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=-6.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=ham 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 F2F01C433E0 for ; Wed, 8 Jul 2020 08:27:03 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id A819B2078D for ; Wed, 8 Jul 2020 08:27:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=shutemov-name.20150623.gappssmtp.com header.i=@shutemov-name.20150623.gappssmtp.com header.b="k96D0LhG" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A819B2078D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=shutemov.name Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 481AE8D0032; Wed, 8 Jul 2020 04:27:03 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 431838D000D; Wed, 8 Jul 2020 04:27:03 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 36E628D0032; Wed, 8 Jul 2020 04:27:03 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0079.hostedemail.com [216.40.44.79]) by kanga.kvack.org (Postfix) with ESMTP id 20E8A8D000D for ; Wed, 8 Jul 2020 04:27:03 -0400 (EDT) Received: from smtpin22.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id D9EA3180AD81A for ; Wed, 8 Jul 2020 08:27:02 +0000 (UTC) X-FDA: 77014228284.22.wave29_480b4c626ebb Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin22.hostedemail.com (Postfix) with ESMTP id AC18C18038E6B for ; Wed, 8 Jul 2020 08:27:02 +0000 (UTC) X-HE-Tag: wave29_480b4c626ebb X-Filterd-Recvd-Size: 5257 Received: from mail-lf1-f66.google.com (mail-lf1-f66.google.com [209.85.167.66]) by imf11.hostedemail.com (Postfix) with ESMTP for ; Wed, 8 Jul 2020 08:27:02 +0000 (UTC) Received: by mail-lf1-f66.google.com with SMTP id k15so26331019lfc.4 for ; Wed, 08 Jul 2020 01:27:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=shutemov-name.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=SOolC/vv83nDDMOzG10FTHkqfTRVAIjWH0PZ9g1P99E=; b=k96D0LhGIzJBEjseKx34L0lATj/LwM36St3znKXuTQIOWD+deqs9FlV1Nf5kc4ofLm Og1kxz3xZAS4KNpDxnt3cPjr8J9c3RwXr8uD7PXJkVwawvrFU0pMPWBQ/xoj8b9YZerD kGbtmrj994zW1MPftuIbLe57nFLSSr/aHycEUjKOp1RjnFOB+SJPJsoPXtzCp0kza9fj LEYjNS2HdJbyAJd/nW/dcLCjuYx4Dhz8YI/8F77dkc9c3/2DTP/igm5WOGEvvnZN7tXJ cECV3XdWxYJily5DxKNR9fpZ3ZjU/jvYyWWgLd2XE0Dy84ja5RNydmAdu4G9hCZGJSFK FBAw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=SOolC/vv83nDDMOzG10FTHkqfTRVAIjWH0PZ9g1P99E=; b=sPMEOvRKT9Ox3EKQ6ooxIaH5YrKCgVlesAR3YGrycq6GsorEjot/3XZdcSCKEgD4Zm wlnYpozEYN3X2VOqhk9/P8mSa+Igxgtmb5cN1dckHkiPwTGDMn4TDgA3v5U3eyPVSmSp vby806K0EeHiHaZ1nFZzJYEtIurpwhgaOX6sj3R3vCFlseQeLmNUiqh7W9SekiXtsoKQ uKlcC8IrlakQRuB9K8pjbfC/6LgLffM3jai+IW7muHcX9WkNVZAhhx+jJ+FG8PC9WpsR 2Ybxbf+M3O5mcbF2JvqLuSUUJ+OoZvcYZycX45tONzuNeTCwhZPEeCFvwZBtj3E4Pwa7 pM5w== X-Gm-Message-State: AOAM531jlmsc3SUCyPkSDmuBF3IvdyAc6CUwgDiR98CGbSsTAIZKE451 oMOpXvtT2PSGIdlpW5pCsCXHMw== X-Google-Smtp-Source: ABdhPJy5LQKzOYkmdjXfgpA68oHfAl4A56zFgFzUf1aCjCXhErM7MZQHShEd4/YI8LoBJY5hgyUG9A== X-Received: by 2002:ac2:52af:: with SMTP id r15mr36021294lfm.24.1594196820443; Wed, 08 Jul 2020 01:27:00 -0700 (PDT) Received: from box.localdomain ([86.57.175.117]) by smtp.gmail.com with ESMTPSA id q11sm10209307lfe.34.2020.07.08.01.26.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 08 Jul 2020 01:26:59 -0700 (PDT) Received: by box.localdomain (Postfix, from userid 1000) id C01C3102260; Wed, 8 Jul 2020 11:27:00 +0300 (+03) Date: Wed, 8 Jul 2020 11:27:00 +0300 From: "Kirill A. Shutemov" To: Wei Yang Cc: akpm@linux-foundation.org, kirill.shutemov@linux.intel.com, vbabka@suse.cz, yang.shi@linux.alibaba.com, thomas_os@shipmail.org, anshuman.khandual@arm.com, sean.j.christopherson@intel.com, peterx@redhat.com, aneesh.kumar@linux.ibm.com, willy@infradead.org, thellstrom@vmware.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, digetx@gmail.com Subject: Re: [Patch v3 4/4] mm/mremap: use pmd_addr_end to simplify the calculate of extent Message-ID: <20200708082700.ev7m5re42tupixqu@box> References: <20200708012453.36588-1-richard.weiyang@linux.alibaba.com> <20200708012453.36588-5-richard.weiyang@linux.alibaba.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200708012453.36588-5-richard.weiyang@linux.alibaba.com> X-Rspamd-Queue-Id: AC18C18038E6B X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam02 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, Jul 08, 2020 at 09:24:53AM +0800, Wei Yang wrote: > The purpose of this code is to calculate the smaller extent in old and > new range. Let's leverage pmd_addr_end() to do the calculation. > > Hope this would make the code easier to read. > > Signed-off-by: Wei Yang > --- > mm/mremap.c | 16 +++++++--------- > 1 file changed, 7 insertions(+), 9 deletions(-) > > diff --git a/mm/mremap.c b/mm/mremap.c > index f5f17d050617..76e7fdf567c3 100644 > --- a/mm/mremap.c > +++ b/mm/mremap.c > @@ -237,11 +237,12 @@ unsigned long move_page_tables(struct vm_area_struct *vma, > unsigned long new_addr, unsigned long len, > bool need_rmap_locks) > { > - unsigned long extent, next, old_end; > + unsigned long extent, old_next, new_next, old_end, new_end; > struct mmu_notifier_range range; > pmd_t *old_pmd, *new_pmd; > > old_end = old_addr + len; > + new_end = new_addr + len; > flush_cache_range(vma, old_addr, old_end); > > mmu_notifier_range_init(&range, MMU_NOTIFY_UNMAP, 0, vma, vma->vm_mm, > @@ -250,14 +251,11 @@ unsigned long move_page_tables(struct vm_area_struct *vma, > > for (; old_addr < old_end; old_addr += extent, new_addr += extent) { > cond_resched(); > - next = (old_addr + PMD_SIZE) & PMD_MASK; > - /* even if next overflowed, extent below will be ok */ > - extent = next - old_addr; > - if (extent > old_end - old_addr) > - extent = old_end - old_addr; > - next = (new_addr + PMD_SIZE) & PMD_MASK; > - if (extent > next - new_addr) > - extent = next - new_addr; > + > + old_next = pmd_addr_end(old_addr, old_end); > + new_next = pmd_addr_end(new_addr, new_end); > + extent = min((old_next - old_addr), (new_next - new_addr)); Nit: redundant parentheses. -- Kirill A. Shutemov