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    SubjectRe: [PATCH UPDATED 12/35] workqueue: update cwq alignement
    On Tue, Jun 29, 2010 at 10:12:13AM +0200, Tejun Heo wrote:
    > work->data field is used for two purposes. It points to cwq it's
    > queued on and the lower bits are used for flags. Currently, two bits
    > are reserved which is always safe as 4 byte alignment is guaranteed on
    > every architecture. However, future changes will need more flag bits.
    > On SMP, the percpu allocator is capable of honoring larger alignment
    > (there are other users which depend on it) and larger alignment works
    > just fine. On UP, percpu allocator is a thin wrapper around
    > kzalloc/kfree() and don't honor alignment request.
    > This patch introduces WORK_STRUCT_FLAG_BITS and implements
    > alloc/free_cwqs() which guarantees max(1 << WORK_STRUCT_FLAG_BITS,
    > __alignof__(unsigned long long) alignment both on SMP and UP. On SMP,
    > simply wrapping percpu allocator is enough. On UP, extra space is
    > allocated so that cwq can be aligned and the original pointer can be
    > stored after it which is used in the free path.
    > * Alignment problem on UP is reported by Michal Simek.
    > Signed-off-by: Tejun Heo <>
    > Cc: Christoph Lameter <>
    > Cc: Ingo Molnar <>
    > Cc: Frederic Weisbecker <>
    > Reported-by: Michal Simek <>
    > ---

    Your tree now builds well on x86-32. Thanks!

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