From mboxrd@z Thu Jan 1 00:00:00 1970 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 BB0CFE7E657 for ; Tue, 26 Sep 2023 18:25:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229809AbjIZSZb (ORCPT ); Tue, 26 Sep 2023 14:25:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41178 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235475AbjIZSZ2 (ORCPT ); Tue, 26 Sep 2023 14:25:28 -0400 Received: from mail-pf1-x429.google.com (mail-pf1-x429.google.com [IPv6:2607:f8b0:4864:20::429]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B0C59136; Tue, 26 Sep 2023 11:25:21 -0700 (PDT) Received: by mail-pf1-x429.google.com with SMTP id d2e1a72fcca58-690d9cda925so7314401b3a.3; Tue, 26 Sep 2023 11:25:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1695752721; x=1696357521; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:from:to:cc:subject:date:message-id :reply-to; bh=mL/CHvcHgJZFxYJYLpsg7SBW9N36wXwuTr+5AxMKYEM=; b=E2ybVHOyKLtxteKkfHFCaEm8gRch9Pcx2ISqkNoq7pKtr6YRNebHLvtW2TXYfI+S/T Loef4K8pn2F/umiQEIKFbsCxfCs/m+B7/nI3UuEpu6xJvwRkTqw5w4cLmd0OHL1okRPi VUVi0OWVygIRga+Nuv5SqEQZlL8y0e9CbAD959hUWppZyphBQawOSp2iXGR1CYswq9ku oHl8NfgH1GMb8fzhbXi73IFV3xHpdDKEFHh5h7Q8Rjpxa2XvDCgYa3M5vGndjfxWd/0v ElUt9lr+gXLeIPNcwI6agw0vR18mDSfWruM753eI9wxxH6kxw3Gf9EMqyeYFuW+dexid Prcg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1695752721; x=1696357521; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=mL/CHvcHgJZFxYJYLpsg7SBW9N36wXwuTr+5AxMKYEM=; b=G7p+4+IhraYECOBS1vlHwn72irjNfZiCg34ztbjuIERnOrQDnCPR5st8+SFyQgSBbj M1nsN0MLSYPnTtRyo9ga8bd31Yf2mMZm/1tT1Ra9umBL1nq7Vw1hoPelkQ9kosuSICgG 7RkRoj0kc8MRaUMjlzhMr1buocyaXG8eNLqh2Ma7fqAbv+GExGRViRRxjNEoqNeJEhq2 EAFr3lZ7r2wq7SnugkOysGz7RI1s04KQgtagb94XnmdHlhDsTGQgaeOlVXyT2eZL+O34 A+ZGs/5EamEK13IEx6614jRfz6P3zLMjcsOCXAFCyempxVmDjFmNBcZ2JS1wCiVrzMxb tIMQ== X-Gm-Message-State: AOJu0YzA8xHn6LxeGsrGDFlrC8aw5SJ8HtE1kiWwkxjoEyrKexjoEaEP BcPARptORFfNfVESYVdO+rknKhUlaVDIJA== X-Google-Smtp-Source: AGHT+IGwqu5jXLn7iFSLyPz8LErf6nFqrlKwCsOwTqnm3SpYPcIQZ40TIJbwamFkfV/7oSxlMmB3iw== X-Received: by 2002:a05:6a00:1249:b0:692:b6e8:ce88 with SMTP id u9-20020a056a00124900b00692b6e8ce88mr8328168pfi.17.1695752721060; Tue, 26 Sep 2023 11:25:21 -0700 (PDT) Received: from localhost ([2620:10d:c090:400::4:dfcd]) by smtp.gmail.com with ESMTPSA id fk1-20020a056a003a8100b00682868714fdsm10674491pfb.95.2023.09.26.11.25.20 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 26 Sep 2023 11:25:20 -0700 (PDT) Sender: Tejun Heo Date: Tue, 26 Sep 2023 08:25:19 -1000 From: Tejun Heo To: Yafang Shao Cc: ast@kernel.org, daniel@iogearbox.net, john.fastabend@gmail.com, andrii@kernel.org, martin.lau@linux.dev, song@kernel.org, yonghong.song@linux.dev, kpsingh@kernel.org, sdf@google.com, haoluo@google.com, jolsa@kernel.org, lizefan.x@bytedance.com, hannes@cmpxchg.org, yosryahmed@google.com, mkoutny@suse.com, cgroups@vger.kernel.org, bpf@vger.kernel.org Subject: Re: [RFC PATCH bpf-next 0/8] bpf, cgroup: Add bpf support for cgroup controller Message-ID: References: <20230922112846.4265-1-laoar.shao@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: cgroups@vger.kernel.org Hello, On Tue, Sep 26, 2023 at 11:01:08AM +0800, Yafang Shao wrote: > Thanks for your suggestion. I will think about it. > BTW, I can't find the hierarchy ID of systemd (/sys/fs/cgroup/systemd) > in /proc/cgroups. Is this intentional as part of the design, or might > it be possible that we overlooked it? > In the userspace, where can we find the hierarchy ID of a named hierarchy? Yeah, /proc/cgroups only prints the hierarchies which have controllers attached to them. The file is pretty sad in general. However, /proc/PID/cgroup prints all existing hierarchies along with their IDs and identifiers (controllers or names). Hopefully, that should be enough? Thanks. -- tejun