From: Peter Xu <peterx@redhat.com>
To: James Houghton <jthoughton@google.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>,
David Hildenbrand <david@redhat.com>,
Muchun Song <songmuchun@bytedance.com>,
David Rientjes <rientjes@google.com>,
Axel Rasmussen <axelrasmussen@google.com>,
Mina Almasry <almasrymina@google.com>,
Zach O'Keefe <zokeefe@google.com>,
Manish Mishra <manish.mishra@nutanix.com>,
Naoya Horiguchi <naoya.horiguchi@nec.com>,
"Dr . David Alan Gilbert" <dgilbert@redhat.com>,
"Matthew Wilcox (Oracle)" <willy@infradead.org>,
Vlastimil Babka <vbabka@suse.cz>,
Baolin Wang <baolin.wang@linux.alibaba.com>,
Miaohe Lin <linmiaohe@huawei.com>, Yang Shi <shy828301@gmail.com>,
Andrew Morton <akpm@linux-foundation.org>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 21/46] hugetlb: use struct hugetlb_pte for walk_hugetlb_range
Date: Thu, 19 Jan 2023 15:53:05 -0500 [thread overview]
Message-ID: <Y8mtsfYhR9sTw4Kn@x1n> (raw)
In-Reply-To: <CADrL8HVdL_NMdNq2mEemNCfwkYBAWnbqwyjsAYdQ2fF0iz34Hw@mail.gmail.com>
On Thu, Jan 19, 2023 at 11:42:26AM -0800, James Houghton wrote:
> - We avoid problems related to compound PTEs (the problem being: two
> threads racing to populate a contiguous and non-contiguous PTE that
> take up the same space could lead to user-detectable incorrect
> behavior. This isn't hard to fix; it will be when I send the arm64
> patches up.)
Could you elaborate this one a bit more?
> This might seem kind of contrived, but let's say you have a VM with 1T
> of memory, and you find 100 memory errors all in different 1G pages
> over the life of this VM (years, potentially). Having 10% of your
> memory be 4K-mapped is definitely worse than having 10% be 2M-mapped
> (lost performance and increased memory overhead). There might be other
> cases in the future where being able to have intermediate mapping
> sizes could be helpful.
This is not the norm, or is it? How the possibility of bad pages can
distribute over hosts over years? This can definitely affect how we should
target the intermediate level mappings.
Thanks,
--
Peter Xu
next prev parent reply other threads:[~2023-01-19 20:58 UTC|newest]
Thread overview: 126+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-05 10:17 [PATCH 00/46] Based on latest mm-unstable (85b44c25cd1e) James Houghton
2023-01-05 10:17 ` [PATCH 01/46] hugetlb: don't set PageUptodate for UFFDIO_CONTINUE James Houghton
2023-01-05 10:18 ` [PATCH 02/46] hugetlb: remove mk_huge_pte; it is unused James Houghton
2023-01-05 10:18 ` [PATCH 03/46] hugetlb: remove redundant pte_mkhuge in migration path James Houghton
2023-01-05 10:18 ` [PATCH 04/46] hugetlb: only adjust address ranges when VMAs want PMD sharing James Houghton
2023-01-05 10:18 ` [PATCH 05/46] hugetlb: add CONFIG_HUGETLB_HIGH_GRANULARITY_MAPPING James Houghton
2023-01-05 10:18 ` [PATCH 06/46] mm: add VM_HUGETLB_HGM VMA flag James Houghton
2023-01-05 10:18 ` [PATCH 07/46] hugetlb: rename __vma_shareable_flags_pmd to __vma_has_hugetlb_vma_lock James Houghton
2023-01-05 10:18 ` [PATCH 08/46] hugetlb: add HugeTLB HGM enablement helpers James Houghton
2023-01-05 10:18 ` [PATCH 09/46] mm: add MADV_SPLIT to enable HugeTLB HGM James Houghton
2023-01-05 15:05 ` kernel test robot
2023-01-05 15:29 ` David Hildenbrand
2023-01-10 0:01 ` Zach O'Keefe
2023-01-05 10:18 ` [PATCH 10/46] hugetlb: make huge_pte_lockptr take an explicit shift argument James Houghton
2023-01-05 10:18 ` [PATCH 11/46] hugetlb: add hugetlb_pte to track HugeTLB page table entries James Houghton
2023-01-05 16:06 ` kernel test robot
2023-01-05 10:18 ` [PATCH 12/46] hugetlb: add hugetlb_alloc_pmd and hugetlb_alloc_pte James Houghton
2023-01-05 10:18 ` [PATCH 13/46] hugetlb: add hugetlb_hgm_walk and hugetlb_walk_step James Houghton
2023-01-05 16:57 ` kernel test robot
2023-01-05 18:58 ` kernel test robot
2023-01-11 21:51 ` Peter Xu
2023-01-12 13:38 ` James Houghton
2023-01-05 10:18 ` [PATCH 14/46] hugetlb: add make_huge_pte_with_shift James Houghton
2023-01-05 10:18 ` [PATCH 15/46] hugetlb: make default arch_make_huge_pte understand small mappings James Houghton
2023-01-05 10:18 ` [PATCH 16/46] hugetlbfs: do a full walk to check if vma maps a page James Houghton
2023-01-05 10:18 ` [PATCH 17/46] hugetlb: make unmapping compatible with high-granularity mappings James Houghton
2023-01-05 10:18 ` [PATCH 18/46] hugetlb: add HGM support for hugetlb_change_protection James Houghton
2023-01-05 10:18 ` [PATCH 19/46] hugetlb: add HGM support for follow_hugetlb_page James Houghton
2023-01-05 22:26 ` Peter Xu
2023-01-12 18:02 ` Peter Xu
2023-01-12 18:06 ` James Houghton
2023-01-05 10:18 ` [PATCH 20/46] hugetlb: add HGM support for hugetlb_follow_page_mask James Houghton
2023-01-05 10:18 ` [PATCH 21/46] hugetlb: use struct hugetlb_pte for walk_hugetlb_range James Houghton
2023-01-05 22:42 ` Peter Xu
2023-01-11 22:58 ` Peter Xu
2023-01-12 14:06 ` James Houghton
2023-01-12 15:29 ` Peter Xu
2023-01-12 16:45 ` James Houghton
2023-01-12 16:55 ` James Houghton
2023-01-12 20:27 ` Peter Xu
2023-01-12 21:17 ` James Houghton
2023-01-12 21:33 ` Peter Xu
2023-01-16 10:17 ` David Hildenbrand
2023-01-17 23:11 ` James Houghton
2023-01-18 9:43 ` David Hildenbrand
2023-01-18 15:35 ` Peter Xu
2023-01-18 16:39 ` James Houghton
2023-01-18 18:21 ` David Hildenbrand
2023-01-18 19:28 ` Mike Kravetz
2023-01-19 16:57 ` James Houghton
2023-01-19 17:31 ` Mike Kravetz
2023-01-19 19:42 ` James Houghton
2023-01-19 20:53 ` Peter Xu [this message]
2023-01-19 22:45 ` James Houghton
2023-01-19 22:00 ` Mike Kravetz
2023-01-19 22:23 ` Peter Xu
2023-01-19 22:35 ` James Houghton
2023-01-19 23:07 ` Peter Xu
2023-01-19 23:26 ` James Houghton
2023-01-20 17:23 ` Peter Xu
2023-01-19 23:44 ` Mike Kravetz
2023-01-23 15:19 ` Peter Xu
2023-01-23 17:49 ` Mike Kravetz
2023-01-26 16:58 ` James Houghton
2023-01-26 20:30 ` Peter Xu
2023-01-27 21:02 ` James Houghton
2023-01-30 17:29 ` Peter Xu
2023-01-30 18:38 ` James Houghton
2023-01-30 21:14 ` Peter Xu
2023-02-01 0:24 ` James Houghton
2023-02-01 1:24 ` Peter Xu
2023-02-01 15:45 ` James Houghton
2023-02-01 15:56 ` David Hildenbrand
2023-02-01 17:58 ` James Houghton
2023-02-01 18:01 ` David Hildenbrand
2023-02-01 16:22 ` Peter Xu
2023-02-01 21:32 ` James Houghton
2023-02-01 21:51 ` Peter Xu
2023-02-02 0:24 ` James Houghton
2023-02-07 16:30 ` James Houghton
2023-02-07 22:46 ` James Houghton
2023-02-07 23:13 ` Peter Xu
2023-02-08 0:26 ` James Houghton
2023-02-08 16:16 ` Peter Xu
2023-02-09 16:43 ` James Houghton
2023-02-09 19:10 ` Peter Xu
2023-02-09 19:49 ` James Houghton
2023-02-09 20:22 ` Peter Xu
2023-01-18 17:08 ` David Hildenbrand
2023-01-05 10:18 ` [PATCH 22/46] mm: rmap: provide pte_order in page_vma_mapped_walk James Houghton
2023-01-05 10:18 ` [PATCH 23/46] mm: rmap: make page_vma_mapped_walk callers use pte_order James Houghton
2023-01-05 10:18 ` [PATCH 24/46] rmap: update hugetlb lock comment for HGM James Houghton
2023-01-05 10:18 ` [PATCH 25/46] hugetlb: update page_vma_mapped to do high-granularity walks James Houghton
2023-01-05 10:18 ` [PATCH 26/46] hugetlb: add HGM support for copy_hugetlb_page_range James Houghton
2023-01-05 10:18 ` [PATCH 27/46] hugetlb: add HGM support for move_hugetlb_page_tables James Houghton
2023-01-05 10:18 ` [PATCH 28/46] hugetlb: add HGM support for hugetlb_fault and hugetlb_no_page James Houghton
2023-01-05 10:18 ` [PATCH 29/46] rmap: in try_to_{migrate,unmap}_one, check head page for page flags James Houghton
2023-01-05 10:18 ` [PATCH 30/46] hugetlb: add high-granularity migration support James Houghton
2023-01-05 10:18 ` [PATCH 31/46] hugetlb: sort hstates in hugetlb_init_hstates James Houghton
2023-01-05 10:18 ` [PATCH 32/46] hugetlb: add for_each_hgm_shift James Houghton
2023-01-05 10:18 ` [PATCH 33/46] hugetlb: userfaultfd: add support for high-granularity UFFDIO_CONTINUE James Houghton
2023-01-05 10:18 ` [PATCH 34/46] hugetlb: userfaultfd: when using MADV_SPLIT, round addresses to PAGE_SIZE James Houghton
2023-01-06 15:13 ` Peter Xu
2023-01-10 14:50 ` James Houghton
2023-01-05 10:18 ` [PATCH 35/46] hugetlb: add MADV_COLLAPSE for hugetlb James Houghton
2023-01-10 20:04 ` James Houghton
2023-01-17 21:06 ` Peter Xu
2023-01-17 21:38 ` James Houghton
2023-01-17 21:54 ` Peter Xu
2023-01-19 22:37 ` Peter Xu
2023-01-19 23:06 ` James Houghton
2023-01-05 10:18 ` [PATCH 36/46] hugetlb: remove huge_pte_lock and huge_pte_lockptr James Houghton
2023-01-05 10:18 ` [PATCH 37/46] hugetlb: replace make_huge_pte with make_huge_pte_with_shift James Houghton
2023-01-05 10:18 ` [PATCH 38/46] mm: smaps: add stats for HugeTLB mapping size James Houghton
2023-01-05 10:18 ` [PATCH 39/46] hugetlb: x86: enable high-granularity mapping James Houghton
2023-01-12 20:07 ` James Houghton
2023-01-05 10:18 ` [PATCH 40/46] docs: hugetlb: update hugetlb and userfaultfd admin-guides with HGM info James Houghton
2023-01-05 10:18 ` [PATCH 41/46] docs: proc: include information about HugeTLB HGM James Houghton
2023-01-05 10:18 ` [PATCH 42/46] selftests/vm: add HugeTLB HGM to userfaultfd selftest James Houghton
2023-01-05 10:18 ` [PATCH 43/46] selftests/kvm: add HugeTLB HGM to KVM demand paging selftest James Houghton
2023-01-05 10:18 ` [PATCH 44/46] selftests/vm: add anon and shared hugetlb to migration test James Houghton
2023-01-05 10:18 ` [PATCH 45/46] selftests/vm: add hugetlb HGM test to migration selftest James Houghton
2023-01-05 10:18 ` [PATCH 46/46] selftests/vm: add HGM UFFDIO_CONTINUE and hwpoison tests James Houghton
2023-01-05 10:47 ` [PATCH 00/46] Based on latest mm-unstable (85b44c25cd1e) David Hildenbrand
2023-01-09 19:53 ` Mike Kravetz
2023-01-10 15:47 ` David Hildenbrand
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