deletions(-)
    >



    \
     
     \ /
      Last update: 2012-04-03 08:05    [W:4.926 / U:0.024 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site