lkml.org 
[lkml]   [2004]   [Dec]   [31]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: can you switch between GFP_ATOMIC and GFP_KERNEL?

    Oh, that's right.

    Stupid me =)

    Thanks,
    /*********************************/
    Michael R. Hines
    Grad Student, Florida State
    Dept. Computer Science
    http://www.cs.fsu.edu/~mhines/
    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
    >

    -
    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/

    \
     
     \ /
      Last update: 2005-03-22 14:09    [W:0.020 / U:30.232 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site