On Fri, Oct 26, 2012 at 11:30:27AM +0200, Stefani Seibold wrote:
> Am Freitag, den 26.10.2012, 15:56 +0800 schrieb Yuanhan Liu:
> > Say, if we want to allocate a filo with size of 6 bytes, it would be safer
> > to allocate 8 bytes instead of 4 bytes.
> > ----
> > I know it works with rounddown_pow_of_two as well, since size is maintained
> > in the kfifo internal part. But, I'm quite curious why Stefani chose
> > rounddown_pow_of_two. To reduce memory?
> >
>
> Yes, exactly, if a user do the wrong thing, than the user will get also
> a wrong result, and did not waste memory.
But, isn't it better to 'correct' it? ;-)
>
> But anyway, if the majority like this patch it is okay for me.
Sorry, do you mean you are OK with this patch?
Thanks,
Yuanhan Liu
> >
> > Cc: Stefani Seibold <stef...@seibold.net>
> > Cc: Andrew Morton <a...@linux-foundation.org>
> > Signed-off-by: Yuanhan Liu <yuanhan....@linux.intel.com>
> > ---
> > kernel/kfifo.c | 6 +++---
> > 1 files changed, 3 insertions(+), 3 deletions(-)
> >
> > diff --git a/kernel/kfifo.c b/kernel/kfifo.c
> > index 59dcf5b..0f78378 100644
> > --- a/kernel/kfifo.c
> > +++ b/kernel/kfifo.c
> > @@ -39,11 +39,11 @@ int __kfifo_alloc(struct __kfifo *fifo, unsigned int
> > size,
> > size_t esize, gfp_t gfp_mask)
> > {
> > /*
> > - * round down to the next power of 2, since our 'let the indices
> > + * round up to the next power of 2, since our 'let the indices
> > * wrap' technique works only in this case.
> > */
> > if (!is_power_of_2(size))
> > - size = rounddown_pow_of_two(size);
> > + size = roundup_pow_of_two(size);
> >
> > fifo->in = 0;
> > fifo->out = 0;
> > @@ -84,7 +84,7 @@ int __kfifo_init(struct __kfifo *fifo, void *buffer,
> > size /= esize;
> >
> > if (!is_power_of_2(size))
> > - size = rounddown_pow_of_two(size);
> > + size = roundup_pow_of_two(size);
> >
> > fifo->in = 0;
> > fifo->out = 0;
>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
