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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