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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 8A03AC55822 for ; Tue, 4 Aug 2026 15:47:33 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 47B346B0109; Tue, 4 Aug 2026 11:47:32 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 453B66B010A; Tue, 4 Aug 2026 11:47:32 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 36A1F6B010B; Tue, 4 Aug 2026 11:47:32 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 14AD96B0109 for ; Tue, 4 Aug 2026 11:47:32 -0400 (EDT) Received: from smtpin29.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 9F7EEA023A for ; Tue, 4 Aug 2026 15:47:31 +0000 (UTC) X-FDA: 85064016702.29.84C619B Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by imf11.hostedemail.com (Postfix) with ESMTP id CEB7B40008 for ; Tue, 4 Aug 2026 15:47:29 +0000 (UTC) Authentication-Results: imf11.hostedemail.com; dkim=none; spf=pass (imf11.hostedemail.com: domain of hch@lst.de designates 213.95.11.211 as permitted sender) smtp.mailfrom=hch@lst.de; dmarc=pass (policy=none) header.from=lst.de ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1785858450; h=from:from:sender: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: in-reply-to:in-reply-to:references:references; bh=3INYlQKobLh4mMVUFvPghDpGiNw6y0KRfCXHtoDWGyE=; b=GvujAkDNJDwmhV6ZqejsGqg72PRjQYN1L4zmR2u7e/7yjvtZSEZspBBLLD9by0rzMkod3a 3H+iQ6Etb7LXR8FN8ga7uo7rQyANI/1HJijrQWS0OKU/moEL1VwNnBBLdH6JQzCVL299Lj U83TYDlkBYvpy5/AKJmxLx2cbprBew4= ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1785858450; b=EHX3hC1CYhV+6OoX2X/GG0pbgOaPONzwmdrHwc+8OQHe1Hx31Tro8q5rHhNy3pbqopItX7 Uw7WaiyRGy+77AduAsBGOJNAbqFcNKSDPbwHUfv5cYKLqX1nr1WPSQvWt+kYjSAoPDXEwZ cSnj4l+arJRk8lg6HgumwxNeoSnREcY= ARC-Authentication-Results: i=1; imf11.hostedemail.com; dkim=none; spf=pass (imf11.hostedemail.com: domain of hch@lst.de designates 213.95.11.211 as permitted sender) smtp.mailfrom=hch@lst.de; dmarc=pass (policy=none) header.from=lst.de Received: by verein.lst.de (Postfix, from userid 2407) id 5789C6732A; Tue, 4 Aug 2026 17:47:22 +0200 (CEST) Date: Tue, 4 Aug 2026 17:47:21 +0200 From: Christoph Hellwig To: yu kuai Cc: Christoph Hellwig , Tao Cui , Yu Kuai , Jens Axboe , Tejun Heo , Johannes Weiner , Michal =?iso-8859-1?Q?Koutn=FD?= , Jonathan Corbet , Josef Bacik , Coly Li , Kent Overstreet , Alasdair Kergon , Mike Snitzer , Mikulas Patocka , Benjamin Marzinski , Song Liu , Dan Williams , Vishal Verma , Dave Jiang , Alison Schofield , Pankaj Gupta , Andreas Gruenbacher , Matthew Wilcox , Jan Kara , Andrew Morton , Chris Li , Kairui Song , Nilay Shroff , cgroups@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, linux-bcache@vger.kernel.org, dm-devel@lists.linux.dev, linux-raid@vger.kernel.org, nvdimm@lists.linux.dev, virtualization@lists.linux.dev, gfs2@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [RFC PATCH v1 2/3] blk-cgroup: store blkcg in bio instead of blkg Message-ID: <20260804154721.GA11379@lst.de> References: <20260804065313.2092022-1-yukuai@kernel.org> <20260804065313.2092022-3-yukuai@kernel.org> <20260804133208.GB8078@lst.de> <0fc5dd22-7a8d-43f0-8555-d2ca966efff6@fygo.io> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <0fc5dd22-7a8d-43f0-8555-d2ca966efff6@fygo.io> User-Agent: Mutt/1.5.17 (2007-11-01) X-Rspamd-Queue-Id: CEB7B40008 X-Rspamd-Server: rspam10 X-Rspam-User: X-Stat-Signature: sbbiope64rh3zqqi98yuyob37bgtdcyi X-HE-Tag: 1785858449-737076 X-HE-Meta: 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 RxtD/kZ/ 15UDZdcuqLnilfVkQynz2OOV/PXlWKVHr3IQ/sLV5/buePpFrNqY1Z8evKrz85FJl4gy6rz9iM9jLv+NgRXlyKXNkcYdf4A9edWEcto7yfUaZaV6CO1nF4WbuDXbfl1yVG3Sip5lFQuHfi+Mm09bqgGNoW7U/rbD+6JX+ZfF5piRSEhlC/aLZnucJGouRrAQLsila Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Tue, Aug 04, 2026 at 11:30:55PM +0800, yu kuai wrote: > The problem here is that remove a cgroup can also remove the blkg from radix tree, > even through it still has active refcounts. I think this can be fixed by checking > the cgroup online_pin first, if it's zero, we can search the blkg from the > request_queue blkg list, where blkg will not be removed until blkg_free_workfn(). > What's better, if we can convert the blkg list to hash table with key as blk-cgroup, > it will be much better as we can lookup from this table instead of blkcg radix tree. Yes, I think you can really easily do that with the rhashtable.