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    SubjectRe: can you switch between GFP_ATOMIC and GFP_KERNEL?

    Oh, that's right.

    Stupid me =)

    Michael R. Hines
    Grad Student, Florida State
    Dept. Computer Science
    Jusqu'a ce que le futur vienne...

    On Fri, 31 Dec 2004, Roland Dreier wrote:

    > Michael> My question is, new sk_buffs are always allocated with
    > Michael> GFP_KERNEL and can be swapped out. Is it possible to
    > Michael> change the allocation status of already-allocated memory
    > Michael> to GFP_ATOMIC on the fly? (i.e. both the slab-cache
    > Michael> sk_buff header memory as well as the kmalloc'd data
    > Michael> area).
    > This question is ill-posed -- kernel memory can never be swapped out,
    > whether it's allocated with GFP_KERNEL or GFP_ATOMIC. The difference
    > between GFP_KERNEL and GFP_ATOMIC is whether the actual allocation can
    > sleep, that is:
    > foo = kmalloc(sizeof foo, GFP_ATOMIC); /* will not sleep */
    > foo = kmalloc(sizeof foo, GFP_KERNEL); /* can sleep */
    > However, whichever gfp flags are used to allocate memory, the memory
    > is the same once the allocation is done. Neither kmalloc'ed memory
    > nor sk_buffs will ever be swapped.
    > - Roland

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