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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5B73AC433FE for ; Mon, 11 Apr 2022 10:07:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345097AbiDKKJ5 (ORCPT ); Mon, 11 Apr 2022 06:09:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41042 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243588AbiDKKJ4 (ORCPT ); Mon, 11 Apr 2022 06:09:56 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C33D620BD2; Mon, 11 Apr 2022 03:07:42 -0700 (PDT) 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 ams.source.kernel.org (Postfix) with ESMTPS id 859AEB81195; Mon, 11 Apr 2022 10:07:41 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AD17FC385A4; Mon, 11 Apr 2022 10:07:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1649671660; bh=7d4Fz2YovE5nbd9DXkYQpMdwcvwOp0v8/bguDOqmFSY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=BFtbQd/iq+rlCNPGaxfC3Ir2HvIQQgsq/Vp2+3JtHAGSDwgjp8Xd5w2caZTe8PAXA eHsQqWA1+krPxZyVFaVbYdrqMp8DMvGob+k/4ZGEKf29Ahye/B2GdlV92VVfWYnr8m l0ULaiEvF5/6bu/SR0XQZK85N7o0i8G8+zOPUcz2ilXYjPcdgecr+7alIM6T1xg4PH zYWXQRqH1KSvIhFvCdaJkxSgZKH7wHaLOTRaePBuQBkjmpSc8p0VPiM5Bh9Ds4ELGd g8uGUUGlAY7+59ndecOzR57Fv6XdUEPFsDhoy6VyqJ301LTYFhzVY8yH9yzSysRmHQ GiefvKC1Z25dw== Date: Mon, 11 Apr 2022 13:07:29 +0300 From: Mike Rapoport To: Dave Hansen Cc: "Kirill A. Shutemov" , "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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <6c976344-fdd6-95cd-2cb0-b0e817bf0392@intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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? > > return false; > > > > ? > > That's better. But, aren't the PG_* names usually reserved for real > page->flags bits? That naming might be part of my confusion. We use them for PageType as well like PG_buddy, PG_offline, PG_Table. -- Sincerely yours, Mike.