Re: Make yield_task_fair more efficient

From: Ingo Molnar
Date: Thu Feb 21 2008 - 01:04:55 EST



* Balbir Singh <balbir@xxxxxxxxxxxxxxxxxx> wrote:

> __pick_last_entity() walks the entire tree on O(lgn) time to find the
> rightmost entry. This patch makes the routine more efficient by
> reducing the cost of the lookup

hm, i'm not sure we want to do this: we'd be slowing down the fastpath
of all the other common scheduler functions, for the sake of a rarely
used (and broken ...) API: yield. And note that an rbtree walk is not
slow at all - if you are yielding frequently it's probably all cached.

Ingo
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