From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B1A4D13AEB for ; Fri, 29 Dec 2023 20:01:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="A3TXg9Ro" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7EF3BC433C9; Fri, 29 Dec 2023 20:01:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1703880088; bh=+i3tFYklOBOR6b9fhCStfVENfJQFEoQ9zqPRvCDEWbQ=; h=Date:To:From:Subject:From; b=A3TXg9Ro9+JqRdSgbHs7+LPvvYJztF1ZN/O7fKYm7podR1MmKfLpUQNifRqMsOjya rk+X8eBxS7PRy4X3IRMW1uvP7fS0AoyWz8LtyB0VzpIT4SqcJWYBh2/LACD/JaVnER SoobQK6/ijyU9yuliiAHeLHwt3JQb8EtP5kZkcf4= Date: Fri, 29 Dec 2023 12:01:28 -0800 To: mm-commits@vger.kernel.org,willy@infradead.org,songmuchun@bytedance.com,ryan.roberts@arm.com,peterx@redhat.com,muchun.song@linux.dev,hughd@google.com,fengwei.yin@intel.com,david@redhat.com,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-stable] mm-rmap-introduce-and-use-hugetlb_try_share_anon_rmap.patch removed from -mm tree Message-Id: <20231229200128.7EF3BC433C9@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: mm/rmap: introduce and use hugetlb_try_share_anon_rmap() has been removed from the -mm tree. Its filename was mm-rmap-introduce-and-use-hugetlb_try_share_anon_rmap.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: David Hildenbrand Subject: mm/rmap: introduce and use hugetlb_try_share_anon_rmap() Date: Wed, 20 Dec 2023 23:44:29 +0100 hugetlb rmap handling differs quite a lot from "ordinary" rmap code. For example, hugetlb currently only supports entire mappings, and treats any mapping as mapped using a single "logical PTE". Let's move it out of the way so we can overhaul our "ordinary" rmap. implementation/interface. So let's introduce and use hugetlb_try_dup_anon_rmap() to make all hugetlb handling use dedicated hugetlb_* rmap functions. Add sanity checks that we end up with the right folios in the right functions. Note that try_to_unmap_one() does not need care. Easy to spot because among all that nasty hugetlb special-casing in that function, we're not using set_huge_pte_at() on the anon path -- well, and that code assumes that we would want to swapout. Link: https://lkml.kernel.org/r/20231220224504.646757-6-david@redhat.com Signed-off-by: David Hildenbrand Reviewed-by: Yin Fengwei Reviewed-by: Ryan Roberts Cc: Hugh Dickins Cc: Matthew Wilcox (Oracle) Cc: Muchun Song Cc: Muchun Song Cc: Peter Xu Signed-off-by: Andrew Morton --- include/linux/rmap.h | 25 +++++++++++++++++++++++++ mm/rmap.c | 15 ++++++++++----- 2 files changed, 35 insertions(+), 5 deletions(-) --- a/include/linux/rmap.h~mm-rmap-introduce-and-use-hugetlb_try_share_anon_rmap +++ a/include/linux/rmap.h @@ -227,6 +227,30 @@ static inline int hugetlb_try_dup_anon_r return 0; } +/* See page_try_share_anon_rmap() */ +static inline int hugetlb_try_share_anon_rmap(struct folio *folio) +{ + VM_WARN_ON_FOLIO(!folio_test_hugetlb(folio), folio); + VM_WARN_ON_FOLIO(!folio_test_anon(folio), folio); + VM_WARN_ON_FOLIO(!PageAnonExclusive(&folio->page), folio); + + /* Paired with the memory barrier in try_grab_folio(). */ + if (IS_ENABLED(CONFIG_HAVE_FAST_GUP)) + smp_mb(); + + if (unlikely(folio_maybe_dma_pinned(folio))) + return -EBUSY; + ClearPageAnonExclusive(&folio->page); + + /* + * This is conceptually a smp_wmb() paired with the smp_rmb() in + * gup_must_unshare(). + */ + if (IS_ENABLED(CONFIG_HAVE_FAST_GUP)) + smp_mb__after_atomic(); + return 0; +} + static inline void hugetlb_add_file_rmap(struct folio *folio) { VM_WARN_ON_FOLIO(!folio_test_hugetlb(folio), folio); @@ -331,6 +355,7 @@ dup: */ static inline int page_try_share_anon_rmap(struct page *page) { + VM_WARN_ON(folio_test_hugetlb(page_folio(page))); VM_BUG_ON_PAGE(!PageAnon(page) || !PageAnonExclusive(page), page); /* device private pages cannot get pinned via GUP. */ --- a/mm/rmap.c~mm-rmap-introduce-and-use-hugetlb_try_share_anon_rmap +++ a/mm/rmap.c @@ -2149,13 +2149,18 @@ static bool try_to_migrate_one(struct fo !anon_exclusive, subpage); /* See page_try_share_anon_rmap(): clear PTE first. */ - if (anon_exclusive && - page_try_share_anon_rmap(subpage)) { - if (folio_test_hugetlb(folio)) + if (folio_test_hugetlb(folio)) { + if (anon_exclusive && + hugetlb_try_share_anon_rmap(folio)) { set_huge_pte_at(mm, address, pvmw.pte, pteval, hsz); - else - set_pte_at(mm, address, pvmw.pte, pteval); + ret = false; + page_vma_mapped_walk_done(&pvmw); + break; + } + } else if (anon_exclusive && + page_try_share_anon_rmap(subpage)) { + set_pte_at(mm, address, pvmw.pte, pteval); ret = false; page_vma_mapped_walk_done(&pvmw); break; _ Patches currently in -mm which might be from david@redhat.com are