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 A4D7FF3381E for ; Tue, 17 Mar 2026 09:12:28 +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=CLI/bZM+cSBD8wVwTESyfSKw+Jwsxjddwt/oR6H0SR0=; b=pYZouO/FkKyk0ue5oOY9TqcLWR Ki27MxcIftji8KKKrtLlHUBq535T4R/frNwzWrVet1CEiycQVO7BfW7G1IlhTFQZtHJZ+d0GDLwKj N3iqD/GaNnZFdcgnfmi+UoiMtSRMP4NX6ghnhMQzFkCAyxWdeVrvUTgmWVCAlboHl3qVAaf+BaGgs g0HVBcgb3I+Ml05T3DJy+hbhUAgv13tLx/ikoCxmPlPAwD5J8DO24ghUCwPyyw7dS9oDqApUJO4+I 5bT401P0kxFfxBmKkT/Qj5ivKIoPPwJxts1QHAeapM/ki0DvpUOwoPHt62hb6lg6tc9OUKH67z/E5 sk3fqhkw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1w2QTR-00000005omg-498U; Tue, 17 Mar 2026 09:12:25 +0000 Received: from sea.source.kernel.org ([172.234.252.31]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1w2QTQ-00000005oll-0sDU for kexec@lists.infradead.org; Tue, 17 Mar 2026 09:12:25 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 78CFC434DC; Tue, 17 Mar 2026 09:12:23 +0000 (UTC) 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) MIME-Version: 1.0 Content-Type: text/plain X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260317_021224_268719_87BE8A78 X-CRM114-Status: GOOD ( 12.20 ) 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, 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