From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marcelo Tosatti Subject: [patch 07/18] sched: add notifier for cross-cpu migrations Date: Wed, 24 Oct 2012 11:13:47 -0200 Message-ID: <20121024131621.616518124@redhat.com> References: <20121024131340.742340256@redhat.com> Cc: johnstul@us.ibm.com, jeremy@goop.org, glommer@parallels.com, zamsden@gmail.com, gleb@redhat.com, avi@redhat.com, pbonzini@redhat.com, Marcelo Tosatti To: kvm@vger.kernel.org Return-path: Received: from mx1.redhat.com ([209.132.183.28]:54049 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756424Ab2JXNQ4 (ORCPT ); Wed, 24 Oct 2012 09:16:56 -0400 Content-Disposition: inline; filename=06-add-task-migration-notifier Sender: kvm-owner@vger.kernel.org List-ID: Originally from Jeremy Fitzhardinge. Signed-off-by: Marcelo Tosatti Index: vsyscall/include/linux/sched.h =================================================================== --- vsyscall.orig/include/linux/sched.h +++ vsyscall/include/linux/sched.h @@ -107,6 +107,14 @@ extern unsigned long this_cpu_load(void) extern void calc_global_load(unsigned long ticks); extern void update_cpu_load_nohz(void); +/* Notifier for when a task gets migrated to a new CPU */ +struct task_migration_notifier { + struct task_struct *task; + int from_cpu; + int to_cpu; +}; +extern void register_task_migration_notifier(struct notifier_block *n); + extern unsigned long get_parent_ip(unsigned long addr); struct seq_file; Index: vsyscall/kernel/sched/core.c =================================================================== --- vsyscall.orig/kernel/sched/core.c +++ vsyscall/kernel/sched/core.c @@ -922,6 +922,13 @@ void check_preempt_curr(struct rq *rq, s rq->skip_clock_update = 1; } +static ATOMIC_NOTIFIER_HEAD(task_migration_notifier); + +void register_task_migration_notifier(struct notifier_block *n) +{ + atomic_notifier_chain_register(&task_migration_notifier, n); +} + #ifdef CONFIG_SMP void set_task_cpu(struct task_struct *p, unsigned int new_cpu) { @@ -952,8 +959,16 @@ void set_task_cpu(struct task_struct *p, trace_sched_migrate_task(p, new_cpu); if (task_cpu(p) != new_cpu) { + struct task_migration_notifier tmn; + p->se.nr_migrations++; perf_sw_event(PERF_COUNT_SW_CPU_MIGRATIONS, 1, NULL, 0); + + tmn.task = p; + tmn.from_cpu = task_cpu(p); + tmn.to_cpu = new_cpu; + + atomic_notifier_call_chain(&task_migration_notifier, 0, &tmn); } __set_task_cpu(p, new_cpu);