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=-6.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 F363DC47254 for ; Fri, 1 May 2020 12:24:30 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id B8E5B20708 for ; Fri, 1 May 2020 12:24:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="EbrurM0p" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B8E5B20708 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 5916A8E0006; Fri, 1 May 2020 08:24:30 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 541288E0001; Fri, 1 May 2020 08:24:30 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4573D8E0006; Fri, 1 May 2020 08:24:30 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0232.hostedemail.com [216.40.44.232]) by kanga.kvack.org (Postfix) with ESMTP id 2A8058E0001 for ; Fri, 1 May 2020 08:24:30 -0400 (EDT) Received: from smtpin16.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id D955C180AD811 for ; Fri, 1 May 2020 12:24:29 +0000 (UTC) X-FDA: 76768068258.16.goose55_7e8b1b362aa2c X-HE-Tag: goose55_7e8b1b362aa2c X-Filterd-Recvd-Size: 4594 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) by imf48.hostedemail.com (Postfix) with ESMTP for ; Fri, 1 May 2020 12:24:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.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=d8B/MysH0iSyYJt4VMjpzq137TPEbHeCixl/G5VtNO0=; b=EbrurM0pZcDW79I3d230iHROz9 UkQB7jjd+34VLhwrqzQzsYIXOkWHknFbSzg4pAtBlCYaEKHZZRruG0WgYK5KcDB1f6rtF3O0e4K/d ekRb6CyN3w1OiCOjlOs65VbScyvfKjQ9zRjHK5hZL4lRuP+ihXqRh/bAU9Pv4s6xUXVc8xQpldAwS 4Tpv8/Um7Sn5Up2qS39kAiEtbh5LiJMYy/adIvSNv+Ds5azkXz7rOj2RuF62kYavl1Pkp7MQPSukk CcGgkFcjo9ztRz8qLZcn1faB1fvxG7WW+FQPHazJeH5eMqnFWXsdRdQHPmWx3zIt89isbRH9t9JQU Y9W0GR0A==; Received: from hch by bombadil.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1jUUiR-0000wL-Oz; Fri, 01 May 2020 12:24:27 +0000 Date: Fri, 1 May 2020 05:24:27 -0700 From: Christoph Hellwig To: js1304@gmail.com Cc: Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Vlastimil Babka , Laura Abbott , "Aneesh Kumar K . V" , Mel Gorman , Michal Hocko , Johannes Weiner , Roman Gushchin , Minchan Kim , Rik van Riel , Christian Koenig , Huang Rui , Eric Biederman , "Rafael J . Wysocki" , Pavel Machek , kernel-team@lge.com, Christoph Hellwig , Joonsoo Kim Subject: Re: [PATCH v2 05/10] mm/gup: separate PageHighMem() and PageHighMemZone() use case Message-ID: <20200501122427.GB21897@infradead.org> References: <1588130803-20527-1-git-send-email-iamjoonsoo.kim@lge.com> <1588130803-20527-6-git-send-email-iamjoonsoo.kim@lge.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1588130803-20527-6-git-send-email-iamjoonsoo.kim@lge.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html 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 29, 2020 at 12:26:38PM +0900, js1304@gmail.com wrote: > From: Joonsoo Kim > > Until now, PageHighMem() is used for two different cases. One is to check > if there is a direct mapping for this page or not. The other is to check > the zone of this page, that is, weather it is the highmem type zone or not. > > Now, we have separate functions, PageHighMem() and PageHighMemZone() for > each cases. Use appropriate one. > > Note that there are some rules to determine the proper macro. > > 1. If PageHighMem() is called for checking if the direct mapping exists > or not, use PageHighMem(). > 2. If PageHighMem() is used to predict the previous gfp_flags for > this page, use PageHighMemZone(). The zone of the page is related to > the gfp_flags. > 3. If purpose of calling PageHighMem() is to count highmem page and > to interact with the system by using this count, use PageHighMemZone(). > This counter is usually used to calculate the available memory for an > kernel allocation and pages on the highmem zone cannot be available > for an kernel allocation. > 4. Otherwise, use PageHighMemZone(). It's safe since it's implementation > is just copy of the previous PageHighMem() implementation and won't > be changed. > > I apply the rule #2 for this patch. > > Acked-by: Roman Gushchin > Signed-off-by: Joonsoo Kim > --- > mm/gup.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/gup.c b/mm/gup.c > index 11fda53..9652eed 100644 > --- a/mm/gup.c > +++ b/mm/gup.c > @@ -1608,7 +1608,7 @@ static struct page *new_non_cma_page(struct page *page, unsigned long private) > */ > gfp_t gfp_mask = GFP_USER | __GFP_NOWARN; > > - if (PageHighMem(page)) > + if (PageHighMemZone(page)) > gfp_mask |= __GFP_HIGHMEM; I think this wants to stay PageHighMem. This migrates CMA pages to other places before doing a long term pin. Anything that didn't have a direct mapping before won't need one for the new page, which could also include non-highmem zones without a highmem mapping.