Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757618Ab2HVPBe (ORCPT ); Wed, 22 Aug 2012 11:01:34 -0400 Received: from mx1.redhat.com ([209.132.183.28]:22814 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757555Ab2HVPBK (ORCPT ); Wed, 22 Aug 2012 11:01:10 -0400 From: Andrea Arcangeli To: linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: Hillf Danton , Dan Smith , Linus Torvalds , Andrew Morton , Thomas Gleixner , Ingo Molnar , Paul Turner , Suresh Siddha , Mike Galbraith , "Paul E. McKenney" , Lai Jiangshan , Bharata B Rao , Lee Schermerhorn , Rik van Riel , Johannes Weiner , Srivatsa Vaddagiri , Christoph Lameter , Alex Shi , Mauricio Faria de Oliveira , Konrad Rzeszutek Wilk , Don Morris , Benjamin Herrenschmidt Subject: [PATCH 15/36] autonuma: alloc/free/init task_autonuma Date: Wed, 22 Aug 2012 16:58:59 +0200 Message-Id: <1345647560-30387-16-git-send-email-aarcange@redhat.com> In-Reply-To: <1345647560-30387-1-git-send-email-aarcange@redhat.com> References: <1345647560-30387-1-git-send-email-aarcange@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2293 Lines: 63 This is where the dynamically allocated task_autonuma structure is being handled. This is the structure holding the per-thread NUMA statistics generated by the NUMA hinting page faults. This per-thread NUMA statistical information is needed by sched_autonuma_balance to make optimal NUMA balancing decisions. It also contains the task_selected_nid which hints the stock CPU scheduler on the best NUMA node to schedule this thread on (as decided by sched_autonuma_balance). The reason for keeping this outside of the task_struct besides not using too much kernel stack, is to only allocate it on NUMA hardware. So the non NUMA hardware only pays the memory of a pointer in the kernel stack (which remains NULL at all times in that case). If the kernel is compiled with CONFIG_AUTONUMA=n, not even the pointer is allocated on the kernel stack of course. Signed-off-by: Andrea Arcangeli --- kernel/fork.c | 8 ++++++++ 1 files changed, 8 insertions(+), 0 deletions(-) diff --git a/kernel/fork.c b/kernel/fork.c index fbc67ee..9ba6e9b 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -209,6 +209,7 @@ void free_task(struct task_struct *tsk) { account_kernel_stack(tsk->stack, -1); arch_release_thread_info(tsk->stack); + free_task_autonuma(tsk); free_thread_info(tsk->stack); rt_mutex_debug_task_free(tsk); ftrace_graph_exit_task(tsk); @@ -264,6 +265,9 @@ void __init fork_init(unsigned long mempages) /* do the arch specific task caches init */ arch_task_cache_init(); + /* prepare task_autonuma for alloc_task_autonuma/free_task_autonuma */ + task_autonuma_init(); + /* * The default maximum number of threads is set to a safe * value: the thread structures can take up at most half @@ -310,6 +314,10 @@ static struct task_struct *dup_task_struct(struct task_struct *orig) if (err) goto free_ti; + if (unlikely(alloc_task_autonuma(tsk, orig, node))) + /* free_thread_info() undoes arch_dup_task_struct() too */ + goto free_ti; + tsk->stack = ti; setup_thread_stack(tsk, orig); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/