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 B0FF616EB5E for ; Thu, 11 Jul 2024 19:13:23 +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=1720725205; cv=none; b=SxFsedHgaHTRqdhbzWrFaU0RN7sUyXDurAbpij5av1kUuoLbHDl5/J89wr66l8rLjYrmW7nKEdnzVYOc4ADU1jBKAhGINBCgvaOR1hwX+INFWPqqdyVVFi89tgGrgFNdYxJnSmDMCsrDLyD1iEgGVmMyV6QzxKe6PPAwUYlny58= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720725205; c=relaxed/simple; bh=IPwjW9zXDZj0GjSWo+ya1iX9LOavMvZQSGNliR7UjEE=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=W4EDNF2FY0wQJz3Jg7woo1Sj8xGQ+XDHmHjYCf9HPNHAH2JjJHXx/BNKt8/6U3AxD8/d/RwVaAR/HJEPUGEy8ZnhVkuqPD9nkjaryeAORzbMDaDoG2peWlGyFS9Pyjqx72mF/sz66VEEli/7Bhr9pVzzSmia5N8X3BSw0BhjD3c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none 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=OPZeoeMp; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none 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="OPZeoeMp" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1720725202; 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=J1JVyAyiTtlCI1FBawwo7Uxh6OheB0hyVqTCLlGomRo=; b=OPZeoeMp2/xCQMuBR7Y0oGmCZlYJji1N0csZNm44+EkeIHIL1dmrVcYlN0dB9ldV0RAY2r ojWG5cBdjD4pgQtzFU6vH7T4xVmVbJfv5d+E1fksQjbLh+0kzXLhJyoA8Cj4WYXoEqnsOz XF+DTAg25DhpRa9QgonEX9YVFdPjVco= Received: from mx-prod-mc-04.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-335-5kLsRJz8M3iw1AZ5-zhIVg-1; Thu, 11 Jul 2024 15:13:17 -0400 X-MC-Unique: 5kLsRJz8M3iw1AZ5-zhIVg-1 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (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-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 306051955F66; Thu, 11 Jul 2024 19:13:15 +0000 (UTC) Received: from [10.22.64.119] (unknown [10.22.64.119]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 38CF61955F40; Thu, 11 Jul 2024 19:13:13 +0000 (UTC) Message-ID: Date: Thu, 11 Jul 2024 15:13:12 -0400 Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 1/2] cgroup: Show # of subsystem CSSes in cgroup.stat To: Tejun Heo Cc: Johannes Weiner , Zefan Li , Jonathan Corbet , cgroups@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, Kamalesh Babulal , Roman Gushchin References: <20240710182353.2312025-1-longman@redhat.com> <20240711134927.GB456706@cmpxchg.org> <4e1078d6-6970-4eea-8f73-56a3815794b5@redhat.com> <76e70789-986a-44c2-bfdc-d636f425e5ae@redhat.com> Content-Language: en-US From: Waiman Long In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 On 7/11/24 14:59, Tejun Heo wrote: > On Thu, Jul 11, 2024 at 02:51:38PM -0400, Waiman Long wrote: >> On 7/11/24 14:44, Tejun Heo wrote: >>> Hello, >>> >>> On Thu, Jul 11, 2024 at 01:39:38PM -0400, Waiman Long wrote: >>>> On 7/11/24 13:18, Tejun Heo wrote: >>> ... >>>> Currently, I use the for_each_css() macro for iteration. If you mean >>>> displaying all the possible cgroup subsystems even if they are not enabled >>>> for the current cgroup, I will have to manually do the iteration. >>> Just wrapping it with for_each_subsys() should do, no? for_each_css() won't >>> iterate anything if css doesn't exist for the cgroup. >> OK, I wasn't sure if you were asking to list all the possible cgroup v2 >> cgroup subsystems even if they weren't enabled in the current cgroup. >> Apparently, that is the case. I prefer it that way too. > Yeah, I think listing all is better. If the list corresponded directly to > cgroup.controllers, it may make sense to only show enabled ones but we can > have dying ones and implicitly enabled memory and so on, so I think it'd be > cleaner to just list them all. That will means cgroup subsystems that are seldomly used like rdma, misc or even hugetlb will always be shown in all the cgroup.stat output. I actually prefer just showing those that are enabled. As for dying memory cgroups, they will only be shown in its online ancestors. We currently don't know how many level down are each of the dying ones. Cheers, Longman