Relocate sched_random() within the SMP section.
Place sched_random nearer to where it's first used: moving the code nearer to where it is used makes the code easier to read and we can reduce the initial "#ifdef SMP" island. Reword a little the comment and clean some whitespaces while here.
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Notes:
svn2git
2020-12-20 02:59:44 +00:00
svn path=/head/; revision=285243
@ -356,26 +356,6 @@ SDT_PROBE_DEFINE(sched, , , remain__cpu);
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SDT_PROBE_DEFINE2(sched, , , surrender, "struct thread *",
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"struct proc *");
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#ifdef SMP
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/*
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* We need some randomness. Implement the classic Linear Congruential
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* generator X_{n+1}=(aX_n+c) mod m. These values are optimized for
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* m = 2^32, a = 69069 and c = 5. We only return the upper 16 bits
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* of the random state (in the low bits of our answer) to return
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* the maximum randomness.
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*/
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static uint32_t
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sched_random(void)
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{
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uint32_t *rndptr;
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rndptr = DPCPU_PTR(randomval);
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*rndptr = *rndptr * 69069 + 5;
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return (*rndptr >> 16);
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}
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#endif
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/*
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* Print the threads waiting on a run-queue.
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*/
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@ -625,6 +605,24 @@ tdq_setlowpri(struct tdq *tdq, struct thread *ctd)
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}
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#ifdef SMP
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/*
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* We need some randomness. Implement a classic Linear Congruential
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* Generator X_{n+1}=(aX_n+c) mod m. These values are optimized for
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* m = 2^32, a = 69069 and c = 5. We only return the upper 16 bits
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* of the random state (in the low bits of our answer) to keep
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* the maximum randomness.
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*/
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static uint32_t
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sched_random(void)
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{
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uint32_t *rndptr;
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rndptr = DPCPU_PTR(randomval);
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*rndptr = *rndptr * 69069 + 5;
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return (*rndptr >> 16);
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}
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struct cpu_search {
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cpuset_t cs_mask;
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u_int cs_prefer;
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