Commit ff80a77f authored by Mike Galbraith's avatar Mike Galbraith Committed by Ingo Molnar

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: default avatarIngo Molnar <mingo@elte.hu>
parent 5e7eaade
...@@ -6,28 +6,23 @@ ...@@ -6,28 +6,23 @@
/* /*
* Every architecture must define this function. It's the fastest * Every architecture must define this function. It's the fastest
* way of searching a 140-bit bitmap where the first 100 bits are * way of searching a 100-bit bitmap. It's guaranteed that at least
* unlikely to be set. It's guaranteed that at least one of the 140 * one of the 100 bits is cleared.
* bits is cleared.
*/ */
static inline int sched_find_first_bit(const unsigned long *b) static inline int sched_find_first_bit(const unsigned long *b)
{ {
#if BITS_PER_LONG == 64 #if BITS_PER_LONG == 64
if (unlikely(b[0])) if (b[0])
return __ffs(b[0]); return __ffs(b[0]);
if (likely(b[1]))
return __ffs(b[1]) + 64; return __ffs(b[1]) + 64;
return __ffs(b[2]) + 128;
#elif BITS_PER_LONG == 32 #elif BITS_PER_LONG == 32
if (unlikely(b[0])) if (b[0])
return __ffs(b[0]); return __ffs(b[0]);
if (unlikely(b[1])) if (b[1])
return __ffs(b[1]) + 32; return __ffs(b[1]) + 32;
if (unlikely(b[2])) if (b[2])
return __ffs(b[2]) + 64; return __ffs(b[2]) + 64;
if (b[3])
return __ffs(b[3]) + 96; return __ffs(b[3]) + 96;
return __ffs(b[4]) + 128;
#else #else
#error BITS_PER_LONG not defined #error BITS_PER_LONG not defined
#endif #endif
......
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