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 C19BC35836F for ; Tue, 17 Mar 2026 09:12:23 +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=1773738743; cv=none; b=X52SXbE9Sn9DFXpMbH9Ij+2LSEtUgU5VMF7EhHtKtbkcPuS+v/J01wC4JHLuEu4+M03FSvsf1CyZa8HLRAibJbf6avXSjmn4DHK1qGiJyfg8aLsDtXx1szVPOQMBKii+dAMrglq9flhsMUk85bKE0krHGxKKACJv6/Xj72A1ptM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773738743; c=relaxed/simple; bh=mg1XRSjP0lyWKLduKNpAhmOLtj6KEMMUpquKvbP4yzo=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=ue+BZige7zsiKI4VD1uOdoX1kn03wGL5NZOh++VplF3r4OYhPDKbwbO/AmwTw8cSotVxZWuGrykF2SnM/c/Pgsmf0omS1nCfIoZBVFsrYJr3jOBDa7botZ5YJVKCjRoZmqpcc8Wm0tfg+7bp1tYYsgkCIe1zogVwa5hoXXsaWfI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=mCZgaD6K; 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="mCZgaD6K" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A3B50C4CEF7; Tue, 17 Mar 2026 09:12:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1773738743; bh=mg1XRSjP0lyWKLduKNpAhmOLtj6KEMMUpquKvbP4yzo=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=mCZgaD6KOl4NSTvradsDqu9gM/HxUVIdrWrJzFCG3NpmQRzxXB6cpFVf7i0XSNUsU sBBhdtVC3l6lOJ6gKK9nyDiKxhm7+JhNmY3pMoBWtjsfFWPR3xt8E5iBfgXdibGoL6 C2d2zx/FUoHViLg4+OOcVbYNrXtg+72aw7pDXGnEsQ4xx72BH5L5eweQQB6EcMhZzC jUjYJkPeMtkj26MK8yF35s38QTxuf9lHnHoAtlI+pgUyqBuI7YS8bc6UVDhWYF4tgn 0VrUCQIQtzOGZY4IS5H2EruN/PN4SICGCPHyUshAIx5ayU6jIV4J539TcrC3l2IFIa Az3X55mxCQJ1g== From: Pratyush Yadav To: Mike Rapoport Cc: Pratyush Yadav , Alexander Graf , Pasha Tatashin , Andrew Morton , kexec@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] kho: drop restriction on maximum page order In-Reply-To: (Mike Rapoport's message of "Tue, 10 Mar 2026 12:33:38 +0200") References: <20260309123410.382308-1-pratyush@kernel.org> <20260309123410.382308-2-pratyush@kernel.org> Date: Tue, 17 Mar 2026 09:12:19 +0000 Message-ID: <2vxzo6kmddl8.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, Mar 10 2026, Mike Rapoport wrote: > On Mon, Mar 09, 2026 at 12:34:07PM +0000, Pratyush Yadav wrote: >> KHO currently restricts the maximum order of a restored page to the >> maximum order supported by the buddy allocator. While this works fine >> for much of the data passed across kexec, it is possible to have pages >> larger than MAX_PAGE_ORDER. >> >> For one, it is possible to get a larger order when using >> kho_preserve_pages() if the number of pages is large enough, since it >> tries to combine multiple aligned 0-order preservations into one higher >> order preservation. >> >> For another, upcoming support for hugepages can have gigantic hugepages >> being preserved over KHO. >> >> There is no real reason for this limit. The KHO preservation machinery >> can handle any page order. Remove this artificial restriction on max >> page order. >> >> Signed-off-by: Pratyush Yadav >> Signed-off-by: Pratyush Yadav (Google) > > One SOB should be enough ;-) Hmm, I figured the unemployed me (who originally wrote the patch) and the employed-by-google me (who is doing this new version) would count as two separate entities and there should be a S-o-b for both. Anyway, I am fine with dropping either one of the two. > > Reviewed-by: Mike Rapoport (Microsoft) Thanks! [...] -- Regards, Pratyush Yadav