From nobody Tue Feb 10 21:39:06 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7DAC7EB64DA for ; Mon, 10 Jul 2023 20:04:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231534AbjGJUEG (ORCPT ); Mon, 10 Jul 2023 16:04:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57194 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229635AbjGJUEE (ORCPT ); Mon, 10 Jul 2023 16:04:04 -0400 Received: from mail-qv1-f50.google.com (mail-qv1-f50.google.com [209.85.219.50]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DAD66195 for ; Mon, 10 Jul 2023 13:04:02 -0700 (PDT) Received: by mail-qv1-f50.google.com with SMTP id 6a1803df08f44-634a3682c25so37773746d6.3 for ; Mon, 10 Jul 2023 13:04:02 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1689019442; x=1691611442; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=SWzC7HgThkzjSiE3ZBufE1vxY1hAeIuuMOLF9sjxPE0=; b=kH87JA4b76T58XQQzOBGQw/VLdfwrPJAcwP//ZFKpUfKRD+KN2HqKssKU88xrxXPo5 HziCc+E1/6P2Sk2oFF8SE1F9P+L+2jpP6ZgkwgpKoisr0O1scKVTehsfvLe2GPdqUBJc NHy9A/7Rknth+v70kesTsKX4nhlsDl5K9FL51kU/HZjShH2q99aovGynTDMjrbV4h4UE x4y3RyHWUgxjhM5UrvBC6E4GTkSgHRz7hO+Zj2tuf2no/tQ6FzC5srftSMrszphuYL1w BQyai0aiuVgP1r48iKQYP/EFqEt4V5duOJx3ER6KhaeG+wWeUZEsKmsxB+cFG11e1zjY tPHg== X-Gm-Message-State: ABy/qLb0MSHj6tyIsRGUxyRDes59pPnv7mTpMa3eMBRRgYMat6KcxoSI 9lzOtEIhMMfm4JzNlYY/toaJ5EznL6vAGSXH X-Google-Smtp-Source: APBJJlHOk/YX2kHwXmX6a/c+m31SkUZe7QmVT04a7vWIS8P0Ym3QowOgY8XuxmV53BfgSSjMKl3Wzg== X-Received: by 2002:a0c:f049:0:b0:630:1954:b30 with SMTP id b9-20020a0cf049000000b0063019540b30mr11942273qvl.9.1689019441553; Mon, 10 Jul 2023 13:04:01 -0700 (PDT) Received: from localhost ([2620:10d:c091:400::5:4850]) by smtp.gmail.com with ESMTPSA id m18-20020ae9e012000000b00765a676b75csm204370qkk.21.2023.07.10.13.04.01 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 10 Jul 2023 13:04:01 -0700 (PDT) From: David Vernet To: linux-kernel@vger.kernel.org Cc: mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com, gautham.shenoy@amd.com, kprateek.nayak@amd.com, aaron.lu@intel.com, clm@meta.com, tj@kernel.org, roman.gushchin@linux.dev, kernel-team@meta.com Subject: [PATCH v2 1/7] sched: Expose move_queued_task() from core.c Date: Mon, 10 Jul 2023 15:03:36 -0500 Message-Id: <20230710200342.358255-2-void@manifault.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230710200342.358255-1-void@manifault.com> References: <20230710200342.358255-1-void@manifault.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" The migrate_task_to() function exposed from kernel/sched/core.c migrates the current task, which is silently assumed to also be its first argument, to the specified CPU. The function uses stop_one_cpu() to migrate the task to the target CPU, which won't work if @p is not the current task as the stop_one_cpu() callback isn't invoked on remote CPUs. While this operation is useful for task_numa_migrate() in fair.c, it would be useful if move_queued_task() in core.c was given external linkage, as it actually can be used to migrate any task to a CPU. A follow-on patch will call move_queued_task() from fair.c when migrating a task in a shared runqueue to a remote CPU. Suggested-by: Peter Zijlstra Signed-off-by: David Vernet --- kernel/sched/core.c | 4 ++-- kernel/sched/sched.h | 3 +++ 2 files changed, 5 insertions(+), 2 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index c7db597e8175..167cd9f11ed0 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2493,8 +2493,8 @@ static inline bool is_cpu_allowed(struct task_struct = *p, int cpu) * * Returns (locked) new rq. Old rq's lock is released. */ -static struct rq *move_queued_task(struct rq *rq, struct rq_flags *rf, - struct task_struct *p, int new_cpu) +struct rq *move_queued_task(struct rq *rq, struct rq_flags *rf, + struct task_struct *p, int new_cpu) { lockdep_assert_rq_held(rq); =20 diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 50d4b61aef3a..94846c947d6e 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -1759,6 +1759,9 @@ init_numa_balancing(unsigned long clone_flags, struct= task_struct *p) =20 #ifdef CONFIG_SMP =20 + +extern struct rq *move_queued_task(struct rq *rq, struct rq_flags *rf, + struct task_struct *p, int new_cpu); static inline void queue_balance_callback(struct rq *rq, struct balance_callback *head, --=20 2.40.1