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 2B118EE4983 for ; Tue, 30 Dec 2025 16:27:15 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 93E186B0088; Tue, 30 Dec 2025 11:27:14 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 8E8626B0089; Tue, 30 Dec 2025 11:27:14 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7EAED6B008A; Tue, 30 Dec 2025 11:27:14 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 703EB6B0088 for ; Tue, 30 Dec 2025 11:27:14 -0500 (EST) Received: from smtpin02.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 0A6C31ABED for ; Tue, 30 Dec 2025 16:27:14 +0000 (UTC) X-FDA: 84276667188.02.D2AF46E Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf12.hostedemail.com (Postfix) with ESMTP id 7AD844000C for ; Tue, 30 Dec 2025 16:27:12 +0000 (UTC) Authentication-Results: imf12.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=nJFe4Uey; spf=pass (imf12.hostedemail.com: domain of rppt@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=rppt@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1767112032; 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=Cc7YiftCyK4iK6kMX/CRY41z53S9XjUdaMgEdWd8gxU=; b=mOIOZMJKVOAzsp/7en8Ln/hO7659uC6pOIBHA5zF4dLigt2B2WMqY81u+8owDFAFMMbzRn KpqNX3e8/azF8pIO56MGjgA+4+WNW3DDRUtNLD7nWCYO4nf3sg9/2JOZM3nS26MNna/GF0 Po4d7CU6Yp6arCm09+hN7UmkfG3EsJA= ARC-Authentication-Results: i=1; imf12.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=nJFe4Uey; spf=pass (imf12.hostedemail.com: domain of rppt@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=rppt@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1767112032; a=rsa-sha256; cv=none; b=8lkAiITeR3XGIYtkvyA7OFFxBBEamWhaGWQBoum5TTNOf9yFnAg/CxZSgXeHu00uW9rTBJ fkHsDi5wVwvNsZScVDOUuWM9jB2O1MTbzYYIMlihcKVf7olNSOCc8zU2othKd9YYmCGZ/9 EBweNCx5YtcvquorTdgbOC0FH/8s7XI= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 00E406000A; Tue, 30 Dec 2025 16:27:12 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DB010C19421; Tue, 30 Dec 2025 16:27:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1767112031; bh=URTkQfEAZsZH5uYz347syQqM6OdY1oUoieji2FfUxl8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=nJFe4UeyWaKz9zZyFi8M/Yl+ti0cC3DNxJmjnyVILaLigSgcAWjL8c1z9/GRVLeg+ KZ53Fb9hyXY9X8B4D4oq9cfhoPbHE6j6+UnCLGPZGmog29rqEGZdXHartFEUbkbP6c Hq+A4VymM2CId3nuCPUst9T+/SdYG7s4dO5p3zKgL4Vojbt4N3hrv37CiWXplVVDFo JwLMQfLGxq+H5HjIp2z/mYIoGmdyuMCe2Au9ISc+X1FcVN3Ls3MHz7RhctN4ZDPCD6 yL8mTOaZDUe2CV8+esu8STEotLp4kP0s9FdYSHzDiXPYc862olBt1Hid09o2F33bfg jUiE0Oq3Az5cg== Date: Tue, 30 Dec 2025 18:27:06 +0200 From: Mike Rapoport To: Pasha Tatashin Cc: akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, pratyush@kernel.org Subject: Re: [PATCH v3] liveupdate: separate memfd support into LIVEUPDATE_MEMFD Message-ID: References: <20251230161402.1542099-1-pasha.tatashin@soleen.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20251230161402.1542099-1-pasha.tatashin@soleen.com> X-Rspamd-Server: rspam02 X-Stat-Signature: ao54y874qne9399fy5jd17kzppy7f5pm X-Rspam-User: X-Rspamd-Queue-Id: 7AD844000C X-HE-Tag: 1767112032-749794 X-HE-Meta: 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 Syba2TkM 31Siuyay05kEmkAVLl0DRMopWiAE4e7o1AdZmbqL4a/jHiZxF22mXRiy3g6jFWL1KsqPIjOnYxQoMWkIy3QmzWOA7PjvtOTsu+E/YAxzmMoOwT5sR9i6TKBdG5fVu32Mk5WkD+pdkoNhj50GGbhuxGI0kLrMm34tiVWJ2ppTEAmtX3ojvCD8poreDiBT1vTK/wWojoSaBXIp1Z91WIg43SBah5eBAXkI3nuuaBvWMc6KWIXjQZclL2H3bfXZFPlccIiwZeEbCVd9PNtc12xFGO7jtUG5c7mAYu/cyhVxlP3xkT3/qdhCH8RSKsrc/7VHae4vmrG7C94Hs4HU6iT8XSkRQhSHNlrRIk7w/uGlIgt+buWZ0CWHpvHKWMALCXi++NNx0 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, Dec 30, 2025 at 11:14:02AM -0500, Pasha Tatashin wrote: > Decouple memfd preservation support from the core Live Update > Orchestrator configuration. > > Previously, enabling CONFIG_LIVEUPDATE forced a dependency on > CONFIG_SHMEM and unconditionally compiled memfd_luo.o. However, Live > Update may be used for purposes that do not require memfd-backed memory > preservation. > > Introduce CONFIG_LIVEUPDATE_MEMFD to gate memfd_luo.o. This moves the > SHMEM and MEMFD_CREATE dependencies to the specific feature that needs > them, allowing the base LIVEUPDATE option to be selected independently > of shared memory support. > > Signed-off-by: Pasha Tatashin > Reviewed-by: Pratyush Yadav Reviewed-by: Mike Rapoport (Microsoft) > --- > Changes v3 > - Addressed Mike's suggestion: added default LIVEUPDATE, and removed > config from selftests. > > kernel/liveupdate/Kconfig | 17 ++++++++++++++++- > mm/Makefile | 2 +- > 2 files changed, 17 insertions(+), 2 deletions(-) > > diff --git a/kernel/liveupdate/Kconfig b/kernel/liveupdate/Kconfig > index d2aeaf13c3ac..1a8513f16ef7 100644 > --- a/kernel/liveupdate/Kconfig > +++ b/kernel/liveupdate/Kconfig > @@ -54,7 +54,6 @@ config KEXEC_HANDOVER_ENABLE_DEFAULT > config LIVEUPDATE > bool "Live Update Orchestrator" > depends on KEXEC_HANDOVER > - depends on SHMEM > help > Enable the Live Update Orchestrator. Live Update is a mechanism, > typically based on kexec, that allows the kernel to be updated > @@ -73,4 +72,20 @@ config LIVEUPDATE > > If unsure, say N. > > +config LIVEUPDATE_MEMFD > + bool "Live update support for memfd" > + depends on LIVEUPDATE > + depends on MEMFD_CREATE > + depends on SHMEM > + default LIVEUPDATE > + help > + Enable live update support for memfd regions. This allows preserving > + memfd-backed memory across kernel live updates. > + > + This can be used to back VM memory with memfds, allowing the guest > + memory to persist, or for other user workloads needing to preserve > + pages. > + > + If unsure, say N. > + > endmenu > diff --git a/mm/Makefile b/mm/Makefile > index 9175f8cc6565..798f04233d71 100644 > --- a/mm/Makefile > +++ b/mm/Makefile > @@ -100,7 +100,7 @@ obj-$(CONFIG_NUMA) += memory-tiers.o > obj-$(CONFIG_DEVICE_MIGRATION) += migrate_device.o > obj-$(CONFIG_TRANSPARENT_HUGEPAGE) += huge_memory.o khugepaged.o > obj-$(CONFIG_PAGE_COUNTER) += page_counter.o > -obj-$(CONFIG_LIVEUPDATE) += memfd_luo.o > +obj-$(CONFIG_LIVEUPDATE_MEMFD) += memfd_luo.o > obj-$(CONFIG_MEMCG_V1) += memcontrol-v1.o > obj-$(CONFIG_MEMCG) += memcontrol.o vmpressure.o > ifdef CONFIG_SWAP > -- > 2.52.0.351.gbe84eed79e-goog > -- Sincerely yours, Mike.