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- Do not try to steal load from other CPUs if there was no contest switches on this CPU (i.e. it was idle all the time and woke up just for bus mastering or TLB shutdown). If current CPU was idle, then it is quite unlikely that some other CPU has load to steal. Under high I/O rate, when TLB shutdowns cause numerous CPU wakeups, on 24-CPU system load stealing code may consume up to 25% of all CPU time without giving any benefits. - Change code that implements spinning for load to restart spin in case of context switch. Previous code periodically called cpu_idle() even under high interrupt/context switch rate. - Rise spinning threshold to 10KHz, where it gives at least some effect that may worth consumed power. Reviewed by: jeff@
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