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=-10.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 EB9F7C433DB for ; Fri, 5 Feb 2021 09:00:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A4D3264F3C for ; Fri, 5 Feb 2021 09:00:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229684AbhBEJAg (ORCPT ); Fri, 5 Feb 2021 04:00:36 -0500 Received: from mx2.suse.de ([195.135.220.15]:55528 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229558AbhBEJA0 (ORCPT ); Fri, 5 Feb 2021 04:00:26 -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 61DB0AEA8; Fri, 5 Feb 2021 08:59:44 +0000 (UTC) Date: Fri, 5 Feb 2021 09:59:40 +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, naoya.horiguchi@nec.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 v14 0/8] Free some vmemmap pages of HugeTLB page Message-ID: <20210205085940.GD13848@linux> References: <20210204035043.36609-1-songmuchun@bytedance.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210204035043.36609-1-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 Thu, Feb 04, 2021 at 11:50:35AM +0800, Muchun Song wrote: > Changelog in v13 -> v14: > - Refuse to free the HugeTLB page when the system is under memory pressure. > - Use GFP_ATOMIC to allocate vmemmap pages instead of GFP_KERNEL. > - Rebase to linux-next 20210202. > - Fix and add some comments for vmemmap_remap_free(). What has happened to [1] ? AFAIK we still need it, right? If not, could you explain why? [1] https://patchwork.kernel.org/project/linux-mm/patch/20210117151053.24600-7-songmuchun@bytedance.com/ > > Thanks to Oscar, Mike, David H and David R's suggestions and review. > > Changelog in v12 -> v13: > - Remove VM_WARN_ON_PAGE macro. > - Add more comments in vmemmap_pte_range() and vmemmap_remap_free(). > > Thanks to Oscar and Mike's suggestions and review. > > Changelog in v11 -> v12: > - Move VM_WARN_ON_PAGE to a separate patch. > - Call __free_hugepage() with hugetlb_lock (See patch #5.) to serialize > with dissolve_free_huge_page(). It is to prepare for patch #9. > - Introduce PageHugeInflight. See patch #9. > > Changelog in v10 -> v11: > - Fix compiler error when !CONFIG_HUGETLB_PAGE_FREE_VMEMMAP. > - Rework some comments and commit changes. > - Rework vmemmap_remap_free() to 3 parameters. > > Thanks to Oscar and Mike's suggestions and review. > > Changelog in v9 -> v10: > - Fix a bug in patch #11. Thanks to Oscar for pointing that out. > - Rework some commit log or comments. Thanks Mike and Oscar for the suggestions. > - Drop VMEMMAP_TAIL_PAGE_REUSE in the patch #3. > > Thank you very much Mike and Oscar for reviewing the code. > > Changelog in v8 -> v9: > - Rework some code. Very thanks to Oscar. > - Put all the non-hugetlb vmemmap functions under sparsemem-vmemmap.c. > > Changelog in v7 -> v8: > - Adjust the order of patches. > > Very thanks to David and Oscar. Your suggestions are very valuable. > > Changelog in v6 -> v7: > - Rebase to linux-next 20201130 > - Do not use basepage mapping for vmemmap when this feature is disabled. > - Rework some patchs. > [PATCH v6 08/16] mm/hugetlb: Free the vmemmap pages associated with each hugetlb page > [PATCH v6 10/16] mm/hugetlb: Allocate the vmemmap pages associated with each hugetlb page > > Thanks to Oscar and Barry. > > Changelog in v5 -> v6: > - Disable PMD/huge page mapping of vmemmap if this feature was enabled. > - Simplify the first version code. > > Changelog in v4 -> v5: > - Rework somme comments and code in the [PATCH v4 04/21] and [PATCH v4 05/21]. > > Thanks to Mike and Oscar's suggestions. > > Changelog in v3 -> v4: > - Move all the vmemmap functions to hugetlb_vmemmap.c. > - Make the CONFIG_HUGETLB_PAGE_FREE_VMEMMAP default to y, if we want to > disable this feature, we should disable it by a boot/kernel command line. > - Remove vmemmap_pgtable_{init, deposit, withdraw}() helper functions. > - Initialize page table lock for vmemmap through core_initcall mechanism. > > Thanks for Mike and Oscar's suggestions. > > Changelog in v2 -> v3: > - Rename some helps function name. Thanks Mike. > - Rework some code. Thanks Mike and Oscar. > - Remap the tail vmemmap page with PAGE_KERNEL_RO instead of PAGE_KERNEL. > Thanks Matthew. > - Add some overhead analysis in the cover letter. > - Use vmemap pmd table lock instead of a hugetlb specific global lock. > > Changelog in v1 -> v2: > - Fix do not call dissolve_compound_page in alloc_huge_page_vmemmap(). > - Fix some typo and code style problems. > - Remove unused handle_vmemmap_fault(). > - Merge some commits to one commit suggested by Mike. > > Muchun Song (8): > mm: memory_hotplug: factor out bootmem core functions to > bootmem_info.c > mm: hugetlb: introduce a new config HUGETLB_PAGE_FREE_VMEMMAP > mm: hugetlb: free the vmemmap pages associated with each HugeTLB page > mm: hugetlb: alloc the vmemmap pages associated with each HugeTLB page > mm: hugetlb: add a kernel parameter hugetlb_free_vmemmap > mm: hugetlb: introduce nr_free_vmemmap_pages in the struct hstate > mm: hugetlb: gather discrete indexes of tail page > mm: hugetlb: optimize the code with the help of the compiler > > Documentation/admin-guide/kernel-parameters.txt | 14 ++ > Documentation/admin-guide/mm/hugetlbpage.rst | 3 + > arch/x86/mm/init_64.c | 13 +- > fs/Kconfig | 6 + > include/linux/bootmem_info.h | 65 +++++ > include/linux/hugetlb.h | 43 +++- > include/linux/hugetlb_cgroup.h | 19 +- > include/linux/memory_hotplug.h | 27 -- > include/linux/mm.h | 5 + > mm/Makefile | 2 + > mm/bootmem_info.c | 124 ++++++++++ > mm/hugetlb.c | 23 +- > mm/hugetlb_vmemmap.c | 314 ++++++++++++++++++++++++ > mm/hugetlb_vmemmap.h | 33 +++ > mm/memory_hotplug.c | 116 --------- > mm/sparse-vmemmap.c | 280 +++++++++++++++++++++ > mm/sparse.c | 1 + > 17 files changed, 930 insertions(+), 158 deletions(-) > create mode 100644 include/linux/bootmem_info.h > create mode 100644 mm/bootmem_info.c > create mode 100644 mm/hugetlb_vmemmap.c > create mode 100644 mm/hugetlb_vmemmap.h > > -- > 2.11.0 > > -- Oscar Salvador SUSE L3