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=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 62D51C56202 for ; Tue, 17 Nov 2020 15:06:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1864C24199 for ; Tue, 17 Nov 2020 15:06:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729995AbgKQPGS (ORCPT ); Tue, 17 Nov 2020 10:06:18 -0500 Received: from mx2.suse.de ([195.135.220.15]:59424 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726883AbgKQPGR (ORCPT ); Tue, 17 Nov 2020 10:06:17 -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 B5304AF95; Tue, 17 Nov 2020 15:06:14 +0000 (UTC) Date: Tue, 17 Nov 2020 16:06:10 +0100 From: Oscar Salvador To: Muchun Song Cc: corbet@lwn.net, mike.kravetz@oracle.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org, hpa@zytor.com, dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org, viro@zeniv.linux.org.uk, akpm@linux-foundation.org, paulmck@kernel.org, mchehab+huawei@kernel.org, pawan.kumar.gupta@linux.intel.com, rdunlap@infradead.org, oneukum@suse.com, anshuman.khandual@arm.com, jroedel@suse.de, almasrymina@google.com, rientjes@google.com, willy@infradead.org, mhocko@suse.com, duanxiongchun@bytedance.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH v4 05/21] mm/hugetlb: Introduce pgtable allocation/freeing helpers Message-ID: <20201117150604.GA15679@linux> References: <20201113105952.11638-1-songmuchun@bytedance.com> <20201113105952.11638-6-songmuchun@bytedance.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201113105952.11638-6-songmuchun@bytedance.com> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Nov 13, 2020 at 06:59:36PM +0800, Muchun Song wrote: > +#define page_huge_pte(page) ((page)->pmd_huge_pte) Seems you do not need this one anymore. > +void vmemmap_pgtable_free(struct page *page) > +{ > + struct page *pte_page, *t_page; > + > + list_for_each_entry_safe(pte_page, t_page, &page->lru, lru) { > + list_del(&pte_page->lru); > + pte_free_kernel(&init_mm, page_to_virt(pte_page)); > + } > +} > + > +int vmemmap_pgtable_prealloc(struct hstate *h, struct page *page) > +{ > + unsigned int nr = pgtable_pages_to_prealloc_per_hpage(h); > + > + /* Store preallocated pages on huge page lru list */ > + INIT_LIST_HEAD(&page->lru); > + > + while (nr--) { > + pte_t *pte_p; > + > + pte_p = pte_alloc_one_kernel(&init_mm); > + if (!pte_p) > + goto out; > + list_add(&virt_to_page(pte_p)->lru, &page->lru); > + } Definetely this looks better and easier to handle. Btw, did you explore Matthew's hint about instead of allocating a new page, using one of the ones you are going to free to store the ptes? I am not sure whether it is feasible at all though. > --- a/mm/hugetlb_vmemmap.h > +++ b/mm/hugetlb_vmemmap.h > @@ -9,12 +9,24 @@ > #ifndef _LINUX_HUGETLB_VMEMMAP_H > #define _LINUX_HUGETLB_VMEMMAP_H > #include > +#include why do we need this here? -- Oscar Salvador SUSE L3