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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 64BEEC433EF for ; Wed, 29 Jun 2022 11:29:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231807AbiF2L3D (ORCPT ); Wed, 29 Jun 2022 07:29:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33374 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229892AbiF2L3C (ORCPT ); Wed, 29 Jun 2022 07:29:02 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 4DFBA326DC for ; Wed, 29 Jun 2022 04:29:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1656502140; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=ZiMXL+ilFja5jXawjmm60mxTjlG0pAnot2u6S8oxJQ0=; b=gbWAhxExLebE1nuCqpN8mU9Xt5l8lSk6bb6Di2OxRXUf6kEnJgSlpuxX1yw7AN9/0on+pZ RxpJyNasTcCUmbtGRxyR7b3S8c+no4ZDz4pROUteMtAWFGFCcx9/Mg6jZEVzQGAB5L5h0M IWIJqEFxZX6ADqEN5Lgrsw7DkjaSbIc= Received: from mail-wm1-f69.google.com (mail-wm1-f69.google.com [209.85.128.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-179-QLYFLUEPPzCcpvOvcQwmIg-1; Wed, 29 Jun 2022 07:28:59 -0400 X-MC-Unique: QLYFLUEPPzCcpvOvcQwmIg-1 Received: by mail-wm1-f69.google.com with SMTP id z11-20020a05600c0a0b00b003a043991610so6191212wmp.8 for ; Wed, 29 Jun 2022 04:28:58 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=ZiMXL+ilFja5jXawjmm60mxTjlG0pAnot2u6S8oxJQ0=; b=UghRCTb4OCY4cMe0gz8vhoGZryvF4PoHS4SW9zSKmS2mE5tTcyq0yJKDlPaW42LaAH ZXGtCx+vzoJ8c7pwZoFcig/hLvPwI69GBUp6ocw0CHmuklWPspoNzRWKxh7WwEChpOKB 64h1MzhwkhWO8AwERsjbpkbVHlaKCjqGZWPWls/cyjJIUkwA0ud8Xw7ieftaqbji9xvZ +Wv53E3jSh0CfvfJSBW9vHHF/Wq7c5EWlL19J1lc1gxZh8YDpMnXMHSzJdRmP8aQgzPx H5o/FsqtoSKo1KPL74O7yKcTpB3HJo3UOE33in7HwtIUck56Yfud+nBfutA4UG7A5+E1 JwWg== X-Gm-Message-State: AJIora8ykMZ8DZqoKJfk8n9cbw0DchC3537uWUPLaffGZwUtSxAzvMJv VZJnW4IdAdomNuErAG0jCtd/sD5j8i8leBK2fdNXQm75D8GCFjft6jibaOKGhy0kCFCnIpJDUid kVo4UO9r49iOSaAcRaE8gkfRz X-Received: by 2002:adf:d841:0:b0:21d:2d0d:e704 with SMTP id k1-20020adfd841000000b0021d2d0de704mr1882261wrl.77.1656502137607; Wed, 29 Jun 2022 04:28:57 -0700 (PDT) X-Google-Smtp-Source: AGRyM1tZP/KbIe69IZVjJQlbxE5EU9PxxeyQN8aoggsXmiyfSbUGRB0Oc3AxcelAzcQjUt6MTEdKFA== X-Received: by 2002:adf:d841:0:b0:21d:2d0d:e704 with SMTP id k1-20020adfd841000000b0021d2d0de704mr1882246wrl.77.1656502137405; Wed, 29 Jun 2022 04:28:57 -0700 (PDT) Received: from redhat.com ([2.52.23.204]) by smtp.gmail.com with ESMTPSA id q11-20020adfea0b000000b0020fff0ea0a3sm16108515wrm.116.2022.06.29.04.28.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 29 Jun 2022 04:28:56 -0700 (PDT) Date: Wed, 29 Jun 2022 07:28:53 -0400 From: "Michael S. Tsirkin" To: Yongji Xie Cc: Jason Wang , Liu Xiaodong , Maxime Coquelin , Stefan Hajnoczi , virtualization , linux-kernel , songmuchun@bytedance.com Subject: Re: [PATCH 5/6] vduse: Support registering userspace memory for IOTLB Message-ID: <20220629072825-mutt-send-email-mst@kernel.org> References: <20220629082541.118-1-xieyongji@bytedance.com> <20220629082541.118-6-xieyongji@bytedance.com> <20220629043539-mutt-send-email-mst@kernel.org> <20220629055241-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jun 29, 2022 at 06:19:31PM +0800, Yongji Xie wrote: > > No i mean you decrement the lock twice. Question is can two bounce > > buffers share a page? > > > > I think we can't. I will find a way to prevent it. > > Thanks, > Yongji I guess it doesn't matter much then. -- MST