Messages in this thread | | | Date | Sun, 6 Apr 2003 17:42:51 -0400 (EDT) | From | Rik van Riel <> | Subject | Re: subobj-rmap |
| |
On Sun, 6 Apr 2003, Martin J. Bligh wrote:
> Supposing we keep a list of areas (hung from the address_space) that > describes independant linear ranges of memory that have the same set > of vma's mapping them (call those subobjects). Each subobject has a > chain of vma's from it that are mapping that subobject. > > address_space ---> subobject ---> subobject ---> subobject ---> subobject > | | | | > v v v v > vma vma vma vma > | | | > v v v > vma vma vma > | | > v v > vma vma
OK, lets say we have a file of 1000 pages, or offsets 0 to 999, with the following mappings:
VMA A: 0-999 VMA B: 0-200 VMA C: 150-400 VMA D: 300-500 VMA E: 300-500 VMA F: 0-999
How would you describe these with independant regions ?
For VMAs D & E and A & F it's a no-brainer, but for Oracle shared memory you shouldn't assume that you have any similar mappings.
I don't see how the data structure you describe would allow us to efficiently select the subset of VMAs for which:
1) the start address is smaller than the address we want and 2) the end address is larger than the address we want
Then again, that might just be my lack of imagination.
cheers,
Rik
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |