From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7EAD934C818 for ; Tue, 10 Feb 2026 13:55:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770731726; cv=none; b=cyzR2hQhknz1nzcBdFnZA27ZydgnsD36uMqDAx7vRmzzAQR/4Qr8aYqgjuxokFY5ac06ZnP0Ueo03AO2CzmLlclL76eStHLFYV/AqUku9mnf1Yul6dFYKkq9J3XqHimM0xqk3aXEH5wKEvd1sYg/3k8CD0jNMEbKd50oVHQlMJg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770731726; c=relaxed/simple; bh=JE2m8NIaql1tE2VnNeufIkHeTWlYa03U2mH/McAh6Hk=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=U3w/fe2hsdb6Xrq6niPaGCEXg31mA34LvGWaEX1GuvzFzkCmtigAsrTW2RbIcNEJhQR9JygGynV4gFS932bIaizEUThpjqFbzMQWa981e4FxJJSmAkutDrQbjc+ucOXzNJQqREYrGYtNw0AYeB2ylX7cG/ePyLaCZmSxfZZjMXE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=iYIHdFRL; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="iYIHdFRL" 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) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain 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