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 071F7C433F5 for ; Fri, 7 Jan 2022 13:41:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347621AbiAGNlD (ORCPT ); Fri, 7 Jan 2022 08:41:03 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33562 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238856AbiAGNlC (ORCPT ); Fri, 7 Jan 2022 08:41:02 -0500 Received: from mail-ed1-x534.google.com (mail-ed1-x534.google.com [IPv6:2a00:1450:4864:20::534]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 69A2FC061574 for ; Fri, 7 Jan 2022 05:41:01 -0800 (PST) Received: by mail-ed1-x534.google.com with SMTP id z9so22159725edm.10 for ; Fri, 07 Jan 2022 05:41:01 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=date:from:to:cc:subject:message-id:reply-to:references:mime-version :content-disposition:in-reply-to:user-agent; bh=1xWMzox84ooh/x8FbxrfvG4p5MAAAWHgM5SqmxnFrYA=; b=ki55QVTGaIkvPjw4miNywVK8IpBgwE9/wxJlYhUiqDVbVgChSFhhkVl/4fOzoHI/Eh I3fbG73ReEQw6Qwfymsb7DYAejTCaTjyckW6HcWsBHo/p6xSeJhzb/i2f1F4eHzEQDl5 oc63Ot53zn4Ak6Ew6R6QYtb5dAb+8bV8x1HTQelzjCiwofGk51soUR53VdPCyHdqdwqC EJisxsICcm/JmE3/MqpqkePklKPda1+/+QRIo5lTichLmLWnfyeXs2+GrH4iMGGwuAHC 7pEvaW0erHBWzIIz2+e5gcHbQFYNU+lxBSUoDV1gQvfqgTGw1tjrSEdmC3HOFXplPrG+ IbQQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:reply-to :references:mime-version:content-disposition:in-reply-to:user-agent; bh=1xWMzox84ooh/x8FbxrfvG4p5MAAAWHgM5SqmxnFrYA=; b=TnVp9fbxv1uJFaJXdeosuHtcwbungwc1pUgVavPqz+QS0DRPZBZlfUYNxDDRaFqdSr 1gR/MTbR5vG87LvFZNJKfmKXz2Bz8PVQ1BaKAPLpsKHPv+nKsDpq2ARstlYnF0bEN2qn NeqKPdRp6pQlvftxeeCudiHYItMyUw9ubWhQZfg5/aKGgOa4Lj3RZQuvpVBApPlrAWo/ dp0Kz8IHGgw3OUWSCTXRtH60A5txY/LFlSXl1J3oRPzSFam7U5TFRJh6DF70uw7A0WOW HmQhCo7azzIoPls+R9njaDmnVAJkHF2Tc8Fo9M999j57jz8wdQILOrt/CKOq8Q815zc4 CImg== X-Gm-Message-State: AOAM531cjXE/w5xWcSOR9Ooo+77Mkgp+E4qJwaV/zk76rhHGJuON/XZ9 fsr16tDRG582FwHZkGxtlnU= X-Google-Smtp-Source: ABdhPJxPjVy6H5PJMWQNyO0yHLYRY16ttpNAMDbsUkoD3k43oeZR4VdaMLnzXjQtHCYUAUeAFutv/A== X-Received: by 2002:a05:6402:35c2:: with SMTP id z2mr63226104edc.136.1641562860061; Fri, 07 Jan 2022 05:41:00 -0800 (PST) Received: from localhost ([185.92.221.13]) by smtp.gmail.com with ESMTPSA id 20sm1413896ejy.105.2022.01.07.05.40.59 (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Fri, 07 Jan 2022 05:40:59 -0800 (PST) Date: Fri, 7 Jan 2022 13:40:59 +0000 From: Wei Yang To: Matthew Wilcox Cc: Wei Yang , peterz@infradead.org, akpm@linux-foundation.org, vbabka@suse.cz, will@kernel.org, linyunsheng@huawei.com, aarcange@redhat.com, feng.tang@intel.com, ebiederm@xmission.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm: remove offset check on page->compound_head and folio->lru Message-ID: <20220107134059.flxr2hcd6ilb6vt7@master> Reply-To: Wei Yang References: <20220106235254.19190-1-richard.weiyang@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20170113 (1.7.2) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jan 07, 2022 at 03:59:01AM +0000, Matthew Wilcox wrote: >On Thu, Jan 06, 2022 at 11:52:54PM +0000, Wei Yang wrote: >> FOLIO_MATCH() is used to make sure struct page and folio has identical >> layout for the first several words. >> >> The comparison of offset between page->compound_head and folio->lru is >> more like an internal check in struct page. >> >> This patch just removes it. >> >> Signed-off-by: Wei Yang > >No. Hi, Matthew Would you mind sharing some insight on this check? -- Wei Yang Help you, Help me