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=-13.8 required=3.0 tests=BAYES_00, 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 619B2C43332 for ; Wed, 20 Jan 2021 10:30:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 03C6F2333F for ; Wed, 20 Jan 2021 10:30:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732813AbhATKUE (ORCPT ); Wed, 20 Jan 2021 05:20:04 -0500 Received: from mx2.suse.de ([195.135.220.15]:42660 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729997AbhATKKB (ORCPT ); Wed, 20 Jan 2021 05:10:01 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 7C8BAAC97; Wed, 20 Jan 2021 10:09:19 +0000 (UTC) Date: Wed, 20 Jan 2021 11:09:13 +0100 From: Oscar Salvador To: Mike Kravetz Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Michal Hocko , Naoya Horiguchi , Muchun Song , David Hildenbrand , Matthew Wilcox , Andrew Morton Subject: Re: [PATCH v2 4/5] hugetlb: convert PageHugeTemporary() to HPageTemporary flag Message-ID: <20210120100913.GC4752@localhost.localdomain> References: <20210120013049.311822-1-mike.kravetz@oracle.com> <20210120013049.311822-5-mike.kravetz@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210120013049.311822-5-mike.kravetz@oracle.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 19, 2021 at 05:30:48PM -0800, Mike Kravetz wrote: > Use new hugetlb specific HPageTemporary flag to replace the > PageHugeTemporary() interfaces. > > Signed-off-by: Mike Kravetz I would have added a brief comment explaining why it is ok to drop the PageHuge() check in PageHugeTemporary. AFAICS, the paths checking it already know they are handling with a hugetlb page, but still it is better to mention it in the changelog in case someone wonders. Other than that looks good to me: Reviewed-by: Oscar Salvador > --- > 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 1e17529c8b81..ec329b9cc0fc 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, > }; > > @@ -534,6 +539,7 @@ 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 6e32751489e8..0d2bfc2b6adc 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 */ > @@ -1863,7 +1841,7 @@ 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; > @@ -1894,7 +1872,7 @@ 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; > } > @@ -5607,12 +5585,12 @@ 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 > -- Oscar Salvador SUSE L3