On Sep 13 2007 18:34, [EMAIL PROTECTED] wrote:
>Tomas M:
>> I noticed CONFIG_AUFS_BRANCH_MAX_32767 is still commented out in
>> local.mk so I didn't use it yet. Do you recommend it shouldn't be used
>> at all?
>
>It is up to linux memory allocation system.
>When you add a branch, aufs re-allocate some arrays for branch
>management. Basically an element in the array is a pointer.
>In x86 + 32bit + 4kb page size world, MAX_1023 means that aufs allocates
>one page at most for an array in branch management.
>As you can guess, on 64bit + 4kb page size system, MAX_511 will
>allocates one page at most.
Be aware, 64bit sometimes has an 8K (sparc64) or 16K (ia64) page size!
>To allocate large memory which requires several pages, is not
>preferable.
>If kmalloc() in linux kernel supports several 128kb(for 32bit) or
>256kb(for 64bit) allocations, you can enable MAX_32767 in safe.
>Actually, I don't know the exact limit of kmalloc. (I've heared it
>support upto 128kb). Additonally, I didn't think over 1024 branches is
>important. So I left this issue alone.
Just use vmalloc if it you need more. Unless you really need
contiguous pages that is. (probably not)
Jan
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