lkml.org 
[lkml]   [2010]   [Mar]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[tip:sched/core] sched: Remove SYNC_WAKEUPS feature
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

\
 
 \ /
  Last update: 2010-03-11 19:37    [W:0.101 / U:13.224 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site