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 43426C44501 for ; Thu, 9 Jul 2026 06:13:58 +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=uMYq9cG/rxD4S9M4Bz3xT+UHw1tldDaTR6qW8eCUA00=; b=n67jCr0JH6iDME/akwwp6p38oA 7TXuhGftxhJgIqmlF2OwEG1jPP0qvUp1V1yLypb+oy5SP69y/5X/bBWZX7SWICNCtMpqH18Qsp/tf IxLv4YrKRipNFOBAUx5KTJcb7LFD1EEg/YHxfh6y2v0B0SUSq73AqyE7g4pkUnD7BhUfdAdzAbXA5 FOIPsK0KyETXt7uf/KWcbtvWGKep00ESz2KTv9WXZWCed4n3ZC6O8UCJWu9udP4BYsRZ0eR8ELT8d d5G0tU5J/2conRJpwMFM7s1DROsODzip160TL5JWd72k1G4lSOR1nk9f5+JuUtRlNxuGO8QSx7edh 6CQSQSxg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1whi1F-000000017po-481G; Thu, 09 Jul 2026 06:13:57 +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 1whi19-000000017oi-40M9 for linux-nvme@lists.infradead.org; Thu, 09 Jul 2026 06:13:56 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 5B41F68CFE; Thu, 9 Jul 2026 08:13:49 +0200 (CEST) Date: Thu, 9 Jul 2026 08:13:49 +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 06/17] blk-cgroup: support non-blocking bio association Message-ID: <20260709061349.GD16504@lst.de> References: <20260704195124.1375075-1-yukuai@kernel.org> <20260704195124.1375075-7-yukuai@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260704195124.1375075-7-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_231352_139848_218A9AEA X-CRM114-Status: GOOD ( 12.98 ) 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 03:51:13AM +0800, Yu Kuai wrote: > From: Yu Kuai > > Allow bio association helpers to be called from non-blocking paths by > returning whether the association succeeded and by taking a nowait argument. > The normal callers pass nowait=false and keep the existing behavior of > creating missing blkgs. > > For nowait=true, the helper only succeeds when the needed blkg already > exists. This lets callers set or clone a bio's bdev without entering the > sleepable missing-blkg creation path. I think this is not needed once we kill nonblocking bio allocations, but if not please have a clearly visible separate API for the non-blocking version.