From nobody Fri Dec 19 20:34:09 2025 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 067AA28DEE9 for ; Tue, 15 Apr 2025 10:25:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744712735; cv=none; b=m4VQhgfhpD6qS3YWR5g0SU60Ji6neQgtjnfoPsWG+fRfcRTEZJXLefSKSRJUWs50ZgTi5Lp38ZE+1u6XVOpKQE+Yv+txUTf5tUJFx/Xl1jYqLLz55WYyOObSFeCwBpplSmrVh6+1T6a1kjY2U5amjJMLAv9ib7samegiyY08X6A= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744712735; c=relaxed/simple; bh=tCUwMlpJ0PLdnGZk91rYJ+Bc4HAjRXkzO9BZr3rqAk8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=U4cQ22LGkNnzsTwS83BnzIBUlNA3qp0NZj5ISdRyutJKWmPhIgTgotrgcdOwYj9pcOFJKoJ/lN7QgcAdt+39vo3/xokToaaLVXwlcNXoKp+EInaLXFpIlYpXpsUR9myjopaFhsty83VFdiyr8F1LhyjCDbXLOXktNDr/cUzUqFY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=NdnNeQyh; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="NdnNeQyh" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1744712732; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=lsBUT7u//iK7sLk6YoMhB4VJF0MdfDCXAnznK/PHwiQ=; b=NdnNeQyh8LV36GhZ1Vskfxz0mpdmzrBWXr/FQUMLLa9iU9zAL/GcqBgPisSc6JrTgA1P7j abbY3UjgXf5snvdx2x55Wcf9RdHqFx5bEBpRrWyLM58/9bc09qVYjxuv+2/8f/5eSZ4yqg T3fNJFZNRLYoTa71dvuQnceSrMfH+0s= Received: from mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-111-L8lAnt0SPhGnrPk8ofJ7RQ-1; Tue, 15 Apr 2025 06:25:29 -0400 X-MC-Unique: L8lAnt0SPhGnrPk8ofJ7RQ-1 X-Mimecast-MFC-AGG-ID: L8lAnt0SPhGnrPk8ofJ7RQ_1744712728 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 59B421955BC9; Tue, 15 Apr 2025 10:25:28 +0000 (UTC) Received: from gmonaco-thinkpadt14gen3.rmtit.com (unknown [10.44.32.90]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 51EA71809B67; Tue, 15 Apr 2025 10:25:26 +0000 (UTC) From: Gabriele Monaco To: linux-kernel@vger.kernel.org, Frederic Weisbecker , Thomas Gleixner , Waiman Long Cc: Gabriele Monaco Subject: [PATCH v2 2/3] timers: Add the available mask in timer migration Date: Tue, 15 Apr 2025 12:25:03 +0200 Message-ID: <20250415102500.100415-7-gmonaco@redhat.com> In-Reply-To: <20250415102500.100415-5-gmonaco@redhat.com> References: <20250415102500.100415-5-gmonaco@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 Content-Type: text/plain; charset="utf-8" Keep track of the CPUs available for timer migration in a cpumask. This prepares the ground to generalise the concept of unavailable CPUs. Signed-off-by: Gabriele Monaco --- kernel/time/timer_migration.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/kernel/time/timer_migration.c b/kernel/time/timer_migration.c index 7efd897c79599..1fae38fbac8c2 100644 --- a/kernel/time/timer_migration.c +++ b/kernel/time/timer_migration.c @@ -422,6 +422,9 @@ static unsigned int tmigr_crossnode_level __read_mostly; =20 static DEFINE_PER_CPU(struct tmigr_cpu, tmigr_cpu); =20 +/* CPUs available for migration */ +static cpumask_var_t tmigr_available_cpumask; + #define TMIGR_NONE 0xFF #define BIT_CNT 8 =20 @@ -1449,6 +1452,7 @@ static int tmigr_cpu_unavailable(unsigned int cpu) raw_spin_lock_irq(&tmc->lock); tmc->available =3D false; WRITE_ONCE(tmc->wakeup, KTIME_MAX); + cpumask_clear_cpu(cpu, tmigr_available_cpumask); =20 /* * CPU has to handle the local events on his own, when on the way to @@ -1459,7 +1463,7 @@ static int tmigr_cpu_unavailable(unsigned int cpu) raw_spin_unlock_irq(&tmc->lock); =20 if (firstexp !=3D KTIME_MAX) { - migrator =3D cpumask_any_but(cpu_online_mask, cpu); + migrator =3D cpumask_any(tmigr_available_cpumask); work_on_cpu(migrator, tmigr_trigger_active, NULL); } =20 @@ -1480,6 +1484,7 @@ static int tmigr_cpu_available(unsigned int cpu) if (!tmc->idle) __tmigr_cpu_activate(tmc); tmc->available =3D true; + cpumask_set_cpu(cpu, tmigr_available_cpumask); raw_spin_unlock_irq(&tmc->lock); return 0; } @@ -1801,6 +1806,11 @@ static int __init tmigr_init(void) if (ncpus =3D=3D 1) return 0; =20 + if (!zalloc_cpumask_var(&tmigr_available_cpumask, GFP_KERNEL)) { + ret =3D -ENOMEM; + goto err; + } + /* * Calculate the required hierarchy levels. Unfortunately there is no * reliable information available, unless all possible CPUs have been --=20 2.49.0