Messages in this thread | ![/](/images/icornerl.gif) | | Date | Wed, 12 Oct 2011 15:35:28 +0200 | Subject | Re: [PATCH 13/13] DRBD: Fix comparison always false warning due to long/long long compare | From | Geert Uytterhoeven <> |
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On Wed, Oct 12, 2011 at 14:27, Philipp Reisner <philipp.reisner@linbit.com> wrote: > From: David Howells <dhowells@redhat.com> > > Fix warnings of the following nature in the drbd header: > > In file included from drivers/block/drbd/drbd_bitmap.c:32: > drivers/block/drbd/drbd_int.h: In function 'drbd_get_syncer_progress': > drivers/block/drbd/drbd_int.h:2234: warning: comparison is always false due to limited range of data > > where mdev->rs_total (an unsigned long) is being compared to 1ULL << 32, which > is always false on a 32-bit machine.
But on 32-bit, unsigned long is never larger than UINT_MAX neither, so it doesn't really change anything??
> Signed-off-by: David Howells <dhowells@redhat.com> > Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> > > Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> > Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> > --- > drivers/block/drbd/drbd_int.h | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h > index ece2e4a..de42c7c 100644 > --- a/drivers/block/drbd/drbd_int.h > +++ b/drivers/block/drbd/drbd_int.h > @@ -2071,7 +2071,7 @@ static inline void drbd_get_syncer_progress(struct drbd_conf *mdev, > * Note: currently we don't support such large bitmaps on 32bit > * arch anyways, but no harm done to be prepared for it here. > */ > - unsigned int shift = mdev->rs_total >= (1ULL << 32) ? 16 : 10; > + unsigned int shift = mdev->rs_total > UINT_MAX ? 16 : 10; > unsigned long left = *bits_left >> shift; > unsigned long total = 1UL + (mdev->rs_total >> shift); > unsigned long tmp = 1000UL - left * 1000UL/total;
Gr{oetje,eeting}s,
Geert
-- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds -- 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/
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