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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id EEAD4C433F5 for ; Wed, 13 Apr 2022 14:48:25 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 4FEDF6B0072; Wed, 13 Apr 2022 10:48:25 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 486F56B0073; Wed, 13 Apr 2022 10:48:25 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 300E56B0074; Wed, 13 Apr 2022 10:48:25 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0109.hostedemail.com [216.40.44.109]) by kanga.kvack.org (Postfix) with ESMTP id 218946B0072 for ; Wed, 13 Apr 2022 10:48:25 -0400 (EDT) Received: from smtpin21.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id D5E58A9444 for ; Wed, 13 Apr 2022 14:48:24 +0000 (UTC) X-FDA: 79352136528.21.4D2E9D3 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf15.hostedemail.com (Postfix) with ESMTP id 54069A0009 for ; Wed, 13 Apr 2022 14:48:24 +0000 (UTC) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 9B29E61C40; Wed, 13 Apr 2022 14:48:23 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DDB28C385A4; Wed, 13 Apr 2022 14:48:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1649861303; bh=FgczV9vyyhtmBq+7sQB2zbK2zkbVOySmGyJEOuInnlc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=TQw7UBPRl43qPWUCP2erzWWaWPQNsx70yocpG64iBv2l/aAtgrwO3qsNv+dq2+Ch5 JU7LOh8SUpkXyAOfn0+SnN+NSLeR0dhUGW+m4a7/20guJtrgLblegv5sNemLcgPqKl 6J9FTjAKTpFtGRTENxV8SurPZxzU+o/DiJl5sBZXY5wBhL1MObXsp+5qrg/fRxl1JX x9+TXStgVboZIpoQYAV1bAyaKsDvgEai2GQhwx1z7TDTwAp5kz7qfxpKf9bfGC8w8k OETaHeX9pWfVR+5+xQP4RoU2bnZst5FCD2aKRDDi1+lWvsAToUjeX4fbXza6rrXPK2 UlrExmZwnqSbw== Date: Wed, 13 Apr 2022 17:48:09 +0300 From: Mike Rapoport To: "Kirill A. Shutemov" Cc: Dave Hansen , "Kirill A. Shutemov" , Borislav Petkov , Andy Lutomirski , Sean Christopherson , Andrew Morton , Joerg Roedel , Ard Biesheuvel , Andi Kleen , Kuppuswamy Sathyanarayanan , David Rientjes , Vlastimil Babka , Tom Lendacky , Thomas Gleixner , Peter Zijlstra , Paolo Bonzini , Ingo Molnar , Varad Gautam , Dario Faggioli , Brijesh Singh , David Hildenbrand , x86@kernel.org, linux-mm@kvack.org, linux-coco@lists.linux.dev, linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org, Mike Rapoport Subject: Re: [PATCHv4 1/8] mm: Add support for unaccepted memory Message-ID: References: <20220405234343.74045-1-kirill.shutemov@linux.intel.com> <20220405234343.74045-2-kirill.shutemov@linux.intel.com> <767c2100-c171-1fd3-6a92-0af2e4bf3067@intel.com> <20220409155423.iv2arckmvavvpegt@box.shutemov.name> <6c976344-fdd6-95cd-2cb0-b0e817bf0392@intel.com> <20220413114001.wdsi2xrm4btrghms@box.shutemov.name> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220413114001.wdsi2xrm4btrghms@box.shutemov.name> X-Rspamd-Server: rspam09 X-Rspam-User: X-Stat-Signature: yj7iq1r6wq1hfx5fuznnu1rr34skpkwt Authentication-Results: imf15.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=TQw7UBPR; dmarc=pass (policy=none) header.from=kernel.org; spf=pass (imf15.hostedemail.com: domain of rppt@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=rppt@kernel.org X-Rspamd-Queue-Id: 54069A0009 X-HE-Tag: 1649861304-658917 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, Apr 13, 2022 at 02:40:01PM +0300, Kirill A. Shutemov wrote: > On Mon, Apr 11, 2022 at 01:07:29PM +0300, Mike Rapoport wrote: > > On Sun, Apr 10, 2022 at 11:38:08PM -0700, Dave Hansen wrote: > > > On 4/9/22 08:54, Kirill A. Shutemov wrote: > > > > On Fri, Apr 08, 2022 at 11:55:43AM -0700, Dave Hansen wrote: > > > > > > >>> if (fpi_flags & FPI_TO_TAIL) > > > >>> to_tail = true; > > > >>> else if (is_shuffle_order(order)) > > > >>> @@ -1149,7 +1192,8 @@ static inline void __free_one_page(struct page *page, > > > >>> static inline bool page_expected_state(struct page *page, > > > >>> unsigned long check_flags) > > > >>> { > > > >>> - if (unlikely(atomic_read(&page->_mapcount) != -1)) > > > >>> + if (unlikely(atomic_read(&page->_mapcount) != -1) && > > > >>> + !PageUnaccepted(page)) > > > >>> return false; > > > >> > > > >> That probably deserves a comment, and maybe its own if() statement. > > > > > > > > Own if does not work. PageUnaccepted() is encoded in _mapcount. > > > > > > > > What about this: > > > > > > > > /* > > > > * page->_mapcount is expected to be -1. > > > > * > > > > * There is an exception for PageUnaccepted(). The page type can be set > > > > * for pages on free list. Page types are encoded in _mapcount. > > > > * > > > > * PageUnaccepted() will get cleared in post_alloc_hook(). > > > > */ > > > > if (unlikely((atomic_read(&page->_mapcount) | PG_unaccepted) != -1)) > > > > Maybe I'm missing something, but isn't this true for any PageType? > > PG_buddy gets clear on remove from the free list, before the chec. > > PG_offline and PG_table pages are never on free lists. Right, this will work 'cause PageType is inverted. I still think this condition is hard to parse and I liked the old variant with !PageUnaccepted() better. Maybe if we wrap the whole construct in a helper it will be less eye hurting. > -- > Kirill A. Shutemov -- Sincerely yours, Mike.