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 X-Spam-Level: X-Spam-Status: No, score=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 535E9C2D0E4 for ; Tue, 17 Nov 2020 21:10:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EA31924181 for ; Tue, 17 Nov 2020 21:10:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="fYMULdu+" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726136AbgKQVKN (ORCPT ); Tue, 17 Nov 2020 16:10:13 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47792 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725823AbgKQVKN (ORCPT ); Tue, 17 Nov 2020 16:10:13 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 23F9EC0613CF; Tue, 17 Nov 2020 13:10:13 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=Ri91W8ocs5j1kEkJ2qPP/wzX2scE1yNyfb4YmTpxrH4=; b=fYMULdu+st/sND/Y5nBpk1vwEM ZQqyFcbp0+JR5ZHTbEAnEyhsAspAv47XXzbUVytwqPrGuBFzZ8bwuWkg1WO89PU4uFmLgdz4XwFga AOJbkcINoGPsc9xC6lZpMV2dUVuivhAnGHstzSLmu8zPC0tp4fiNgagOr+eKyGKxM1FUZx3PaG5Sv p9TkaJpnsVGA2nyBr10k911eb9a9OoieU95yaxy7ZO6tgiTsP9g8uOMJnXDnkQrWEHqs3wZsiihkf E2RvJ200E479oTK+PrsvX407onFO8I0qmu4VInGHtJyt1cmi2Se0JPJ469qJTwHyTbCc6TC2pJBhG SSixLeNw==; Received: from willy by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1kf8Ej-0003Zr-8e; Tue, 17 Nov 2020 21:10:01 +0000 Date: Tue, 17 Nov 2020 21:10:01 +0000 From: Matthew Wilcox To: Zi Yan Cc: linux-mm@kvack.org, "Kirill A . Shutemov" , Roman Gushchin , Andrew Morton , linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, Yang Shi , Michal Hocko , John Hubbard , Ralph Campbell , David Nellans Subject: Re: [RFC PATCH 3/6] mm: page_owner: add support for splitting to any order in split page_owner. Message-ID: <20201117211001.GY29991@casper.infradead.org> References: <20201111204008.21332-1-zi.yan@sent.com> <20201111204008.21332-4-zi.yan@sent.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201111204008.21332-4-zi.yan@sent.com> Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org On Wed, Nov 11, 2020 at 03:40:05PM -0500, Zi Yan wrote: > - for (i = 0; i < nr; i++) { > + for (i = 0; i < nr; i += (1 << new_order)) { > page_owner = get_page_owner(page_ext); > - page_owner->order = 0; > + page_owner->order = new_order; > page_ext = page_ext_next(page_ext); > } This doesn't do what you're hoping it will. It's going to set ->order to new_order for the first N pages instead of every 1/N pages. You'll need to do something like page_ext = lookup_page_ext(page + i); or add a new page_ext_add(page_ext, 1 << new_order);