From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 ACBF7298CDE for ; Wed, 30 Jul 2025 13:12:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753881148; cv=none; b=eVvUVsdktOlBgOuo651I/cka5ptwY5w9mNcWD1NpUMouhKHetYI+EU/f484sYueWzHdI6AygAsx7hGoDHDTCYjKIHUGbER/iYf1uWP32cqwcHAAqR2NOcBGS3p/FED282tsfdUrbuBYRDxt26IFuz3BgW+EeGRRY+9OaiL8mnCw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753881148; c=relaxed/simple; bh=7jbDhUlFF30PiIJELshkrtatGYe9wKCF2+c930Z4KeQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Mq5hDRqcfQxYNK/REJBZ7XGgGYJWzAUj75Z0+7hlSoWRT4cr5PCV6bz5aNNT2mSmOzVRjFQKcPRJ4Dugo9K7lIgyjEnjfnXJCN98+o0VZBsJby/FDStSyTmbZ2QHAeC4wJQID7mbqsElYDNf9UcU7ltmhCnfSCOBPB/tXuaaBQ8= 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=G8zd8pzA; arc=none smtp.client-ip=170.10.133.124 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="G8zd8pzA" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1753881145; 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=8EZo5sKoFUiGYEeLlNYLLUQnWNaHyvL5KIMLU8+hm1g=; b=G8zd8pzAHZMOze59xZAsR5GKfZHWz51Ir5IPgL/FvKh5djQ9Wsu337BoKl65ng6YUutzLC 9ojvB8JGPManPBhnjs4aPIpliHTWcKcOncEkNgVmRQnTvOKWqQ7gRYJTGz3ylgqBSf36Y8 CGFUGi4AXB4C0a1y/DlgJOg+BBWnq3o= 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-686-KgZlg0-LOYey-cxs_dsX6g-1; Wed, 30 Jul 2025 09:12:22 -0400 X-MC-Unique: KgZlg0-LOYey-cxs_dsX6g-1 X-Mimecast-MFC-AGG-ID: KgZlg0-LOYey-cxs_dsX6g_1753881141 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (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 6C40819560BA; Wed, 30 Jul 2025 13:12:21 +0000 (UTC) Received: from gmonaco-thinkpadt14gen3.rmtit.com (unknown [10.44.33.26]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 0D29619560A2; Wed, 30 Jul 2025 13:12:16 +0000 (UTC) From: Gabriele Monaco To: linux-kernel@vger.kernel.org, Anna-Maria Behnsen , Frederic Weisbecker , Thomas Gleixner , Waiman Long Cc: Gabriele Monaco Subject: [PATCH v9 3/8] timers: Add the available mask in timer migration Date: Wed, 30 Jul 2025 15:11:53 +0200 Message-ID: <20250730131158.101668-4-gmonaco@redhat.com> In-Reply-To: <20250730131158.101668-1-gmonaco@redhat.com> References: <20250730131158.101668-1-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: 8bit X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 Keep track of the CPUs available for timer migration in a cpumask. This prepares the ground to generalise the concept of unavailable CPUs. Reviewed-by: Frederic Weisbecker Signed-off-by: Gabriele Monaco --- kernel/time/timer_migration.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/kernel/time/timer_migration.c b/kernel/time/timer_migration.c index 75fce6b8b642..57abdef7d0f8 100644 --- a/kernel/time/timer_migration.c +++ b/kernel/time/timer_migration.c @@ -422,6 +422,12 @@ static unsigned int tmigr_crossnode_level __read_mostly; static DEFINE_PER_CPU(struct tmigr_cpu, tmigr_cpu); +/* + * CPUs available for timer migration. + * Protected by cpuset_mutex (with cpus_read_lock held) or cpus_write_lock. + */ +static cpumask_var_t tmigr_available_cpumask; + #define TMIGR_NONE 0xFF #define BIT_CNT 8 @@ -1446,6 +1452,7 @@ static int tmigr_clear_cpu_available(unsigned int cpu) int migrator; u64 firstexp; + cpumask_clear_cpu(cpu, tmigr_available_cpumask); raw_spin_lock_irq(&tmc->lock); tmc->available = false; WRITE_ONCE(tmc->wakeup, KTIME_MAX); @@ -1459,7 +1466,7 @@ static int tmigr_clear_cpu_available(unsigned int cpu) raw_spin_unlock_irq(&tmc->lock); if (firstexp != KTIME_MAX) { - migrator = cpumask_any_but(cpu_online_mask, cpu); + migrator = cpumask_any(tmigr_available_cpumask); work_on_cpu(migrator, tmigr_trigger_active, NULL); } @@ -1474,6 +1481,7 @@ static int tmigr_set_cpu_available(unsigned int cpu) if (WARN_ON_ONCE(!tmc->tmgroup)) return -EINVAL; + cpumask_set_cpu(cpu, tmigr_available_cpumask); raw_spin_lock_irq(&tmc->lock); trace_tmigr_cpu_available(tmc); tmc->idle = timer_base_is_idle(); @@ -1811,6 +1819,11 @@ static int __init tmigr_init(void) if (ncpus == 1) return 0; + if (!zalloc_cpumask_var(&tmigr_available_cpumask, GFP_KERNEL)) { + ret = -ENOMEM; + goto err; + } + /* * Calculate the required hierarchy levels. Unfortunately there is no * reliable information available, unless all possible CPUs have been -- 2.50.1