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 728B03587A2 for ; Tue, 17 Mar 2026 11:04:21 +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=1773745461; cv=none; b=ARWfnLK8rrCac36pHERs5a2vk1WHLwVGFTEMxqb+dRC5uhRSjgGCwdiJ8ejUaPAHqMPl3cb2NvwuIi51YTKaTU3szRJY/F7IFOCBim+7izc1yFFEmj07J4H+D+fHu7G7dkssPSQMjcFtgvcy+qvFQ9wkB/y3eXCsKL0GbBtKul0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773745461; c=relaxed/simple; bh=FzN+JR6wTdlWoYca/iDWtBJ00teqmkhdZDjQECTdE30=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=aRmyl+bkTBRyjnalZ1C/xHG19alG5+TLkBWlN1fbmhNMBTQxQ+Q4su55m5ag4Ux2bl1b6zBKTxKQqSSVsXOLZHhM7YRJnz4BKt6R7lDMPFQW+pSkV7GEditl42zlXjEKnne8bgNC7Bdh+Qj0zLORGP/iVeD1CizLo9NQDbpthPg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=CzqjY0Gp; 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="CzqjY0Gp" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D6C76C4CEF7; Tue, 17 Mar 2026 11:04:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1773745461; bh=FzN+JR6wTdlWoYca/iDWtBJ00teqmkhdZDjQECTdE30=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=CzqjY0GpYRBoRH5wfJ7qOPgfofiRN3ukCODjKqJ9Otaoj5ox0eR5hogOK9BhTiIdC HaiICmEpGcxK5rPTcirhIp7HnQ0Vowjb+FmsAJGJRZzQwuDqULh31j3ENf5VTj4xmv dqT1UOqBkgSWTAWbgKE2VvrXBGE7d1H8LIWeIHhcynIPPNFlpON3BdTstI3U+abwlb NOeju95h6yOj8SnR4ot4yLZC9vii4975H7Wk9sjdr75PeqEiG25fp732DOlR5TQduu 4W+yiV9Mhq5WWjCn/dZCJWutSSeMyV814jn5Dms4tAT3nVD8MKm6DNUMw9s0FOdaiJ DfCY9fH/rgJfQ== Date: Tue, 17 Mar 2026 13:04:15 +0200 From: Mike Rapoport To: Pratyush Yadav Cc: 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 Message-ID: References: <20260309123410.382308-1-pratyush@kernel.org> <20260309123410.382308-2-pratyush@kernel.org> <2vxzo6kmddl8.fsf@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2vxzo6kmddl8.fsf@kernel.org> On Tue, Mar 17, 2026 at 09:12:19AM +0000, Pratyush Yadav wrote: > 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. Maybe than something like: Signed-off-by: Pratyush Yadav (Hobbyist) Signed-off-by: Pratyush Yadav (Google) ;-) > Anyway, I am fine with dropping either one of the two. > > > > > Reviewed-by: Mike Rapoport (Microsoft) > > Thanks! > > [...] > > -- > Regards, > Pratyush Yadav -- Sincerely yours, Mike.