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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id AB75FCA0EED for ; Thu, 28 Aug 2025 07:14:44 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 010EC8E0003; Thu, 28 Aug 2025 03:14:44 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id F2AB68E0001; Thu, 28 Aug 2025 03:14:43 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E40488E0003; Thu, 28 Aug 2025 03:14:43 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id D17FF8E0001 for ; Thu, 28 Aug 2025 03:14:43 -0400 (EDT) Received: from smtpin21.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 2C4A31389F5 for ; Thu, 28 Aug 2025 07:14:43 +0000 (UTC) X-FDA: 83825303646.21.05BD148 Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf29.hostedemail.com (Postfix) with ESMTP id 6399D120017 for ; Thu, 28 Aug 2025 07:14:41 +0000 (UTC) Authentication-Results: imf29.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=GIzhXS8P; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf29.hostedemail.com: domain of rppt@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=rppt@kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1756365281; a=rsa-sha256; cv=none; b=i6rCtsEYgyW3OlYnfexBQDn/49NAeeh7uGwxdslOAR799HuDhOsF0/7gctR4f5NC3OSmGw 0S8xLJ2IXJvx1sQ0drPxE3B4LtPXsst4WmU9P6XdSk1RMgyOdKl4IO90IsazL51FOHT+Hn +Vcyd8pZKEBJ3F2tt0etPmCVYVFBhyg= ARC-Authentication-Results: i=1; imf29.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=GIzhXS8P; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf29.hostedemail.com: domain of rppt@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=rppt@kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1756365281; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=eZgqJ9L5N8worhqIqqjXZLxcoaxzXMD11v4lBBZZ+WA=; b=ixBsc4Q0W+U+xRD3fDkN3j1jl3LB79eWd62eZ8GAt/3yMOOtE9QHtLZ/G4k/IbNRkJ6WGn eVJRmHuvKbwpB1whJPf+wM4u75SnQCEsaxla4vhby2F1rmNcgmDt+EJVMIkfxtJ/ZwiJbD ipMkE0GW0cY2y/M/zx4qY+P5wUsO3bE= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id E82A440276; Thu, 28 Aug 2025 07:14:39 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A2CFEC4CEED; Thu, 28 Aug 2025 07:14:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1756365279; bh=u7MU8S7IUKFLA+3rSi4qDipSi5TbBda36l1aewE2udM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=GIzhXS8PSnxYCSsCp5sOq9LQVBuQ368mCesgVvzDRbMdYsHsF986cg37wXBeCyBMt +9JcuR+1Z6xLXbpb50R0WlQlVSU630yE+rXFA13Rz/ar7HDUsG+SQqVQ/qPuaU9PSc st0CQpt/2vSNT+yhe5uzUC96g26FsCxSN3bQiUqxds342dEEdlsQZSDrKvMBsCjaJA XbinE3bU++eTmz6yOUC9S2cjzgETY60Ju2PpaQh3yK3XNsKsgK7Dyky37zuld+l3EI PlxGGISs04ykUysfnAZ+YNhYIGKhbXLwvpl/Khe/e/KH4qf9uCyuGDTImM3somOfat y9luVBQTC6Mkg== Date: Thu, 28 Aug 2025 10:14:14 +0300 From: Mike Rapoport To: Jason Gunthorpe Cc: Pasha Tatashin , pratyush@kernel.org, jasonmiu@google.com, graf@amazon.com, changyuanl@google.com, dmatlack@google.com, rientjes@google.com, corbet@lwn.net, rdunlap@infradead.org, ilpo.jarvinen@linux.intel.com, kanie@linux.alibaba.com, ojeda@kernel.org, aliceryhl@google.com, masahiroy@kernel.org, akpm@linux-foundation.org, tj@kernel.org, yoann.congal@smile.fr, mmaurer@google.com, roman.gushchin@linux.dev, chenridong@huawei.com, axboe@kernel.dk, mark.rutland@arm.com, jannh@google.com, vincent.guittot@linaro.org, hannes@cmpxchg.org, dan.j.williams@intel.com, david@redhat.com, joel.granados@kernel.org, rostedt@goodmis.org, anna.schumaker@oracle.com, song@kernel.org, zhangguopeng@kylinos.cn, linux@weissschuh.net, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, gregkh@linuxfoundation.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, rafael@kernel.org, dakr@kernel.org, bartosz.golaszewski@linaro.org, cw00.choi@samsung.com, myungjoo.ham@samsung.com, yesanishhere@gmail.com, Jonathan.Cameron@huawei.com, quic_zijuhu@quicinc.com, aleksander.lobakin@intel.com, ira.weiny@intel.com, andriy.shevchenko@linux.intel.com, leon@kernel.org, lukas@wunner.de, bhelgaas@google.com, wagi@kernel.org, djeffery@redhat.com, stuart.w.hayes@gmail.com, ptyadav@amazon.de, lennart@poettering.net, brauner@kernel.org, linux-api@vger.kernel.org, linux-fsdevel@vger.kernel.org, saeedm@nvidia.com, ajayachandra@nvidia.com, parav@nvidia.com, leonro@nvidia.com, witu@nvidia.com Subject: Re: [PATCH v3 29/30] luo: allow preserving memfd Message-ID: References: <20250807014442.3829950-1-pasha.tatashin@soleen.com> <20250807014442.3829950-30-pasha.tatashin@soleen.com> <20250826162019.GD2130239@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250826162019.GD2130239@nvidia.com> X-Rspamd-Server: rspam03 X-Rspam-User: X-Rspamd-Queue-Id: 6399D120017 X-Stat-Signature: 6kmbmfbbajoeyjxwhe1u9crcs9zfawyq X-HE-Tag: 1756365281-742509 X-HE-Meta: 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 Hzs2feUR YhRfPpXUBltkT35kva/jdL6hHcvAV0AXC+5FwoctV+N4CF/nrEJugnn+INJDeptsg7zetJuYu3nDvqS2l3d0WECqZ3MopSdZ/zJyUoRmpShumHTsCcifdS1ZOo648J5djKaK5HUgWZRMUZgM+EFLOBeWPRzqPnJnrzrPvuHX2PNq56aYJauxyRuslfu5rABiv3EZA1ExlNwLQ3F6Utylrt0+dVovMvil7m3tVzOQ/HnINQYoKDrBwPhoHWnF+3Dhi9ezvpS6MQKYtHuqImEjWkQWQR9rqpnUOjk1XBXmd0fnKRw4OYhGx5PmLs5TJ7Wvm7evD/ORDO4pYzJU= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Tue, Aug 26, 2025 at 01:20:19PM -0300, Jason Gunthorpe wrote: > On Thu, Aug 07, 2025 at 01:44:35AM +0000, Pasha Tatashin wrote: > > > + err = fdt_property_placeholder(fdt, "folios", preserved_size, > > + (void **)&preserved_folios); > > + if (err) { > > + pr_err("Failed to reserve folios property in FDT: %s\n", > > + fdt_strerror(err)); > > + err = -ENOMEM; > > + goto err_free_fdt; > > + } > > Yuk. > > This really wants some luo helper > > 'luo alloc array' > 'luo restore array' > 'luo free array' > > Which would get a linearized list of pages in the vmap to hold the > array and then allocate some structure to record the page list and > return back the u64 of the phys_addr of the top of the structure to > store in whatever. > > Getting fdt to allocate the array inside the fds is just not going to > work for anything of size. I agree that we need a side-car structure for preserving large (potentially sparse) arrays, but I think it should be a part of KHO rather than LUO. -- Sincerely yours, Mike.