mirror of https://gitee.com/openkylin/linux.git
sched: simplify sched_find_first_bit()
simplify sched_rt.c's sched_find_first_bit() function: there are only 100 RT priority levels left. Signed-off-by: Ingo Molnar <mingo@elte.hu>
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@ -6,28 +6,23 @@
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/*
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* Every architecture must define this function. It's the fastest
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* way of searching a 140-bit bitmap where the first 100 bits are
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* unlikely to be set. It's guaranteed that at least one of the 140
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* bits is cleared.
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* way of searching a 100-bit bitmap. It's guaranteed that at least
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* one of the 100 bits is cleared.
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*/
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static inline int sched_find_first_bit(const unsigned long *b)
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{
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#if BITS_PER_LONG == 64
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if (unlikely(b[0]))
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if (b[0])
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return __ffs(b[0]);
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if (likely(b[1]))
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return __ffs(b[1]) + 64;
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return __ffs(b[2]) + 128;
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return __ffs(b[1]) + 64;
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#elif BITS_PER_LONG == 32
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if (unlikely(b[0]))
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if (b[0])
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return __ffs(b[0]);
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if (unlikely(b[1]))
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if (b[1])
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return __ffs(b[1]) + 32;
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if (unlikely(b[2]))
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if (b[2])
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return __ffs(b[2]) + 64;
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if (b[3])
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return __ffs(b[3]) + 96;
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return __ffs(b[4]) + 128;
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return __ffs(b[3]) + 96;
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#else
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#error BITS_PER_LONG not defined
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#endif
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