lkml.org 
[lkml]   [2008]   [Feb]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    From
    SubjectRe: [PATCH] [1/1] CPA: Flush the caches when setting pages not present v2
    Date

    > This is suboptimal though, as it will trigger a wbinvd() everytime
    > when we hit a non present pte in a range, whether we did set the entry
    > in question to not present or not.

    Do you think that's common? I considered this while writing the code,
    but figured it was just a oddball case not worth caring about.

    DEBUG_PAGEALLOC does not call this normally anyways and people
    should not call this for unallocated mappings anyways.

    > The gart code unmapping is a special case. This only happens during
    > boot, so adding a wbinvd() to the gart code is solving this issue
    > without imposing it on other use cases.
    >
    > Another solution for this would be to change the mapping to uncached
    > before unmapping, so we could avoid the wbinvd() completely.

    That will work for pci-gart, but not for some future users of set_memory_np()
    I plan to submit (they run potentially with multiple CPUs online and doing callbacks
    there would be quite ugly). So I would prefer if you kept some variant of my original patch.

    -Andi



    \
     
     \ /
      Last update: 2008-02-11 18:39    [W:0.038 / U:0.632 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site