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=-4.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,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 78A4DC433E0 for ; Thu, 11 Feb 2021 11:31:20 +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 16DA864DCF for ; Thu, 11 Feb 2021 11:31:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 16DA864DCF Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=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=2BiJAepoPd4oZ0htOLzlr/Xj210OqFoi/kEGXuM6LC4=; b=w7yuAhc9Gh5R0K/KqdPOzWHKt 8nnR7SKEWASviEgcQ2lT5EXc1RDGfpjBD5o+ZetPWHQ8/r41rfivXMjy58BXRrMwGy4mx81/aZxUM Mnm+/Zv6hwipEPsiW1we8a/OLSVcLcfkVR0Txh55g6UXo2zrUfFEtVp67LxV81DgGgc+Tuao4e8a9 hf5hHeO1H1UE6hWio5Jd+NpQfU5ZBAjFXzvRKwptm9z4SihQAkEfoPg1NJgt1XDHdXdXzOe0MWpEG RHK02qfhETy9fHmdYe95nD1nV+/uzyTuW0P2ODmgIm1awspVVhXLJr1mZPjdibJsE5/sENK3IiMna 0pRxVi3fg==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1lAAAh-00076E-Qi; Thu, 11 Feb 2021 11:30:07 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1lAAAf-00074t-1E; Thu, 11 Feb 2021 11:30:06 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id 2C89C601FF; Thu, 11 Feb 2021 11:29:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1613043004; bh=JtJHuqvnhxNyM0cSP3Qe3tSMfjdJGVz3S+tERJXfo4M=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=PEXygoi6R9pVpb0NPj47+Ko3f1Ah21CxDjueYWnlQAO/uRVErOda0UIyi9V6v9rYs 6NXsauRjapfptBwBvo70ls3AAnv08VDhhWUxi7yLuKhQOTQa31mGOOLAdVpQ8B16uZ SzyBJMAmkReTwWmxT4Tjvg8ZAL2HyRIawjk70IsH5WPDvqJ9dQdETycAuzkDATgNju gOL/aozy2VFMdzBaSlauwv+UBb82EKAQG3vL++P2TTqj9pWtgKqRk4VcEXI1wyFYG+ 5DJMf90zHF2E2ie9ZUU2VlL1vbBwnzXXk30WzSnRm7nZHI33uXE/tbEgH+TreMHc5x BblQZ8rwiMN2Q== Date: Thu, 11 Feb 2021 13:29:46 +0200 From: Mike Rapoport To: David Hildenbrand Subject: Re: [PATCH v17 07/10] mm: introduce memfd_secret system call to create "secret" memory areas Message-ID: <20210211112946.GJ242749@kernel.org> References: <20210208212605.GX242749@kernel.org> <20210209090938.GP299309@linux.ibm.com> <20210211071319.GF242749@kernel.org> <0d66baec-1898-987b-7eaf-68a015c027ff@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210211_063005_196657_4E909566 X-CRM114-Status: GOOD ( 15.82 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Michal Hocko , Peter Zijlstra , Catalin Marinas , Dave Hansen , linux-mm@kvack.org, linux-kselftest@vger.kernel.org, "H. Peter Anvin" , Christopher Lameter , Shuah Khan , Thomas Gleixner , Elena Reshetova , linux-arch@vger.kernel.org, Tycho Andersen , linux-nvdimm@lists.01.org, Will Deacon , x86@kernel.org, Matthew Wilcox , Mike Rapoport , Ingo Molnar , Michael Kerrisk , Palmer Dabbelt , Arnd Bergmann , James Bottomley , Hagen Paul Pfeifer , Borislav Petkov , Alexander Viro , Andy Lutomirski , Paul Walmsley , "Kirill A. Shutemov" , Dan Williams , linux-arm-kernel@lists.infradead.org, linux-api@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, Palmer Dabbelt , linux-fsdevel@vger.kernel.org, Shakeel Butt , Andrew Morton , Rick Edgecombe , Roman Gushchin Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Feb 11, 2021 at 11:02:07AM +0100, David Hildenbrand wrote: > > Another thought regarding "doesn't have _any_ backing storage" > > What are the right semantics when it comes to memory accounting/commit? > > As secretmem does not have > a) any backing storage > b) cannot go to swap > > The MAP_NORESERVE vs. !MAP_NORESERVE handling gets a little unclear. Why > "reserve swap space" if the allocations cannot ever go to swap? Sure, we > want to "reserve physical memory", but in contrast to other users that can > go to swap. > > Of course, this is only relevant for MAP_PRIVATE secretmem mappings. Other > MAP_SHARED assumes there is no need for reserving swap space as it can just > go to the backing storage. (yeah, tmpfs/shmem is weird in that regard as > well, but again, it's a bit different) In that sense seceremem is as weird as tmpfs and it only allows MAP_SHARED. -- Sincerely yours, Mike. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel