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sched_ule(4): Pre-seed sched_random().

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I don't think it changes anything, but why not.

While there, make cpu_search_highest() use all 8 lower load bits for
noise, since it does not use cs_prefer and the code is not shared
with cpu_search_lowest() any more.

MFC after:	1 month
This commit is contained in:
Alexander Motin 2021-08-02 10:50:34 -04:00
parent 5c9cb96a23
commit ca34553b6f
1 changed files with 2 additions and 1 deletions
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3
sys/kern/sched_ule.c
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@ -739,7 +739,7 @@ cpu_search_highest(const struct cpu_group *cg, const struct cpu_search *s,
if (l < s->cs_limit || !tdq->tdq_transferable ||
!CPU_ISSET(c, s->cs_mask))
continue;
load -= sched_random() % 128;
load -= sched_random() % 256;
if (load > bload) {
bload = load;
r->cs_cpu = c;
@ -1416,6 +1416,7 @@ sched_setup_smp(void)
tdq->tdq_cg = smp_topo_find(cpu_top, i);
if (tdq->tdq_cg == NULL)
panic("Can't find cpu group for %d\n", i);
DPCPU_ID_SET(i, randomval, i * 69069 + 5);
}
PCPU_SET(sched, DPCPU_PTR(tdq));
balance_tdq = TDQ_SELF();