why are there some redundant variable definition
in [Kernel]
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From: Parmenides on 25 Jul 2010 17:30 Hi, I have read a macro like this ++++ include/linux/kernel.h 159: #define min_t(type,x,y) \ 160: ({ type __x = (x); type __y = (y); __x < __y ? __x: __y; }) ++++ net/ipv4/tcp_output.c 654: int full_space = min_t(int, tp->window_clamp, tcp_full_space(sk)); The definitions of __x and __y are somewhat redundant. I think a more -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Randy Dunlap on 25 Jul 2010 17:50
On Mon, 26 Jul 2010 05:29:04 +0800 Parmenides wrote: > Hi, > I have read a macro like this > ++++ include/linux/kernel.h > 159: #define min_t(type,x,y) \ > 160: ({ type __x = (x); type __y = (y); __x < __y ? __x: __y; }) > ++++ net/ipv4/tcp_output.c > 654: int full_space = min_t(int, tp->window_clamp, tcp_full_space(sk)); > > The definitions of __x and __y are somewhat redundant. I think a more > -- The local variables __x and __y are used so that 'x' and 'y' are not re-evaluated multiple times. That could be a problem if either one of them is an expression. Anything else? --- ~Randy *** Remember to use Documentation/SubmitChecklist when testing your code *** -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |