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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A4EB0EA811B for ; Tue, 10 Feb 2026 13:55:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type:MIME-Version: Message-ID:Date:References:In-Reply-To:Subject:Cc:To:From:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=8sD0GLwSYXIdm9e+BN8o4k7OyBkQyu546gqHQCZm6No=; b=JIEWotk0H6QhonvdDhoROmVunv 3XYFwsGWvIv7ZK0Yf6lLb98Jh1bnx025gI758AgTMcE/TsyGfl+zOyMxXyD8MqzC8F3l7RD91IMLK K6GGVAmuUDaahXRS0qw/T+KBoSGrOxljC6ePqJt32r831g/Zj8abayBFCcRrSvVM20AJgqCOAHnDs lKIi/gog/KbC1o8dN/MsWE89BvGJS6zLrZrK7aV6NJFwyOtE4JeBY0HuSi1sjOIrjFb5Y1E4W5rEy ZOQgkKFrVu2NG+ZPjF4Pyp2v+h9wdn1h65TR30CV0aRWM1Wec8EL6nddN/mk0lR/DXx0BC2q2vicX KaO8gaMw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vpoDA-0000000H1C8-28aG; Tue, 10 Feb 2026 13:55:28 +0000 Received: from tor.source.kernel.org ([2600:3c04:e001:324:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vpoD9-0000000H1Bo-0jA7 for kexec@lists.infradead.org; Tue, 10 Feb 2026 13:55:27 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 6200E60097; Tue, 10 Feb 2026 13:55:26 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6240BC116C6; Tue, 10 Feb 2026 13:55:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1770731726; bh=JE2m8NIaql1tE2VnNeufIkHeTWlYa03U2mH/McAh6Hk=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=iYIHdFRLbDb9dyt6VlP4jwIQGdzjgP4C0/I3oSr8QEKEq5jTwwRZJUrRJtOzzA3d3 ul3zgxJmUr3HgWkJ9HBsTJhVcnU6ZtPIV+vw4ytNw5WIWXRjsP8lMqQVR5eP/ZLhvg gI/eXdV6aJ9aetiEmcgNqbvi75ULz9BNpcAHx5TN+sw/9PfvzzJHmZc57gBXFB11Tf 9X9MSeHPJPU+WhI5/mPpj2wApuaADExGIrm2td5yuTzfHvXfi+U9wpB1Fm+hFe+Wmc tvEEIlVNrrB4Ss88kZIoM+FhYl4NG7IQUEtReipVIXgHjLdNh2X6kUfDrpRyr/hDsl qZ1v9M/CP76+Q== From: Pratyush Yadav To: Michal Clapinski Cc: Evangelos Petrongonas , Pasha Tatashin , Mike Rapoport , Pratyush Yadav , Alexander Graf , kexec@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrew Morton Subject: Re: [PATCH v2] kho: add support for deferred struct page init In-Reply-To: <20260210130418.297153-1-mclapinski@google.com> (Michal Clapinski's message of "Tue, 10 Feb 2026 14:04:18 +0100") References: <20260210130418.297153-1-mclapinski@google.com> Date: Tue, 10 Feb 2026 14:55:22 +0100 Message-ID: <2vxzecmssnxx.fsf@kernel.org> User-Agent: Gnus/5.13 (Gnus v5.13) MIME-Version: 1.0 Content-Type: text/plain X-BeenThere: kexec@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "kexec" Errors-To: kexec-bounces+kexec=archiver.kernel.org@lists.infradead.org On Tue, Feb 10 2026, Michal Clapinski wrote: > When `CONFIG_DEFERRED_STRUCT_PAGE_INIT` is enabled, struct page > initialization is deferred to parallel kthreads that run later > in the boot process. > > During KHO restoration, `deserialize_bitmap()` writes metadata for > each preserved memory region. However, if the struct page has not been > initialized, this write targets uninitialized memory, potentially > leading to errors like: > ``` > BUG: unable to handle page fault for address: ... > ``` > > Fix this by introducing `kho_get_preserved_page()`, which ensures > all struct pages in a preserved region are initialized by calling > `init_deferred_page()` which is a no-op when deferred init is disabled > or when the struct page is already initialized. > > Signed-off-by: Evangelos Petrongonas > Signed-off-by: Michal Clapinski Reviewed-by: Pratyush Yadav (Google) [...] -- Regards, Pratyush Yadav