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=-0.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 7B9A9C432C3 for ; Sat, 30 Nov 2019 06:04:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4FD3D2082E for ; Sat, 30 Nov 2019 06:04:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="itp6mkD1" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726497AbfK3GD7 (ORCPT ); Sat, 30 Nov 2019 01:03:59 -0500 Received: from mail-pl1-f170.google.com ([209.85.214.170]:36296 "EHLO mail-pl1-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725298AbfK3GD6 (ORCPT ); Sat, 30 Nov 2019 01:03:58 -0500 Received: by mail-pl1-f170.google.com with SMTP id k20so1355207pls.3 for ; Fri, 29 Nov 2019 22:03:57 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=Ec0nFTYvaYnyk/8sDq3u071ZfoJJIOH3vX8mQ8EjYTU=; b=itp6mkD1SRHUUM3dzkGUrTGZzeeghUrRVdwLIS+sv8ByFdjtSolJb+2ptNl3ZpxOaa qQ9F5atiSWznAvMIl3Hw3JceCA1xSO1eu6s403schCBBQ0CT5cNxiDdUmnQDgTFGWUVs M578TrlCLWiNC5vIDgGZ/1cG6hw02MAiNfAufnYJIO556KE5x4xNLf14iyBNqlB5wNF7 PgGRDhnPLaWul1v9YnWxVL7RuflGc3f1raBaQZjRScfzFGB5GnlbFjJYLNpf2ZrNdx2l +2fJgWEXIjPDkLB151Y3BMALbCdyeqfadyCZXQ/UdJe8ShKGjCdOyyucDqwtFFkIgx2C fx4w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=Ec0nFTYvaYnyk/8sDq3u071ZfoJJIOH3vX8mQ8EjYTU=; b=RgovCVtZoLMrJ1C1LuVSTJftsmSUuVkNs+WxYiMy1NmPWV8l1bBsGWbvlpGGiOUj6H cH4RAnE7b/tZ1Qc+mKFXJg+zjjAZ0+Q0756QHNVOyYHzbTWTmUHQ4p/m0LeesPw8Il/C OJ4dDKvCnZffwbt0n2fVgY9yLpetdNbF2p1LEuGY3A9+ySeGdE1V9wtw88gktikMwIbW Altz1cgdF0K8dZwMRFGs84SYCVTdVqc+80AC++h+/as5+C560M7p0R8GaTn2sM0dFPdH iIfXs1ZoZsVFJBRfWhTwSt/LG5oN7BBouDDCj2RptpzOopXw7gk1zvRIFni8ChBjPMnW I34A== X-Gm-Message-State: APjAAAWSQMCU7wP2v560X87/Gn6QFWtI7uGw7EZ2npyszC+w7/0D7LGM 1vkpTG4rSum9jEgWGSBEOe1Pb6pDVmpR/HwqEFI= X-Google-Smtp-Source: APXvYqx2nNvpp3u1ft6zY2DBl10NREssYrBkm84da2QSyHGCXrj7U45ZHl6Wj4R2eUiIL9Vykmwj2WerfPtLQkzMYao= X-Received: by 2002:a17:902:9a03:: with SMTP id v3mr17750785plp.61.1575093836764; Fri, 29 Nov 2019 22:03:56 -0800 (PST) MIME-Version: 1.0 References: <20191129004855.18506-1-xiyou.wangcong@gmail.com> <20191129004855.18506-4-xiyou.wangcong@gmail.com> In-Reply-To: From: Cong Wang Date: Fri, 29 Nov 2019 22:03:45 -0800 Message-ID: Subject: Re: [Patch v2 3/3] iommu: avoid taking iova_rbtree_lock twice To: John Garry Cc: iommu@lists.linux-foundation.org, LKML Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Nov 29, 2019 at 5:34 AM John Garry wrote: > > On 29/11/2019 00:48, Cong Wang wrote: > > Both find_iova() and __free_iova() take iova_rbtree_lock, > > there is no reason to take and release it twice inside > > free_iova(). > > > > Fold them into the critical section by calling the unlock > > versions instead. > > Since generally the iova would be non-NULL, this seems a reasonable > change (which could be mentioned in the commit log) I think it is too obvious to mention it. There are many things we can mention but we should only mention what's necessary, right? Thanks. 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charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" On Fri, Nov 29, 2019 at 5:34 AM John Garry wrote: > > On 29/11/2019 00:48, Cong Wang wrote: > > Both find_iova() and __free_iova() take iova_rbtree_lock, > > there is no reason to take and release it twice inside > > free_iova(). > > > > Fold them into the critical section by calling the unlock > > versions instead. > > Since generally the iova would be non-NULL, this seems a reasonable > change (which could be mentioned in the commit log) I think it is too obvious to mention it. There are many things we can mention but we should only mention what's necessary, right? Thanks. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu