min_vruntime update when a task is sleeping/migrating

From	Pavan Kondeti <pkondeti@codeaurora.org>
Newsgroups	linux.kernel
Subject	min_vruntime update when a task is sleeping/migrating
Date	2017-02-23 07:20 +0100
Message-ID	<tdUUV-5HO-1@gated-at.bofh.it> (permalink)
Organization	linux.* mail to news gateway

Show all headers | View raw

Hi Peter,

The comment and the code around 2nd update_min_vruntime() call in
dequeue_entity() are not matching. If I understand commit b60205c7c558
("sched/fair: Fix min_vruntime tracking") correctly, the check is
inverted there. We want to update min_vruntime when a task is
sleeping/migrating. is my understanding right?

static void
dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
{

 <snip>
  /*
   * Now advance min_vruntime if @se was the entity holding it back,
   * except when: DEQUEUE_SAVE && !DEQUEUE_MOVE, in this case we'll be
   * put back on, and if we advance min_vruntime, we'll be placed back
   * further than we started -- ie. we'll be penalized.
   */
   if ((flags & (DEQUEUE_SAVE | DEQUEUE_MOVE)) == DEQUEUE_SAVE)
      update_min_vruntime(cfs_rq);
}

Thanks,
Pavan

-- 
Qualcomm India Private Limited, on behalf of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a
Linux Foundation Collaborative Project

Back to linux.kernel | Previous | Next — Next in thread | Find similar | Unroll thread

Thread

min_vruntime update when a task is sleeping/migrating Pavan Kondeti <pkondeti@codeaurora.org> - 2017-02-23 07:20 +0100
  Re: min_vruntime update when a task is sleeping/migrating Peter Zijlstra <peterz@infradead.org> - 2017-02-23 11:00 +0100

csiph-web