LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: Rik van Riel <riel@redhat.com>
Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
	Avi Kiviti <avi@redhat.com>,
	Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>,
	Mike Galbraith <efault@gmx.de>,
	Chris Wright <chrisw@sous-sol.org>,
	"Nakajima, Jun" <jun.nakajima@intel.com>
Subject: Re: [PATCH -v8a 3/7] sched: use a buddy to implement yield_task_fair
Date: Thu, 03 Feb 2011 13:58:34 +0100	[thread overview]
Message-ID: <1296737914.26581.365.camel@laptop> (raw)
In-Reply-To: <20110201095103.3a79e92a@annuminas.surriel.com>

On Tue, 2011-02-01 at 09:51 -0500, Rik van Riel wrote:
> -static void yield_task_fair(struct rq *rq)
> -{
> -       struct task_struct *curr = rq->curr;
> -       struct cfs_rq *cfs_rq = task_cfs_rq(curr);
> -       struct sched_entity *rightmost, *se = &curr->se;
> -
> -       /*
> -        * Are we the only task in the tree?
> -        */
> -       if (unlikely(rq->nr_running == 1))
> -               return;
> -
> -       clear_buddies(cfs_rq, se);
> -
> -       if (likely(!sysctl_sched_compat_yield) && curr->policy != SCHED_BATCH) {
> -               update_rq_clock(rq);
> -               /*
> -                * Update run-time statistics of the 'current'.
> -                */
> -               update_curr(cfs_rq);
> -
> -               return;
> -       }
> -       /*
> -        * Find the rightmost entry in the rbtree:
> -        */
> -       rightmost = __pick_last_entity(cfs_rq);
> -       /*
> -        * Already in the rightmost position?
> -        */
> -       if (unlikely(!rightmost || entity_before(rightmost, se)))
> -               return;
> -
> -       /*
> -        * Minimally necessary key value to be last in the tree:
> -        * Upon rescheduling, sched_class::put_prev_task() will place
> -        * 'current' within the tree based on its new key value.
> -        */
> -       se->vruntime = rightmost->vruntime + 1;
> -} 


This also wants the below bit in order to build without warnings for
SCHED_DEBUG=n:


---
Index: linux-2.6/kernel/sched_fair.c
===================================================================
--- linux-2.6.orig/kernel/sched_fair.c
+++ linux-2.6/kernel/sched_fair.c
@@ -431,6 +431,7 @@ static struct sched_entity *__pick_next_
 	return rb_entry(next, struct sched_entity, run_node);
 }
 
+#ifdef CONFIG_SCHED_DEBUG
 static struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq)
 {
 	struct rb_node *last = rb_last(&cfs_rq->tasks_timeline);
@@ -445,7 +446,6 @@ static struct sched_entity *__pick_last_
  * Scheduling class statistics methods:
  */
 
-#ifdef CONFIG_SCHED_DEBUG
 int sched_proc_update_handler(struct ctl_table *table, int write,
 		void __user *buffer, size_t *lenp,
 		loff_t *ppos)


  parent reply	other threads:[~2011-02-03 12:57 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-02-01 14:44 [PATCH -v8a 0/7] directed yield for Pause Loop Exiting Rik van Riel
2011-02-01 14:47 ` [PATCH -v8a 1/7] sched: check the right ->nr_running in yield_task_fair Rik van Riel
2011-02-03 14:11   ` [tip:sched/core] sched: Check the right ->nr_running in yield_task_fair() tip-bot for Rik van Riel
2011-02-01 14:48 ` [PATCH -v8a 2/7] sched: limit the scope of clear_buddies Rik van Riel
2011-02-03 14:11   ` [tip:sched/core] sched: Limit " tip-bot for Rik van Riel
2011-02-01 14:50 ` [PATCH -v8a 4/7] sched: Add yield_to(task, preempt) functionality Rik van Riel
2011-02-01 15:52   ` Peter Zijlstra
2011-02-03 12:58   ` Peter Zijlstra
2011-02-03 14:12   ` [tip:sched/core] " tip-bot for Mike Galbraith
2011-02-26  0:43     ` Venkatesh Pallipadi
2011-02-26  5:44       ` Rik van Riel
2011-02-28  9:26         ` Mike Galbraith
2011-03-02  0:28           ` [PATCH] sched: resched proper CPU on yield_to Venkatesh Pallipadi
2011-03-02  3:33             ` Rik van Riel
2011-03-02  3:37               ` Venkatesh Pallipadi
2011-03-02  3:52             ` Rik van Riel
2011-03-04 11:50             ` [tip:sched/core] sched: Resched proper CPU on yield_to() tip-bot for Venkatesh Pallipadi
2011-02-01 14:51 ` [PATCH -v8a 3/7] sched: use a buddy to implement yield_task_fair Rik van Riel
2011-02-01 15:53   ` Peter Zijlstra
2011-02-03 12:58   ` Peter Zijlstra [this message]
2011-02-03 14:12   ` [tip:sched/core] sched: Use a buddy to implement yield_task_fair() tip-bot for Rik van Riel
2011-02-01 14:51 ` [PATCH -v8a 5/7] export pid symbols needed for kvm_vcpu_on_spin Rik van Riel
2011-02-01 14:52 ` [PATCH -v8a 6/7] kvm: keep track of which task is running a KVM vcpu Rik van Riel
2011-02-01 14:53 ` [PATCH -v8a 7/7] kvm: use yield_to instead of sleep in kvm_vcpu_on_spin Rik van Riel
2011-02-07  9:08 ` [PATCH -v8a 0/7] directed yield for Pause Loop Exiting Avi Kivity

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1296737914.26581.365.camel@laptop \
    --to=a.p.zijlstra@chello.nl \
    --cc=avi@redhat.com \
    --cc=chrisw@sous-sol.org \
    --cc=efault@gmx.de \
    --cc=jun.nakajima@intel.com \
    --cc=kvm@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=riel@redhat.com \
    --cc=vatsa@linux.vnet.ibm.com \
    --subject='Re: [PATCH -v8a 3/7] sched: use a buddy to implement yield_task_fair' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).