On Mon, Jan 30, 2012 at 12:37:34PM +0400, Dmitry Antipov wrote: > Fix pcpu_alloc() to return ZERO_SIZE_PTR if requested size is 0; > fix free_percpu() to check passed pointer with ZERO_OR_NULL_PTR. > > Signed-off-by: Dmitry Antipov <dmitry.anti...@linaro.org> > --- > mm/percpu.c | 16 +++++++++++----- > 1 files changed, 11 insertions(+), 5 deletions(-) > > diff --git a/mm/percpu.c b/mm/percpu.c > index f47af91..e903a19 100644 > --- a/mm/percpu.c > +++ b/mm/percpu.c > @@ -702,7 +702,8 @@ static struct pcpu_chunk *pcpu_chunk_addr_search(void > *addr) > * Does GFP_KERNEL allocation. > * > * RETURNS: > - * Percpu pointer to the allocated area on success, NULL on failure. > + * ZERO_SIZE_PTR if @size is zero, percpu pointer to the > + * allocated area on success or NULL on failure. > */ > static void __percpu *pcpu_alloc(size_t size, size_t align, bool reserved) > { > @@ -713,7 +714,10 @@ static void __percpu *pcpu_alloc(size_t size, size_t > align, bool reserved) > unsigned long flags; > void __percpu *ptr; > > - if (unlikely(!size || size > PCPU_MIN_UNIT_SIZE || align > PAGE_SIZE)) { > + if (unlikely(!size)) > + return ZERO_SIZE_PTR;
Percpu pointers are in a different address space and using ZERO_SIZE_PTR directly will trigger sparse address space warning. Also, I'm not entirely sure whether 16 is guaranteed to be unused in percpu address space (maybe it is but I don't think we have anything enforcing that). Thanks. -- tejun _______________________________________________ linaro-dev mailing list linaro-dev@lists.linaro.org http://lists.linaro.org/mailman/listinfo/linaro-dev