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[2620:137:e000::1:20]) by mx.google.com with ESMTP id v18-20020a509552000000b0042bcd41832fsi3427025eda.400.2022.07.01.21.27.23; Fri, 01 Jul 2022 21:27:48 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@linux-foundation.org header.s=korg header.b=X2UjaxB7; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231866AbiGBEYL (ORCPT + 99 others); Sat, 2 Jul 2022 00:24:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57502 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229538AbiGBEYI (ORCPT ); Sat, 2 Jul 2022 00:24:08 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C5DF827CF7; Fri, 1 Jul 2022 21:24:05 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 64D0260C32; Sat, 2 Jul 2022 04:24:05 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CF9A0C341C7; Sat, 2 Jul 2022 04:24:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1656735844; bh=0JxhHAplfI63oB/NzCnRqg7Nzu+/8/KjAvBoeKJIaJY=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=X2UjaxB7lVcvMqDmSNFUBUuvl8wh3eEfB1LTc9Z9xTkwQMSqHY4js3IBGTpNNcYoL m1/60T5cdPbZRoW8JkGhbbeo5i8clmn65j1+qMCZnq1sIpDs3dXCKVdFNZhgorIDpq etEsUljuPoIoFHxAE7ZaLMsjLcLQ68CbmcnPajL8= Date: Fri, 1 Jul 2022 21:24:03 -0700 From: Andrew Morton To: Khalid Aziz Cc: willy@infradead.org, aneesh.kumar@linux.ibm.com, arnd@arndb.de, 21cnbao@gmail.com, corbet@lwn.net, dave.hansen@linux.intel.com, david@redhat.com, ebiederm@xmission.com, hagen@jauu.net, jack@suse.cz, keescook@chromium.org, kirill@shutemov.name, kucharsk@gmail.com, linkinjeon@kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, longpeng2@huawei.com, luto@kernel.org, markhemm@googlemail.com, pcc@google.com, rppt@kernel.org, sieberf@amazon.com, sjpark@amazon.de, surenb@google.com, tst@schoebel-theuer.de, yzaikin@google.com Subject: Re: [PATCH v2 0/9] Add support for shared PTEs across processes Message-Id: <20220701212403.77ab8139b6e1aca87fae119e@linux-foundation.org> In-Reply-To: References: X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-7.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,NICE_REPLY_A,RCVD_IN_DNSWL_HI, SPF_HELO_NONE,SPF_PASS,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 29 Jun 2022 16:53:51 -0600 Khalid Aziz wrote: > This patch series implements a mechanism in kernel to allow > userspace processes to opt into sharing PTEs. It adds a new > in-memory filesystem - msharefs. Dumb question: why do we need a new filesystem for this? Is it not feasible to permit PTE sharing for mmaps of tmpfs/xfs/ext4/etc files?