[tip:sched/core] sched: Remove SYNC_WAKEUPS feature

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From: tip-bot for Mike Galbraith
Date: Thursday, March 11, 2010 - 11:33 am

Commit-ID:  c6ee36c423c3ed1fb86bb3eabba9fc256a300d16
Gitweb:     http://git.kernel.org/tip/c6ee36c423c3ed1fb86bb3eabba9fc256a300d16
Author:     Mike Galbraith <efault@gmx.de>
AuthorDate: Thu, 11 Mar 2010 17:16:43 +0100
Committer:  Ingo Molnar <mingo@elte.hu>
CommitDate: Thu, 11 Mar 2010 18:32:53 +0100

sched: Remove SYNC_WAKEUPS feature

Sync wakeups are critical functionality with a long history.  Remove it, we don't
need the branch or icache footprint.

Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1268301817.6785.47.camel@marge.simson.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 kernel/sched.c          |    3 ---
 kernel/sched_features.h |    8 --------
 2 files changed, 0 insertions(+), 11 deletions(-)

diff --git a/kernel/sched.c b/kernel/sched.c
index 16559de..cc6dc8c 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -2369,9 +2369,6 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state,
 	unsigned long flags;
 	struct rq *rq;
 
-	if (!sched_feat(SYNC_WAKEUPS))
-		wake_flags &= ~WF_SYNC;
-
 	this_cpu = get_cpu();
 
 	smp_wmb();
diff --git a/kernel/sched_features.h b/kernel/sched_features.h
index 1cb7c47..f54b6f9 100644
--- a/kernel/sched_features.h
+++ b/kernel/sched_features.h
@@ -23,14 +23,6 @@ SCHED_FEAT(WAKEUP_PREEMPT, 1)
 SCHED_FEAT(ASYM_GRAN, 1)
 
 /*
- * Use the SYNC wakeup hint, pipes and the likes use this to indicate
- * the remote end is likely to consume the data we just wrote, and
- * therefore has cache benefit from being placed on the same cpu, see
- * also AFFINE_WAKEUPS.
- */
-SCHED_FEAT(SYNC_WAKEUPS, 1)
-
-/*
  * Based on load and program behaviour, see if it makes sense to place
  * a newly woken task on the same cpu as the task that woke it --
  * improve cache locality. Typically used with SYNC wakeups as
--
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Messages in current thread:
[patch 0/12] sched: fastpath cycle recovery, Mike Galbraith, (Thu Mar 11, 2:49 am)
Re: [patch 1/12] sched: ratelimit nohz, Mike Galbraith, (Thu Mar 11, 2:50 am)
Re: [patch 2/12] sched: remove avg_wakeup, Mike Galbraith, (Thu Mar 11, 2:51 am)
Re: [patch 3/12] sched: remove avg_overlap, Mike Galbraith, (Thu Mar 11, 2:52 am)
Re: [patch 4/12] sched: cleanup/optimize clock updates, Mike Galbraith, (Thu Mar 11, 2:53 am)
Re: [patch 6/12] sched: fix select_idle_sibling(), Mike Galbraith, (Thu Mar 11, 2:56 am)
Re: [patch 7/12] sched: remove NORMALIZED_SLEEPER, Mike Galbraith, (Thu Mar 11, 2:57 am)
Re: [patch 8/12] sched: remove FAIR_SLEEPERS feature, Mike Galbraith, (Thu Mar 11, 2:58 am)
Re: [patch 9/12] sched: remove WAKEUP_SYNC feature, Mike Galbraith, (Thu Mar 11, 2:59 am)
Re: [patch 11/12] sched: remove ASYM_GRAN feature, Mike Galbraith, (Thu Mar 11, 3:01 am)
Re: [patch 10/12] sched: remove SYNC_WAKEUPS feature, Mike Galbraith, (Thu Mar 11, 3:03 am)
Re: [patch 12/12] sched: remove AFFINE_WAKEUPS feature, Mike Galbraith, (Thu Mar 11, 3:04 am)
[tip:sched/core] sched: Rate-limit nohz, tip-bot for Mike Gal ..., (Thu Mar 11, 11:30 am)
[tip:sched/core] sched: Remove avg_wakeup, tip-bot for Mike Gal ..., (Thu Mar 11, 11:30 am)
[tip:sched/core] sched: Remove avg_overlap, tip-bot for Mike Gal ..., (Thu Mar 11, 11:31 am)
[tip:sched/core] sched: Cleanup/optimize clock updates, tip-bot for Mike Gal ..., (Thu Mar 11, 11:31 am)
[tip:sched/core] sched: Tweak sched_latency and min_granul ..., tip-bot for Mike Gal ..., (Thu Mar 11, 11:31 am)
[tip:sched/core] sched: Fix select_idle_sibling(), tip-bot for Mike Gal ..., (Thu Mar 11, 11:32 am)
[tip:sched/core] sched: Remove NORMALIZED_SLEEPER, tip-bot for Mike Gal ..., (Thu Mar 11, 11:32 am)
[tip:sched/core] sched: Remove FAIR_SLEEPERS feature, tip-bot for Mike Gal ..., (Thu Mar 11, 11:32 am)
[tip:sched/core] sched: Remove WAKEUP_SYNC feature, tip-bot for Mike Gal ..., (Thu Mar 11, 11:32 am)
[tip:sched/core] sched: Remove SYNC_WAKEUPS feature, tip-bot for Mike Gal ..., (Thu Mar 11, 11:33 am)
[tip:sched/core] sched: Remove ASYM_GRAN feature, tip-bot for Mike Gal ..., (Thu Mar 11, 11:33 am)
[tip:sched/core] sched: Remove AFFINE_WAKEUPS feature, tip-bot for Mike Gal ..., (Thu Mar 11, 11:33 am)
Re: [tip:sched/core] sched: Remove AFFINE_WAKEUPS feature, Mike Galbraith, (Thu Mar 11, 9:37 pm)