Messages in this thread | | | From | Linus Torvalds <> | Date | Tue, 26 Jul 2011 00:09:40 -0700 | Subject | Re: [GIT PULL] iscsi-target merge for v3.1-rc1 |
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On Mon, Jul 25, 2011 at 11:51 PM, Nicholas A. Bellinger <nab@linux-iscsi.org> wrote: > > How about the following to add a new DIV_ROUND_UP_ULL macro
Hmm.
> #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d)) > +#define DIV_ROUND_UP_ULL(n,d) ( \ > +{ \ > + unsigned long long _tmp = n, _off; \ > + int _res; \ > + /* Round up using asm/div64.h:do_div */ \ > + _off = do_div(_tmp, d); \ > + if (_off != 0) \ > + _tmp++; \ > + _res = _tmp; \ > +} \ > +)
That looks buggy. Why the "_res = _tmp" there? All that does is to truncate the result to "int", which looks bogus.
And it just looks unnecessarily complicated. Just a simple
#define DIV_ROUND_UP_ULL(ll,d) \ ({ unsigned long long _tmp = (ll)+(d)-1; do_div(_tmp, d); _tmp; })
looks like it would work and be simpler. Avoid the conditional, do the same "add 'd-1' thing as the regular ROUND_UP().
Untested. And not much thinking involved.
Linus -- 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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