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 X-Spam-Level: X-Spam-Status: No, score=-6.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 15E96C4363A for ; Mon, 5 Oct 2020 12:48:44 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 52BB2206A1 for ; Mon, 5 Oct 2020 12:48:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="KoYwPl+q" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 52BB2206A1 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=VQ+zPTJX1ViUa0JLY6PqyfggwKX1R8ajcb9gsOF9zck=; b=KoYwPl+q3w6HTb3YoPBs9D2og vTPdJFlixSnRNM4Nap4mVQHLlzrPvg8CSfZlAeUaseQgJmq7l1uawqRc0733yTUGDRH2REEKesiss sU8TLftLWSHaAE9aggOrZEElJrnoa7hFgJNt2cQtqtP4q8cyGlTgx5W82hFXpgp8NpGVtt5I5p42K 0KhJI8LFYuGle46PfPndoOH3u4RQGqWbKDwVo7frSGUCMFmNn6rgK2v/LZWJ/dMgqmeX1A2wYs7Am 3jKDjJEdWjBNMuOuw7udZQesPQzZRonYaUwN1bTZzC7dOQq2k5BQrogCH0L3B1/F/IwSXXs1tm/Bg haExzCBRw==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kPPuy-0004B0-Qf; Mon, 05 Oct 2020 12:48:40 +0000 Received: from verein.lst.de ([213.95.11.211]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kPPuv-0004A6-SO for linux-nvme@lists.infradead.org; Mon, 05 Oct 2020 12:48:38 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id CB19267373; Mon, 5 Oct 2020 14:48:35 +0200 (CEST) Date: Mon, 5 Oct 2020 14:48:35 +0200 From: Christoph Hellwig To: Chaitanya Kulkarni Subject: Re: [PATCH V2 2/2] nvme-loop: use xarray for loop port tracking Message-ID: <20201005124835.GB518@lst.de> References: <20200930045557.53669-1-chaitanya.kulkarni@wdc.com> <20200930045557.53669-3-chaitanya.kulkarni@wdc.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200930045557.53669-3-chaitanya.kulkarni@wdc.com> User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201005_084838_041630_98DD1A72 X-CRM114-Status: UNSURE ( 9.97 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: hch@lst.de, linux-nvme@lists.infradead.org, sagi@grimberg.me Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org > + unsigned long idx; > > - mutex_lock(&nvme_loop_ports_mutex); > - list_for_each_entry(p, &nvme_loop_ports, entry) { > + rcu_read_lock(); > + xa_for_each(&nvme_loop_ports, idx, p) { Why is the rcu_read_lock()? We'd need a synchronize_rcu on the port disable side. But the manual mutex_locking seems more sensible here anyway. > + xa_init(&nvme_loop_ports); I don't think this is needed. _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme