From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 058A92E6CD9 for ; Fri, 26 Dec 2025 02:24:59 +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=1766715902; cv=none; b=Rs5WAgfn4TQ6fclmJ6DWQUF3mOfMkJYHE7X0YgkPbDTzc6WhY7jHwTyL1ZAOe2ysImR+OcK1JsYDojKcNZ56d5bWV2xmqckFwmWroNVMP4T3prJCsAFsnQMyPPHMAEEl2t9a+STT5r4WONIQwtfR5TyMs+GDMWGZPCvn6/TIqfI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766715902; c=relaxed/simple; bh=vBsV97FFWt6taOOfI5IvjUETKhYJ9bzwqpworgVKu8o=; h=From:Message-ID:Date:MIME-Version:Subject:To:Cc:References: In-Reply-To:Content-Type; b=DD9WMvCMjIqJz+7MTdgag3chUkE14pOyAvLv3xjwXduV1US0onc9sILQGnFUpmjlMzYLz/oe/DQoVuEHgSohyxp0tU3lCanUgKU2m7o4/VpKLRAU+g/WIPCwg3gjIZOBJtrVCUrL8MJaAUWagzAsdX4ziAs+kfQbAN82q+z0HL0= 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=hOwfFZ71; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b=D+T4u0/Q; 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="hOwfFZ71"; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b="D+T4u0/Q" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1766715899; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=0Qsz5WPFD/uExCJQBnyZrl3TgkdgAhutxKnz59++5sE=; b=hOwfFZ710VPjketZu6BcT4FTzJihP8HWqg/bEK12ffUbnuOtlDn7F61S+drIcBvfayJQiO uPy0yhHcM91k1GV2F+M763QrXGRwYmf+LWEV70nvqdRGZ8sqHgZDdM9/DyyMUzRO0B+5+j Ulw5E/AE8OgX604RaBBQKKgGs5fV6ec= Received: from mail-pg1-f197.google.com (mail-pg1-f197.google.com [209.85.215.197]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-211-WHYU_QuYNhiQha2k5dCc9g-1; Thu, 25 Dec 2025 21:24:57 -0500 X-MC-Unique: WHYU_QuYNhiQha2k5dCc9g-1 X-Mimecast-MFC-AGG-ID: WHYU_QuYNhiQha2k5dCc9g_1766715897 Received: by mail-pg1-f197.google.com with SMTP id 41be03b00d2f7-ba4c6ac8406so5699903a12.0 for ; Thu, 25 Dec 2025 18:24:57 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=google; t=1766715897; x=1767320697; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:content-language:references :cc:to:subject:user-agent:mime-version:date:message-id:from:from:to :cc:subject:date:message-id:reply-to; bh=0Qsz5WPFD/uExCJQBnyZrl3TgkdgAhutxKnz59++5sE=; b=D+T4u0/QjBdxWPDhpxoAygtibZkXthUyHqYlfsOr8ZRLzEMMs9MCv+FeMoHM+koWXG ojVEXXGiuWq5LFvgXXlpTu2xdnXBmqaSfXbhvgeqkn+q3BFbIMQKpU9WxeJ3aDilfjc2 8dix5/fTrgpX87HKuTOrhvexEXbAx9xSQ8kI/x3aLjOjm/zjcMeMJcazOmQ7/5qVQLqY 09mU0TQkTLVKEEytMSkvhYQueHM2iK7jGI/OK0basFrDm7fWwFQ+nq+pDf1nP+yoLZOG OJlz9mYNkBIGrBqdVPHMTNeE6IPLm30zv6LV7Pp3N1W68waxdELK/fuKVbm5LrQoNlPv BqIg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1766715897; x=1767320697; h=content-transfer-encoding:in-reply-to:content-language:references :cc:to:subject:user-agent:mime-version:date:message-id:from:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=0Qsz5WPFD/uExCJQBnyZrl3TgkdgAhutxKnz59++5sE=; b=niRdpNjzbdCGf3E1fv4R8jnt4Ucg205pEy0k/6sh2CQKxERsJCNrhA3aQDE0r+IA46 oFkIK0kNaWTW/1p4GdKvcVvva4IYBfoPlt0B8AjqU+Wrr76gmaoeAh/XijJdKReIYxW5 iAcriSUIdSdR3u7eUlrUQg5lW16VUp5KdwxIG8+UsiGK4jq5w7Pt4yJiRBOeUCkF3D/X N3pt9VDhTUofzXzpLg4cQcmD+d5hmsuTVsCKsDrUwwT0/gWd2Yxc/qjuSfstshlwpPb2 dLMCKvnf99/XNj0mPENYaBVs4PG17Lq3eLeEDUO5jVWz+1Qp+gAhYqfPx3Epwtic0+KL +m/g== X-Forwarded-Encrypted: i=1; AJvYcCUrnt9VjykAggkBoWmmyvTaFKMZoPIPUXntS0TLBxF0JmKtxreOk+d4dQQLSd5983iqkBguO5wk6GQdxw==@vger.kernel.org X-Gm-Message-State: AOJu0Yz8fxk1i8P1ZuqGpW8Y+2UKjm76njBDrXY+3Oll+zdDRl5UOPFo 7Ky0n93uMZOHxKPAax/NtwPDyIpzJ32t9z0Ut/UzwA2I6FQEVNzKxJfd5R6l1o9pzo3jl7hM69t lSwChEW8bNlvASD71YLFMotAcD/fOTYmay5d+q/x71yHCnPcF1HF0mTMVO/bvS4cu X-Gm-Gg: AY/fxX7IO5d5sIXF0HW+EMjrYI1/hS4xt+w04Wkbm4p/t/j81IdNFeG/8iRRVWSYap/ ShD4dgtbh32puKluc72Mr4lxIjzO7k1py6OpP9P2itnaGsajjIWctYKpVZoSmz1PY4i5bPtp5B5 DZlhW7Riivh6EnRY49HKIPkSrx2xuwyQu1qy7yW8qUcBhNMpgIhyhF1k735tfksWsE/QoIhkVwT FgUFSUL/p0IFL3HPIVcHXxFAWI3IOj1XLPbNNcbUxnw9XbboUGUMqRDeWEAGk6LrS10tb/LQRik i0l3oWix8Kza5mg/znTFn2rMUepZh0mLJaaYTKBc3TNB7fOJ9BlXhyHIXX++KVNF+zXFEXEQOfq P8l252mDP3LoPxgPRDnq7SheJ8HBuRqWiKBPm66LvMX+/7i6VEXTYxde5 X-Received: by 2002:a05:7301:7d16:b0:2ae:526a:961d with SMTP id 5a478bee46e88-2b05ec8642fmr15215232eec.40.1766715896412; Thu, 25 Dec 2025 18:24:56 -0800 (PST) X-Google-Smtp-Source: AGHT+IGXdA8ClkjU6K261gUhCEsY/UDJEEfrrLSdJplFZD7gmyleR6jxqLs3c/WeMtHejh420lmUqA== X-Received: by 2002:a05:7301:7d16:b0:2ae:526a:961d with SMTP id 5a478bee46e88-2b05ec8642fmr15215216eec.40.1766715895871; Thu, 25 Dec 2025 18:24:55 -0800 (PST) Received: from ?IPV6:2601:600:947f:f020:85dc:d2b2:c5ee:e3c4? ([2601:600:947f:f020:85dc:d2b2:c5ee:e3c4]) by smtp.gmail.com with ESMTPSA id 5a478bee46e88-2b05ffad66fsm49761798eec.4.2025.12.25.18.24.43 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 25 Dec 2025 18:24:55 -0800 (PST) From: Waiman Long X-Google-Original-From: Waiman Long Message-ID: <17aadc7e-7dd6-4335-a748-e66f0239df85@redhat.com> Date: Thu, 25 Dec 2025 21:24:41 -0500 Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 14/33] cpuset: Update HK_TYPE_DOMAIN cpumask from cpuset To: Frederic Weisbecker , LKML Cc: =?UTF-8?Q?Michal_Koutn=C3=BD?= , Andrew Morton , Bjorn Helgaas , Catalin Marinas , Chen Ridong , Danilo Krummrich , "David S . Miller" , Eric Dumazet , Gabriele Monaco , Greg Kroah-Hartman , Ingo Molnar , Jakub Kicinski , Jens Axboe , Johannes Weiner , Lai Jiangshan , Marco Crivellari , Michal Hocko , Muchun Song , Paolo Abeni , Peter Zijlstra , Phil Auld , "Rafael J . Wysocki" , Roman Gushchin , Shakeel Butt , Simon Horman , Tejun Heo , Thomas Gleixner , Vlastimil Babka , Will Deacon , cgroups@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-block@vger.kernel.org, linux-mm@kvack.org, linux-pci@vger.kernel.org, netdev@vger.kernel.org References: <20251224134520.33231-1-frederic@kernel.org> <20251224134520.33231-15-frederic@kernel.org> Content-Language: en-US In-Reply-To: <20251224134520.33231-15-frederic@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 12/24/25 8:45 AM, Frederic Weisbecker wrote: > Until now, HK_TYPE_DOMAIN used to only include boot defined isolated > CPUs passed through isolcpus= boot option. Users interested in also > knowing the runtime defined isolated CPUs through cpuset must use > different APIs: cpuset_cpu_is_isolated(), cpu_is_isolated(), etc... > > There are many drawbacks to that approach: > > 1) Most interested subsystems want to know about all isolated CPUs, not > just those defined on boot time. > > 2) cpuset_cpu_is_isolated() / cpu_is_isolated() are not synchronized with > concurrent cpuset changes. > > 3) Further cpuset modifications are not propagated to subsystems > > Solve 1) and 2) and centralize all isolated CPUs within the > HK_TYPE_DOMAIN housekeeping cpumask. > > Subsystems can rely on RCU to synchronize against concurrent changes. > > The propagation mentioned in 3) will be handled in further patches. > > Signed-off-by: Frederic Weisbecker > --- > include/linux/sched/isolation.h | 7 +++ > kernel/cgroup/cpuset.c | 3 ++ > kernel/sched/isolation.c | 76 ++++++++++++++++++++++++++++++--- > kernel/sched/sched.h | 1 + > 4 files changed, 81 insertions(+), 6 deletions(-) > > diff --git a/include/linux/sched/isolation.h b/include/linux/sched/isolation.h > index 109a2149e21a..6842a1ba4d13 100644 > --- a/include/linux/sched/isolation.h > +++ b/include/linux/sched/isolation.h > @@ -9,6 +9,11 @@ > enum hk_type { > /* Revert of boot-time isolcpus= argument */ > HK_TYPE_DOMAIN_BOOT, > + /* > + * Same as HK_TYPE_DOMAIN_BOOT but also includes the > + * revert of cpuset isolated partitions. As such it > + * is always a subset of HK_TYPE_DOMAIN_BOOT. > + */ > HK_TYPE_DOMAIN, > /* Revert of boot-time isolcpus=managed_irq argument */ > HK_TYPE_MANAGED_IRQ, > @@ -35,6 +40,7 @@ extern const struct cpumask *housekeeping_cpumask(enum hk_type type); > extern bool housekeeping_enabled(enum hk_type type); > extern void housekeeping_affine(struct task_struct *t, enum hk_type type); > extern bool housekeeping_test_cpu(int cpu, enum hk_type type); > +extern int housekeeping_update(struct cpumask *isol_mask, enum hk_type type); > extern void __init housekeeping_init(void); > > #else > @@ -62,6 +68,7 @@ static inline bool housekeeping_test_cpu(int cpu, enum hk_type type) > return true; > } > > +static inline int housekeeping_update(struct cpumask *isol_mask, enum hk_type type) { return 0; } > static inline void housekeeping_init(void) { } > #endif /* CONFIG_CPU_ISOLATION */ > > diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c > index 5e2e3514c22e..e13e32491ebf 100644 > --- a/kernel/cgroup/cpuset.c > +++ b/kernel/cgroup/cpuset.c > @@ -1490,6 +1490,9 @@ static void update_isolation_cpumasks(void) > ret = tmigr_isolated_exclude_cpumask(isolated_cpus); > WARN_ON_ONCE(ret < 0); > > + ret = housekeeping_update(isolated_cpus, HK_TYPE_DOMAIN); > + WARN_ON_ONCE(ret < 0); > + > isolated_cpus_updating = false; > } > > diff --git a/kernel/sched/isolation.c b/kernel/sched/isolation.c > index 83be49ec2b06..a124f1119f2e 100644 > --- a/kernel/sched/isolation.c > +++ b/kernel/sched/isolation.c > @@ -29,18 +29,48 @@ static struct housekeeping housekeeping; > > bool housekeeping_enabled(enum hk_type type) > { > - return !!(housekeeping.flags & BIT(type)); > + return !!(READ_ONCE(housekeeping.flags) & BIT(type)); > } > EXPORT_SYMBOL_GPL(housekeeping_enabled); > > +static bool housekeeping_dereference_check(enum hk_type type) > +{ > + if (IS_ENABLED(CONFIG_LOCKDEP) && type == HK_TYPE_DOMAIN) { To be more correct, we should use IS_ENABLED(CONFIG_PROVE_LOCKING) as this is the real kconfig that enables most of the lockdep checking. PROVE_LOCKING selects LOCKDEP but not vice versa. So for some weird configs that set LOCKDEP but not PROVE_LOCKING, it can cause compilation problem. Other than that, the rest looks good to me. Cheers, Longman