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=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,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 164BCC433E0 for ; Wed, 27 Jan 2021 10:45:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C26632076E for ; Wed, 27 Jan 2021 10:45:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236142AbhA0KpX (ORCPT ); Wed, 27 Jan 2021 05:45:23 -0500 Received: from mx2.suse.de ([195.135.220.15]:35850 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231570AbhA0KkY (ORCPT ); Wed, 27 Jan 2021 05:40:24 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1611743975; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=l6uF3roNeJhRHw5q8sy79omE8Ub4IQK2TXpHusNPPLw=; b=hr1t+qt3MXNaAiulIwQsmIORaGyAw7LIhuaf1nNnPzfdPfezgJLxsslx7wLQWjiw5Vklua HaIVG2Re2E5LSHUeYTZEqtBpGpv5ivZ/h+OUe4wdhF6eQTilnk6qGiM8/uy/vEzETOPqmf SNmrLqVPjCf0b0TNeOpyKamp7T2jjcU= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 5FBC3AEAC; Wed, 27 Jan 2021 10:39:35 +0000 (UTC) Date: Wed, 27 Jan 2021 11:39:34 +0100 From: Michal Hocko To: Mike Kravetz Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Naoya Horiguchi , Muchun Song , David Hildenbrand , Oscar Salvador , Matthew Wilcox , Miaohe Lin , Andrew Morton Subject: Re: [PATCH v3 4/5] hugetlb: convert PageHugeTemporary() to HPageTemporary flag Message-ID: <20210127103934.GJ827@dhcp22.suse.cz> References: <20210122195231.324857-1-mike.kravetz@oracle.com> <20210122195231.324857-5-mike.kravetz@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210122195231.324857-5-mike.kravetz@oracle.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri 22-01-21 11:52:30, Mike Kravetz wrote: > Use new hugetlb specific HPageTemporary flag to replace the > PageHugeTemporary() interfaces. PageHugeTemporary does contain > a PageHuge() check. However, this interface is only used within > hugetlb code where we know we are dealing with a hugetlb page. > Therefore, the check can be eliminated. A dedicated flag is definitely something I would go for if that was available back then when I introduced it. > Signed-off-by: Mike Kravetz > Reviewed-by: Oscar Salvador Acked-by: Michal Hocko Thanks! > --- > include/linux/hugetlb.h | 6 ++++++ > mm/hugetlb.c | 36 +++++++----------------------------- > 2 files changed, 13 insertions(+), 29 deletions(-) > > diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h > index cd1960541f2a..3c86c3a0e144 100644 > --- a/include/linux/hugetlb.h > +++ b/include/linux/hugetlb.h > @@ -483,10 +483,15 @@ unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr, > * HPG_migratable - Set after a newly allocated page is added to the page > * cache and/or page tables. Indicates the page is a candidate for > * migration. > + * HPG_temporary - - Set on a page that is temporarily allocated from the buddy > + * allocator. Typically used for migration target pages when no pages > + * are available in the pool. The hugetlb free page path will > + * immediately free pages with this flag set to the buddy allocator. > */ > enum hugetlb_page_flags { > HPG_restore_reserve = 0, > HPG_migratable, > + HPG_temporary, > __NR_HPAGEFLAGS, > }; > > @@ -530,6 +535,7 @@ static inline void ClearHPage##uname(struct page *page) \ > */ > HPAGEFLAG(RestoreReserve, restore_reserve) > HPAGEFLAG(Migratable, migratable) > +HPAGEFLAG(Temporary, temporary) > > #ifdef CONFIG_HUGETLB_PAGE > > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > index 4da1a29ac5e2..70ffa1027988 100644 > --- a/mm/hugetlb.c > +++ b/mm/hugetlb.c > @@ -1353,28 +1353,6 @@ struct hstate *size_to_hstate(unsigned long size) > return NULL; > } > > -/* > - * Internal hugetlb specific page flag. Do not use outside of the hugetlb > - * code > - */ > -static inline bool PageHugeTemporary(struct page *page) > -{ > - if (!PageHuge(page)) > - return false; > - > - return (unsigned long)page[2].mapping == -1U; > -} > - > -static inline void SetPageHugeTemporary(struct page *page) > -{ > - page[2].mapping = (void *)-1U; > -} > - > -static inline void ClearPageHugeTemporary(struct page *page) > -{ > - page[2].mapping = NULL; > -} > - > static void __free_huge_page(struct page *page) > { > /* > @@ -1422,9 +1400,9 @@ static void __free_huge_page(struct page *page) > if (restore_reserve) > h->resv_huge_pages++; > > - if (PageHugeTemporary(page)) { > + if (HPageTemporary(page)) { > list_del(&page->lru); > - ClearPageHugeTemporary(page); > + ClearHPageTemporary(page); > update_and_free_page(h, page); > } else if (h->surplus_huge_pages_node[nid]) { > /* remove the page from active list */ > @@ -1860,7 +1838,7 @@ static struct page *alloc_surplus_huge_page(struct hstate *h, gfp_t gfp_mask, > * codeflow > */ > if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) { > - SetPageHugeTemporary(page); > + SetHPageTemporary(page); > spin_unlock(&hugetlb_lock); > put_page(page); > return NULL; > @@ -1891,7 +1869,7 @@ static struct page *alloc_migrate_huge_page(struct hstate *h, gfp_t gfp_mask, > * We do not account these pages as surplus because they are only > * temporary and will be released properly on the last reference > */ > - SetPageHugeTemporary(page); > + SetHPageTemporary(page); > > return page; > } > @@ -5612,12 +5590,12 @@ void move_hugetlb_state(struct page *oldpage, struct page *newpage, int reason) > * here as well otherwise the global surplus count will not match > * the per-node's. > */ > - if (PageHugeTemporary(newpage)) { > + if (HPageTemporary(newpage)) { > int old_nid = page_to_nid(oldpage); > int new_nid = page_to_nid(newpage); > > - SetPageHugeTemporary(oldpage); > - ClearPageHugeTemporary(newpage); > + SetHPageTemporary(oldpage); > + ClearHPageTemporary(newpage); > > spin_lock(&hugetlb_lock); > if (h->surplus_huge_pages_node[old_nid]) { > -- > 2.29.2 -- Michal Hocko SUSE Labs