From: Matthew Wilcox <willy@infradead.org>
To: linux-mm@kvack.org
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
Will Deacon <will@kernel.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Russell King <linux@armlinux.org.uk>,
Geert Uytterhoeven <geert@linux-m68k.org>,
linux-m68k@lists.linux-m68k.org
Subject: [PATCH 2/7] mm: Move pt_mm within struct page
Date: Tue, 28 Apr 2020 12:44:44 -0700 [thread overview]
Message-ID: <20200428194449.22615-3-willy@infradead.org> (raw)
In-Reply-To: <20200428194449.22615-1-willy@infradead.org>
From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Instead of a per-arch word within struct page, use a formerly reserved
word. This word is shared with page->mapping, so it must be cleared
before being freed as it is checked in free_pages().
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
arch/x86/mm/pgtable.c | 1 +
include/linux/mm_types.h | 7 ++-----
2 files changed, 3 insertions(+), 5 deletions(-)
diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c
index 7bd2c3a52297..f5f46737aea0 100644
--- a/arch/x86/mm/pgtable.c
+++ b/arch/x86/mm/pgtable.c
@@ -95,6 +95,7 @@ static inline void pgd_list_del(pgd_t *pgd)
struct page *page = virt_to_page(pgd);
list_del(&page->lru);
+ page->pt_mm = NULL;
}
#define UNSHARED_PTRS_PER_PGD \
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index 9bb34e2cd5a5..7efa12f4626f 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -149,11 +149,8 @@ struct page {
pgtable_t pmd_huge_pte;
};
};
- unsigned long _pt_pad_2; /* mapping */
- union {
- struct mm_struct *pt_mm; /* x86 pgds only */
- atomic_t pt_frag_refcount; /* powerpc */
- };
+ struct mm_struct *pt_mm;
+ atomic_t pt_frag_refcount; /* powerpc */
#if ALLOC_SPLIT_PTLOCKS
spinlock_t *ptl;
#else
--
2.26.2
next prev parent reply other threads:[~2020-04-28 19:44 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-28 19:44 [PATCH 0/7] Record the mm_struct in the page table pages Matthew Wilcox
2020-04-28 19:44 ` [PATCH 1/7] mm: Document x86 uses a linked list of pgds Matthew Wilcox
2020-04-28 21:41 ` Ira Weiny
2020-04-28 22:52 ` Matthew Wilcox
2020-04-29 18:29 ` Ira Weiny
2020-04-28 19:44 ` Matthew Wilcox [this message]
2020-04-29 7:34 ` [PATCH 2/7] mm: Move pt_mm within struct page Geert Uytterhoeven
2020-04-29 12:53 ` Matthew Wilcox
2020-04-28 19:44 ` [PATCH 3/7] arm: Thread mm_struct throughout page table allocation Matthew Wilcox
2020-04-28 19:44 ` [PATCH 4/7] arm64: " Matthew Wilcox
2020-04-29 9:58 ` Mark Rutland
2020-04-28 19:44 ` [PATCH 5/7] m68k: " Matthew Wilcox
2020-04-29 7:44 ` Geert Uytterhoeven
2020-04-28 19:44 ` [PATCH 6/7] mm: Set pt_mm in PTE constructor Matthew Wilcox
2020-04-29 7:46 ` Geert Uytterhoeven
2020-04-28 19:44 ` [PATCH 7/7] mm: Set pt_mm in PMD constructor Matthew Wilcox
2020-04-29 0:52 ` Kirill A. Shutemov
2020-04-29 0:26 ` [PATCH 0/7] Record the mm_struct in the page table pages Kirill A. Shutemov
2020-04-29 1:51 ` Matthew Wilcox
2020-05-24 7:42 ` Mike Rapoport
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