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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 82286C43458 for ; Thu, 9 Jul 2026 06:10:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=oTpfQ49290vcsQPpkc1KAhPjJUa7iUBgEKlYPPzNJXU=; b=4GMUG+4+GCXuvZjPOOs1gj6pEU KTJg0TKQhhPa3FJI8/f1uurjfgnEqzUG0EdmMxErQAc5pziO61zLfGYhNG5Z00kglcB6IWpoOBRZS C9+IhZHUFFI7Ee9sDtoz6l2N+JriGRSKr+N3A0GVP3tRnI4sQKLqiJzZd0rsOHjEJHurXPyctCN0O 7HUEN3pitHywEN27hR2E0uSe92zWOPMXWJIo958wa5Y0MYNAq8InJrY6er4oISIsDuY0uzfQDuQAu R7b7nf5+wGAfLlq8SKTBqTPiW2zDbbWATpfbQnRWI9+O8CWrZXMwQkOQNW2qBVpBrBap3jsguhVEZ PNqCn4Lw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1whhxY-0000000179n-3CQO; Thu, 09 Jul 2026 06:10:08 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1whhxU-00000001797-1tlB for linux-nvme@lists.infradead.org; Thu, 09 Jul 2026 06:10:06 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 07E5D68BFE; Thu, 9 Jul 2026 08:10:00 +0200 (CEST) Date: Thu, 9 Jul 2026 08:09:59 +0200 From: Christoph Hellwig To: Yu Kuai Cc: Jens Axboe , Tejun Heo , Christoph Hellwig , Keith Busch , Sagi Grimberg , Alasdair Kergon , Benjamin Marzinski , Mike Snitzer , Mikulas Patocka , Dongsheng Yang , Zheng Gu , Coly Li , Kent Overstreet , Josef Bacik , Yu Kuai , Nilay Shroff , linux-block@vger.kernel.org, cgroups@vger.kernel.org, linux-nvme@lists.infradead.org, dm-devel@lists.linux.dev, linux-bcache@vger.kernel.org Subject: Re: [RFC PATCH v1 00/17] blk-cgroup: protect blkgs with blkcg_mutex Message-ID: <20260709060959.GA16504@lst.de> References: <20260704195124.1375075-1-yukuai@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260704195124.1375075-1-yukuai@kernel.org> User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260708_231004_640648_2EBFBEDB X-CRM114-Status: GOOD ( 14.69 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Sun, Jul 05, 2026 at 03:51:07AM +0800, Yu Kuai wrote: > From: Yu Kuai > > This RFC moves queue-local blkg topology synchronization from > q->queue_lock to q->blkcg_mutex. > > q->queue_lock is a hot block-layer spinlock used by request queue runtime > paths, I don't think it is hot any more. If it is in one of your workloads we have a deep problem somewhere. That being said, futher removing uses of his old catch-all lock is always good, hopefully we can eventually remove it entirely. So this series looks great to me conceptually, but I'm unfortunately not a very qualified reviewer for the blk-cgroup code.