From: Peter Zijlstra <peterz@infradead.org>
To: Huang Ying <ying.huang@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
linux-kernel@vger.kernel.org, Andi Kleen <andi@firstfloor.org>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Subject: [PATCH 7/5] sched: Convert to use llist
Date: Mon, 12 Sep 2011 16:05:53 +0200 [thread overview]
Message-ID: <1315836353.26517.42.camel@twins> (raw)
In-Reply-To: <1315461646-1379-1-git-send-email-ying.huang@intel.com>
Subject: sched: Convert to use llist
From: Peter Zijlstra <a.p.zijlstra@chello.nl>
Date: Mon Sep 12 13:06:17 CEST 2011
Use the generic llist primitives..
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
---
include/linux/sched.h | 3 ++-
kernel/sched.c | 48 ++++++++++--------------------------------------
2 files changed, 12 insertions(+), 39 deletions(-)
Index: linux-2.6/include/linux/sched.h
===================================================================
--- linux-2.6.orig/include/linux/sched.h
+++ linux-2.6/include/linux/sched.h
@@ -90,6 +90,7 @@ struct sched_param {
#include <linux/task_io_accounting.h>
#include <linux/latencytop.h>
#include <linux/cred.h>
+#include <linux/llist.h>
#include <asm/processor.h>
@@ -1225,7 +1226,7 @@ struct task_struct {
unsigned int ptrace;
#ifdef CONFIG_SMP
- struct task_struct *wake_entry;
+ struct llist_node wake_entry;
int on_cpu;
#endif
int on_rq;
Index: linux-2.6/kernel/sched.c
===================================================================
--- linux-2.6.orig/kernel/sched.c
+++ linux-2.6/kernel/sched.c
@@ -702,7 +702,7 @@ struct rq {
#endif
#ifdef CONFIG_SMP
- struct task_struct *wake_list;
+ struct llist_head wake_list;
#endif
};
@@ -2698,42 +2698,26 @@ static int ttwu_remote(struct task_struc
}
#ifdef CONFIG_SMP
-static void sched_ttwu_do_pending(struct task_struct *list)
+static void sched_ttwu_pending(void)
{
struct rq *rq = this_rq();
+ struct llist_node *llist = llist_del_all(&rq->wake_list);
+ struct task_struct *p;
raw_spin_lock(&rq->lock);
- while (list) {
- struct task_struct *p = list;
- list = list->wake_entry;
+ while (llist) {
+ p = llist_entry(llist, struct task_struct, wake_entry);
+ llist = llist_next(llist);
ttwu_do_activate(rq, p, 0);
}
raw_spin_unlock(&rq->lock);
}
-#ifdef CONFIG_HOTPLUG_CPU
-
-static void sched_ttwu_pending(void)
-{
- struct rq *rq = this_rq();
- struct task_struct *list = xchg(&rq->wake_list, NULL);
-
- if (!list)
- return;
-
- sched_ttwu_do_pending(list);
-}
-
-#endif /* CONFIG_HOTPLUG_CPU */
-
void scheduler_ipi(void)
{
- struct rq *rq = this_rq();
- struct task_struct *list = xchg(&rq->wake_list, NULL);
-
- if (!list)
+ if (llist_empty(&this_rq()->wake_list))
return;
/*
@@ -2750,25 +2734,13 @@ void scheduler_ipi(void)
* somewhat pessimize the simple resched case.
*/
irq_enter();
- sched_ttwu_do_pending(list);
+ sched_ttwu_pending();
irq_exit();
}
static void ttwu_queue_remote(struct task_struct *p, int cpu)
{
- struct rq *rq = cpu_rq(cpu);
- struct task_struct *next = rq->wake_list;
-
- for (;;) {
- struct task_struct *old = next;
-
- p->wake_entry = next;
- next = cmpxchg(&rq->wake_list, old, p);
- if (next == old)
- break;
- }
-
- if (!next)
+ if (llist_add(&p->wake_entry, &cpu_rq(cpu)->wake_list))
smp_send_reschedule(cpu);
}
next prev parent reply other threads:[~2011-09-12 14:06 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-08 6:00 [PATCH -mm -v2 0/5] irq_work, Use llist in irq_work Huang Ying
2011-09-08 6:00 ` [PATCH -mm -v2 1/5] llist, Make all llist functions inline Huang Ying
2011-09-08 6:00 ` [PATCH -mm -v2 2/5] llist, Define macro to check NMI safe cmpxchg Huang Ying
2011-09-08 6:00 ` [PATCH -mm -v2 3/5] llist, Move cpu_relax after cmpxchg Huang Ying
2011-09-08 6:00 ` [PATCH -mm -v2 4/5] llist, Return whether list is empty before adding in llist_add Huang Ying
2011-09-08 6:00 ` [PATCH -mm -v2 5/5] irq_work, Use llist in irq_work Huang Ying
2011-09-12 14:05 ` [PATCH 6/5] llist: Add llist_next() Peter Zijlstra
2011-09-12 14:05 ` Peter Zijlstra [this message]
2011-09-12 14:05 ` [PATCH 8/5] llist: Remove cpu_relax() usage in cmpxchg loops Peter Zijlstra
2011-09-12 14:23 ` Andi Kleen
2011-09-12 14:23 ` Peter Zijlstra
2011-09-12 14:47 ` Mathieu Desnoyers
2011-09-12 15:09 ` Peter Zijlstra
2011-09-12 15:24 ` Peter Zijlstra
2011-09-12 16:38 ` Andi Kleen
2011-09-12 18:53 ` Peter Zijlstra
2011-09-12 14:26 ` Avi Kivity
2011-09-12 14:32 ` Peter Zijlstra
2011-09-13 11:43 ` Avi Kivity
2011-09-13 14:22 ` Peter Zijlstra
2011-09-13 14:51 ` Avi Kivity
2011-09-13 14:53 ` Peter Zijlstra
2011-09-12 14:06 ` [PATCH -mm -v2 0/5] irq_work, Use llist in irq_work Peter Zijlstra
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