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=-8.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,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 7946CC4361B for ; Thu, 10 Dec 2020 11:41:12 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 0B23423D57 for ; Thu, 10 Dec 2020 11:41:11 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0B23423D57 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 7D0496B006C; Thu, 10 Dec 2020 06:41:11 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 77FF56B006E; Thu, 10 Dec 2020 06:41:11 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 670536B0070; Thu, 10 Dec 2020 06:41:11 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0218.hostedemail.com [216.40.44.218]) by kanga.kvack.org (Postfix) with ESMTP id 4E52E6B006C for ; Thu, 10 Dec 2020 06:41:11 -0500 (EST) Received: from smtpin07.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 1E45C824999B for ; Thu, 10 Dec 2020 11:41:11 +0000 (UTC) X-FDA: 77577181542.07.metal73_5c05433273f8 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin07.hostedemail.com (Postfix) with ESMTP id 0170C1803F9AA for ; Thu, 10 Dec 2020 11:41:10 +0000 (UTC) X-HE-Tag: metal73_5c05433273f8 X-Filterd-Recvd-Size: 3224 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf40.hostedemail.com (Postfix) with ESMTP for ; Thu, 10 Dec 2020 11:41:10 +0000 (UTC) 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 0079EAF16; Thu, 10 Dec 2020 11:41:06 +0000 (UTC) Date: Thu, 10 Dec 2020 11:04:54 +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, song.bao.hua@hisilicon.com, david@redhat.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 v8 09/12] mm/hugetlb: Add a kernel parameter hugetlb_free_vmemmap Message-ID: <20201210100454.GB3613@localhost.localdomain> References: <20201210035526.38938-1-songmuchun@bytedance.com> <20201210035526.38938-10-songmuchun@bytedance.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201210035526.38938-10-songmuchun@bytedance.com> 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 Thu, Dec 10, 2020 at 11:55:23AM +0800, Muchun Song wrote: > +hugetlb_free_vmemmap > + When CONFIG_HUGETLB_PAGE_FREE_VMEMMAP is set, this enables freeing > + unused vmemmap pages associated each HugeTLB page. ^^^ with > - if (end - start < PAGES_PER_SECTION * sizeof(struct page)) > + if (is_hugetlb_free_vmemmap_enabled()) > + err = vmemmap_populate_basepages(start, end, node, NULL); > + else if (end - start < PAGES_PER_SECTION * sizeof(struct page)) > err = vmemmap_populate_basepages(start, end, node, NULL); Not sure if joining those in an OR makes se.se > else if (boot_cpu_has(X86_FEATURE_PSE)) > err = vmemmap_populate_hugepages(start, end, node, altmap); > @@ -1610,7 +1613,8 @@ void register_page_bootmem_memmap(unsigned long section_nr, > } > get_page_bootmem(section_nr, pud_page(*pud), MIX_SECTION_INFO); > > - if (!boot_cpu_has(X86_FEATURE_PSE)) { > + if (!boot_cpu_has(X86_FEATURE_PSE) || > + is_hugetlb_free_vmemmap_enabled()) { I would add a variable at the beginning called "basepages_populated" that holds the result of those two conditions. I am not sure if it slightly improves the code as the conditions do not need to be rechecked, but the readibility a bit. > +bool hugetlb_free_vmemmap_enabled; > + > +static int __init early_hugetlb_free_vmemmap_param(char *buf) > +{ > + if (!buf) > + return -EINVAL; > + > + /* We cannot optimize if a "struct page" crosses page boundaries. */ I think this comment belongs to the last patch. -- Oscar Salvador SUSE L3