Merge branch 'perf'
Signed-off-by: Avi Kivity <avi@redhat.com>
This commit is contained in:
commit
9beeaa2d68
157 changed files with 11107 additions and 6541 deletions
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@ -2077,49 +2077,6 @@ migrate_task(struct task_struct *p, int dest_cpu, struct migration_req *req)
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return 1;
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}
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/*
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* wait_task_context_switch - wait for a thread to complete at least one
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* context switch.
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*
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* @p must not be current.
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*/
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void wait_task_context_switch(struct task_struct *p)
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{
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unsigned long nvcsw, nivcsw, flags;
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int running;
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struct rq *rq;
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nvcsw = p->nvcsw;
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nivcsw = p->nivcsw;
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for (;;) {
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/*
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* The runqueue is assigned before the actual context
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* switch. We need to take the runqueue lock.
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*
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* We could check initially without the lock but it is
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* very likely that we need to take the lock in every
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* iteration.
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*/
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rq = task_rq_lock(p, &flags);
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running = task_running(rq, p);
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task_rq_unlock(rq, &flags);
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if (likely(!running))
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break;
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/*
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* The switch count is incremented before the actual
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* context switch. We thus wait for two switches to be
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* sure at least one completed.
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*/
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if ((p->nvcsw - nvcsw) > 1)
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break;
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if ((p->nivcsw - nivcsw) > 1)
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break;
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cpu_relax();
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}
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}
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/*
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* wait_task_inactive - wait for a thread to unschedule.
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*
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